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Home My WebLink AboutDWQ-2024-001042 Draft 2024 Integrated Report on Water Quality Prepared by Utah Department of Environmental Quality Division of Water Quality 2 Table of Contents Table of Contents................................................................................................................................................................ 2 Abbreviations...................................................................................................................................................................... 5 Figures ............................................................................................................................................................................... 9 Tables .............................................................................................................................................................................. 10 Executive Summary.......................................................................................................................................................... 11 Purpose ............................................................................................................................................................................ 11 Scope ............................................................................................................................................................................... 11 Methods ........................................................................................................................................................................... 11 Data Collection ................................................................................................................................................................. 11 Delistings .......................................................................................................................................................................... 12 AU Resegmentation ......................................................................................................................................................... 12 Public Comment Process ................................................................................................................................................. 13 Findings ............................................................................................................................................................................ 13 Assessment Totals ....................................................................................................................................................... 14 River, Stream and Canal Assessments ........................................................................................................................ 15 Lake, Reservoir, and Pond Assessments ..................................................................................................................... 17 Delistings .......................................................................................................................................................................... 20 Recommendations ........................................................................................................................................................... 21 Priority Waters .................................................................................................................................................................. 21 Chapter 1 303(d) Assessment Methods............................................................................................................................ 22 Introduction ...................................................................................................................................................................... 22 The Clean Water Act and the Integrated Report .......................................................................................................... 22 Assessment Categories for Surface Waters ................................................................................................................. 22 Utah’s Numeric Criteria and Beneficial Uses ................................................................................................................ 13 Assessed Parameters .................................................................................................................................................. 14 Assessment Process and Time Frames ........................................................................................................................... 15 Developing the Methods ............................................................................................................................................... 15 Public Review of the Methods Process and Schedule ................................................................................................. 15 Call for Readily Available Data and Schedule .............................................................................................................. 15 Developing the Components of the Draft Integrated Report and 303(d) List ............................................................... 18 Public Review of the 303(d) List ................................................................................................................................... 19 Finalizing the Integrated Report and 303(d) List .......................................................................................................... 20 Scope of the Assessment ................................................................................................................................................. 20 Waters of the State ....................................................................................................................................................... 20 3 Waterbody Types.......................................................................................................................................................... 21 Assessment Units ......................................................................................................................................................... 21 Waters Within and Shared with Other States ............................................................................................................... 23 Data Quality ...................................................................................................................................................................... 24 Credible Data Defined .................................................................................................................................................. 24 Components for Credible Data ..................................................................................................................................... 24 Credible Data Matrices ................................................................................................................................................. 26 Data Submission Process ................................................................................................................................................. 32 Type of Data to Submit ................................................................................................................................................. 32 Period of Record ........................................................................................................................................................... 32 Data Submission Tools................................................................................................................................................. 33 Data Preparation for Conventional and Toxic Assessments for All Waters ...................................................................... 33 Results below Detection Limits..................................................................................................................................... 33 Duplicate and Replicate Results................................................................................................................................... 33 Initial Assessment: Monitoring Location Site Level ...................................................................................................... 34 Assessments Specific to Rivers, Streams, and Canals .................................................................................................... 34 Conventional Parameter Assessments ........................................................................................................................ 34 Nutrient Assessments Specific to Headwater Streams ................................................................................................ 40 Narrative Standards: Biological Assessments .............................................................................................................. 45 Assessments Specific to Lakes, Reservoirs, and Ponds .................................................................................................. 48 Assessment Overview .................................................................................................................................................. 48 Tier I Assessment ......................................................................................................................................................... 48 Tier II Assessment ........................................................................................................................................................ 54 Great Salt Lake ............................................................................................................................................................. 56 Toxic Parameter Assessments for All Waters ................................................................................................................... 57 Equation-Based Toxic Parameters ............................................................................................................................... 57 Assessment Process .................................................................................................................................................... 58 Data Preparation........................................................................................................................................................... 59 Assessment Process .................................................................................................................................................... 60 Pollution Indicator Assessments for All Waters................................................................................................................. 65 Narrative Standards for All Waters .................................................................................................................................... 65 Fish Kills ....................................................................................................................................................................... 66 Harmful Algal Blooms (HAB) ........................................................................................................................................ 67 Fish Tissue Assessments and Consumption Health Advisories................................................................................... 67 Determinations of Impairment: All Assessment Units ....................................................................................................... 69 Individual Assessment of Water Quality Standards ...................................................................................................... 70 Conflicting Assessments of Water Quality Standards .................................................................................................. 70 Aggregation of Site-Specific Assessments to Assessment Unit Categories ................................................................ 70 Secondary Review ........................................................................................................................................................ 71 Identifying Causes of Impairments .................................................................................................................................... 72 4 Pollutants ...................................................................................................................................................................... 73 Unknown Sources ........................................................................................................................................................ 73 Natural Conditions ........................................................................................................................................................ 73 Revising the 303(d) List and Other Categorical Assessments .......................................................................................... 74 Category 4A .................................................................................................................................................................. 74 Category 4B .................................................................................................................................................................. 75 Category 4C ................................................................................................................................................................. 75 Delistings ...................................................................................................................................................................... 76 Previous Categorical Listings ....................................................................................................................................... 79 303(d) Vision and TMDL Priority Development ................................................................................................................. 80 Revision Requests between Cycles .................................................................................................................................. 80 Literature Cited ................................................................................................................................................................ 81 Chapter 2 Assessments Specific to Lakes, Reservoirs, and Ponds ................................................................................. 83 Chapter 3 Assessments Specific to Rivers, Streams and Canals ................................................................................... 89 Appendix 1 ....................................................................................................................................................................... 86 Data Quality Guideline Examples ..................................................................................................................................... 86 DWQ Sampling Analysis Plan Requirements .............................................................................................................. 86 Example Field Observation Form for Grab Samples ................................................................................................... 90 Appendix 2 ....................................................................................................................................................................... 91 Application of Secondary Review Process ........................................................................................................................ 91 Appendix 3 ....................................................................................................................................................................... 95 Summarizing Assessments From Site to Assessment Unit Level .................................................................................... 95 Appendix 4 ....................................................................................................................................................................... 99 4B Submission Policies and Procedures: Process for Determining Category 4B Classification ...................................... 99 Appendix 5 ..................................................................................................................................................................... 101 Delisting Guidelines ....................................................................................................................................................... 101 EPA Delisting Codes ...................................................................................................................................................... 102 Appendix 6 ..................................................................................................................................................................... 103 Response to Comments: 303(d) Assessment Methods ................................................................................................ 103 Daniel Lay .................................................................................................................................................................. 104 Rob Dubuc, Friends of Great Salt Lake ..................................................................................................................... 105 Grant Wilson, Earth Law Center ................................................................................................................................ 105 Shera Reems, EPA Region 8 .................................................................................................................................... 106 Ellen Bailey, DWQ ...................................................................................................................................................... 109 Ashley A. Peck, Wasatch Front Water Quality Council ............................................................................................. 109 David Richards, OreoHelix Ecological ....................................................................................................................... 110 5 Abbreviations Abbreviation Definition < less than > greater than ≤ less than or equal to ≥ greater than or equal to AGRC Automated Geographic Reference Center ATTAINS The Assessment, Total Maximum Daily Load, Tracking and Implementation System. This EPA- maintained database is an online system for accessing information about the conditions of the Nation’s surface waters. AU assessment unit Ca calcium CFR Code of Federal Regulations Chl-a chlorophyll a CWA Clean Water Act DEQ Utah Department of Environmental Quality DO dissolved oxygen DWQ Utah Division of Water Quality E expected E. coli Escherichia coli EPA U.S. Environmental Protection Agency 6 ER ecosystem respiration g grams GIS geographic information systems GPP gross primary productivity GSL Great Salt Lake GRAMA Government Records Access and Management Act HAB(s) harmful algal bloom(s) HH human health HUC hydrologic unit IR Integrated Report kg kilogram L liter Mg magnesium mg milligram mg/kg milligram per kilogram mg/L milligram per liter mL milliliter MLID monitoring location identifier MPN most probable number NHD National Hydrologic Dataset O observed O/E observed/expected 7 Pc probability of capturing ppm parts per million QA quality assurance QA/QC quality assurance/quality control QC quality control QAPP quality assurance project plan RIVPACS River Invertebrate Prediction and Classification System SAP(s) sample analysis plan(s) SD standard deviation SDD Secchi disk depth SOP(s) standard operating procedure(s) T temperature TDS total dissolved solids TMDL total maximum daily load TN total nitrogen TP total phosphorus TSI trophic state index UAC Utah Administrative Code UDOH Utah Department of Health USGS U.S. Geological Survey WMU watershed management unit WQP (EPA’s) Water Quality Portal 8 WQS water quality standard μg/L microgram per liter 9 Figures Figure 1. Utah's defined assessment units and assessment categories. ....................................................................... 14 Figure 2. Proportion and number of river, stream, and canal AU's in each assessment category. ................................ 15 Figure 3. Proportion and number of perennial river, stream, and canal miles in each assessment category. ............... 16 Figure 4. Proportion and number of river, stream, and canal AU impairments by parameter category. ......................... 16 Figure 5. Pie chart of river and stream impairments by use type. Note, some AU impairments are represented twice because parameters may be impaired for multiple uses. ................................................................................................ 17 Figure 6. Proportion and number of lake, reservoir, and pond AU's in each assessment category. .............................. 18 Figure 7. Proportion and number of lake, reservoir, and pond acres in each assessment category. ............................. 18 Figure 8. Proportion and number of lake, reservoir, and pond AU impairments by parameter category. ....................... 19 Figure 9. Pie chart of lake, reservoir, and pond impairments by use type. Note, some AU impairments are represented twice because parameters may be impaired for multiple uses. ...................................................................................... 19 Figure 10. Number of AU delistings by parameter type across all assessed waterbodies. ............................................ 20 Figure 11. Pie chart of delisting reasons across all assessed waterbodies. ................................................................... 21 Figure 12. Utah Division of Water Quality assessment unit delineations. ....................................................................... 23 Figure 13. Overview of the assessment process for conventional parameters using grab sample data. ....................... 36 Figure 14. Overview of the assessment process for the minimum dissolved oxygen, minimum, using high frequency data. ................................................................................................................................................................................. 37 Figure 15. Overview of the assessment process for the minimum dissolved oxygen, 7-day averages using high frequency data. ................................................................................................................................................................ 38 Figure 16. Overview of the assessment process for the minimum dissolved oxygen, 30-day averages, using high frequency data. ................................................................................................................................................................ 39 Figure 17. Overview of the assessment process to determine support of recreational life uses based on nutrient enrichment in headwater streams. .................................................................................................................................. 44 Figure 18. A hypothetical example of O/E as a standardization of biological assessments. .......................................... 45 Figure 19. Decision tree for making biological assessment decisions. ........................................................................... 46 Figure 20. Process using conventional (nontoxic) parameters to assess lakes that are mixed...................................... 49 Figure 21. Plots of pH measurements (blue dots) against lake depth for a waterbody meeting (Panel A) and violating (Panel B) the pH water quality standards. ....................................................................................................................... 50 Figure 22. Plots of temperature measurements (blue dots) against lake depth for two sites to provide an example of assessment procedures. Note: The red line illustrates a temperature criterion of 20 degrees Celsius: Class 3A beneficial use. .................................................................................................................................................................. 51 Figure 23. Beneficial use support based on the existence of adequate habitat. ............................................................. 52 Figure 24. Concept of the habitable zone where both DO and temperature are suitable for aquatic life. The site depicted on the top (Panel A) would be considered supporting because the lens where both temperature and DO provide sufficient habitat is greater than t ........................................................................................................................ 53 Figure 25. Assessment process to determine support of the agricultural beneficial use with TDS data. ....................... 54 Figure 26. Tier II assessment process for lakes, reservoirs, and ponds. ........................................................................ 55 Figure 27. Overview of the assessment process for toxic parameters. .......................................................................... 58 10 Tables Table 1. U.S. Environmental Protection Agency categorization of assessed surface waterbodies for Integrated Report purposes ........................................................................................................................................................ 12 Table 2. Subclassifications of Utah's beneficial uses ................................................................................................. 13 Table 3. DWQ's data-availability matrix ..................................................................................................................... 17 Table 4. Assessed waterbody types used for categorizing monitoring locations ........................................................ 21 Table 5. Data validation criteria for water quality field grab sample parameters ......................................................... 27 Table 6. Data validation criteria for water quality high frequency dissolved oxygen data. .......................................... 28 Table 7. Data validation criteria for water quality chemistry grab sample parameters ................................................ 29 Table 8. Data validation criteria for macroinvertebrate data. ...................................................................................... 30 Table 9. Data validation criteria for Escherichia coli (E. coli) data. ............................................................................ 31 Table 10. Summary of data types considered by Utah’s IR program ........................................................................ 32 Table 11. Conventional parameters and associated designated uses as identified for assessment purposes ........... 34 Table 12. Numeric Nutrient Criteria and Associated Ecological Responses (Bioconfirmation Criteria) to Protect Aquatic Life Uses in Antidegradation Category 1 and 2 (UAC R317-2-12) Headwater Perennial Streams ........... 42 Table 13. Decision Matrix That Will Be Used to Assess Support of Headwater Aquatic Life Uses for Nutrient- related Water Quality Problems ................................................................................................................................. 43 Table 14. Beneficial use support determination for O/E values obtained from different sample sizes ........................ 47 Table 15. Selenium trigger levels and DWQ responses (UAC R317-2-14.2(14)) ....................................................... 56 Table 16. Cyanotoxin thresholds for recreational use assessments based on EPA (2019) guidance ................... 66 Table 17. Application of secondary review process………………………………………………………………………91 Table 18. Description of EPA Delisting Codes. ………………………………………………………………………...102 11 Executive Summary Purpose Section 305(b) of the Clean Water Act (CWA) requires states to submit a biennial report to the Environmental Protection Agency (EPA) on the quality of their waters. The 2024 Integrated Report (IR) prepared by the Utah Division of Water Quality (DWQ) to meet this federal requirement is a comprehensive analysis of the condition of the state‘s rivers, streams, canals, lakes, reservoirs, and ponds. Section 303(d) of the CWA requires states to submit a list of waterbodies that do not meet the state‘s water quality standards as part of the IR. This list guides the state‘s development of water quality improvement plans (Total Maximum Daily Load plans or TMDLs) for impaired waterbodies to bring them into compliance with their beneficial uses and water quality standards. The IR supports DWQ‘s commitment to protecting and improving the water quality of Utah‘s rivers, streams, canals, lakes, reservoirs, and ponds by providing critical information and thorough analyses of water quality conditions, waterbody impairments, statewide trends, and emerging issues. DWQ uses these data to identify areas with impairments and prioritize projects, TMDLs, and best management practices (BMPs) to improve and enhance water quality in affected areas. Scope The 2024 IR reports on 918 assessment units (AUs), over fifteen thousand perennial miles of rivers, streams, and canals, and nearly 1.5 million lake, reservoir, and pond acres. The water quality assessment data covers the period between October 1, 2016 and September 30, 2022 and includes updates from previous reports. The data used in the report were collected by DWQ, 9 agencies, and numerous public and private stakeholder groups and individuals. Methods The State of Utah sets water quality standards that support designated beneficial uses for Utah‘s rivers, streams, canals, lakes, reservoirs, and ponds. These designations protect water quality for different uses, including drinking water, recreation, aquatic life, and agriculture. Waterbodies are protected for several combinations of beneficial uses, such as recreation and aquatic life. Data Collection The IR uses water quality data collected by DWQ and a number of public and private entities to determine whether assessed waterbodies in the state meet water quality standards and support their designated beneficial uses. Data submitted or obtained by DWQ during the IR data compilation process are integrated into DWQ‘s assessments and subject to DWQ‘s data management and quality assurance and quality control (QA/QC) processes. Datasets may include laboratory results for water chemistry sampling for conventional (e.g., temperature) and toxic (e.g., metals) parameters, monitoring data specific to lakes, reservoirs, ponds, or flowing surface waters, potential 12 causes of impairments, and macroinvertebrate surveys. DWQ combines data from individual monitoring sites into a larger spatial scale or Assessment Unit (AU). The Division collects all readily available and credible water quality data for each AU and prepares the data for assessment. Data are assessed according to specific conventional and toxic parameters against beneficial use criteria established in state regulations. DWQ uses these data to categorize the state‘s assessment units to determine designated beneficial use attainment. The state uses five EPA-approved categories in its assessment determinations: • Category 1: All beneficial uses attained. • Category 2: Some beneficial uses attained but there are insufficient data to determine if all beneficial uses are supported. • Category 3: Insufficient or no data to make a determination. • Category 4: Impaired for one or more beneficial uses. Does not require the development of a TMDL because one has already been completed (4A), uses are expected to be attained within a reasonable timeframe (4B), or the impairment is not caused by a pollutant (4C). • Category 5: Impaired for one or more beneficial uses by a pollutant. Requires the development of a TMDL. Waters determined to be impaired are placed on the state‘s 303(d) list and prioritized for TMDL development. The TMDLs calculate the pollution reduction levels needed to support designated beneficial uses and meet water quality standards. Once a TMDL is completed and approved by EPA, the assessment unit covered under the TMDL is transferred from Category 5 (impaired) to Category 4A (approved TMDL in place). Delistings DWQ reviews the data submitted during the IR process to determine whether assessment units identified as impaired in previous IRs are now meeting their designated beneficial uses. If DWQ finds during its assessment that waterbodies previously listed as impaired are now meeting water quality standards, it provides a list of the sites proposed for removal from the 303(d) list (Category 5) in the report. DWQ can delist a previously impaired parameter, waterbody, or segment within a waterbody that is currently meeting water quality standards if it can demonstrate good cause to stakeholders and EPA. Good cause includes one or more of the following: • The impairment was resolved through the implementation of nonpoint source projects and/or revised effluent limits. • Revised water quality standards and/or beneficial uses put the waterbody into attainment of those standards and/or uses. • A new listing method consistent with state water quality standards and classifications and federal listing requirements changed the previous listing. • New data led to a reassessment that demonstrated that applicable standards and uses are being met. • Flaws in the original analysis led to an incorrect listing. • Improved modeling applications demonstrated that applicable standards and uses are being met. AU Resegmentation When site-specific assessments within a single AU conflict, DWQ may determine that it is appropriate to resegment (i.e. “split”) an existing AU polygon into two or more new AUs rather than aggregate those conflicting assessments into a single AU scale category. AUs where water quality criterion exceedances are clearly isolated 13 to a relatively small, hydrologically distinct portion of the larger AU may be re-segmented to more accurately reflect that variation in water quality. This results in a higher resolution and overall more accurate assessment. DWQ does not consider it appropriate to re-segment an AU when exceedances are observed in multiple locations throughout an AU, or where impaired sites are not hydrologically distinct from unimpaired portions of the AU. Public Comment Process DWQ engages its stakeholders early in the process as part of its ongoing commitment to work with the public to safeguard human health and protect and enhance Utah‘s waters. Communities and others affected by the decisions under CWA 305(b) and 303(d) are asked to participate in the IR process during three public involvement opportunities before the Division submits the IR to EPA. 1. Public Comment on Assessment Methods DWQ held a public comment period on the 303(d) Assessment Methods from October 24, 2022, to December 8, 2022, to solicit public input on the assessment methods for the 2024 IR. DWQ received comments from seven different individuals and groups for a combined total of approximately 28 unique comments. DWQ’s Response to Comments, as well as the comments submitted, can be found on the Integrated Report Program webpage. 2. Publicly Submitted Data Notification DWQ issues a formal public notification during each IR cycle through website postings and listservs requesting data and information that can be used for the assessment. Whenever possible, DWQ tries to obtain all data and information with sufficient time to compile the information during odd-numbered years. This provides the Division with adequate time to obtain clarification where necessary and ensures that outside sources of information are used to the greatest extent possible for IR assessments. The 2024 IR Call for Data ran for 30 days from March 28,2023 to April 28, 2023. Data submitters registered on the DWQ Call for Data website and were provided detailed instructions on how to submit data accurately and effectively to EPA’s Water Quality Exchange. 3. Public Comment on 305(b) and 303(d) Decisions DWQ provides another formal public notification at the end of the IR report writing process, requesting comments on the placement of AUs in the five categories. DWQ responds to the comments in a summary and can revise the IR based on the public’s feedback. Public comments and DWQ’s response are then submitted to EPA along with the 305(b) report and 303(d) listing decisions. Findings DWQ compiled all existing and readily available data and conducted designated beneficial use assessments to determine which waters in the state are supporting or not supporting these uses. The figures, charts, and graphs below offer a view of the state‘s perennial waterbody miles and acreage, areas and water quality parameters assessed, and waterbodies proposed for delisting. 14 Figure 1. Utah's defined assessment units and assessment categories. Assessment Totals • Total AUs reported on: 918 • Total AUs fully supporting (Category 1): 103 • Total AUs with no evidence of impairment (Category 2): 184 • Total AUs with insufficient data (Category 3): 216 • Total AUs with a TMDL in place (Category 4A): 27 • Total AUs requiring a TMDL (Category 5): 388 • Number of data records assessed: 548,569 discrete samples, 2.4 million high frequency dissolved oxygen measurements 15 River, Stream and Canal Assessments Assessments • Total AUs reported on: 775 • Total perennial miles reported on: 15,820 • Total monitoring locations assessed and reported on during the period of record: 1,731 In 2024, 29% of assessment units (AUs) and 31% of perennial stream miles were supporting their designated beneficial uses or had no evidence of impairments (Figure 2, Figure 3). Conversely, the 222 AUs (27% of AUs) with insufficient data to make an assessment generally represent fewer than average perennial stream miles. River, stream, and canal AUs are most commonly impaired for dissolved oxygen, pH, and temperature, which make up 42% of 303(d) listings (Figure 4). A majority of these impairments indicate that the waterbody is not meeting its aquatic life beneficial use(s) (Figure 5). Figure 2. Proportion and number of river, stream, and canal AU's in each assessment category. 16 Figure 3. Proportion and number of perennial river, stream, and canal miles in each assessment category. Figure 4. Proportion and number of river, stream, and canal AU impairments by parameter category. 17 Figure 5. Pie chart of river and stream impairments by use type. Note, some AU impairments are represented twice because parameters may be impaired for multiple uses. Lake, Reservoir, and Pond Assessments Assessments • Total AUs reported on: 143 • Total lake acres reported on: 1.47 million (includes Great Salt Lake at 1.1 million acres) In lake, reservoir, and pond assessments, large discrepancies in the acreage represented by AUs led to striking differences in the percentage of AUs and acres in each assessment category. While 65% of AUs are not supporting one or more beneficial uses, that accounts for only 10% of total lake acres assessed (Figure 6, Figure 7). This is due to the overwhelming representation of the Great Salt Lake in acreage calculations. Additionally, 45% of AUs and 53% of total lake acres assessed are either fully supporting all designated uses or show no evidence of impairment. Similar to rivers and streams, a majority of impairments are linked to dissolved oxygen, pH, or temperature (Figure 8). The vast majority of impairments indicate that the waterbody is not meeting its aquatic life beneficial use(s) (Figure 9). 18 Figure 6. Proportion and number of lake, reservoir, and pond AU's in each assessment category. Figure 7. Proportion and number of lake, reservoir, and pond acres in each assessment category. 19 Figure 8. Proportion and number of lake, reservoir, and pond AU impairments by parameter category. Figure 9. Pie chart of lake, reservoir, and pond impairments by use type. Note, some AU impairments are represented twice because parameters may be impaired for multiple uses. 20 Delistings 49 river and stream AUs were delisted for one or more parameters. Five lake and reservoir AUs were delisted for one or more parameters. Figure 10. Number of delistings by parameter type across all assessed waterbodies. Some AUs have multiple parameters that were delisted. 21 Figure 11. Pie chart of delisting reasons across all assessed waterbodies. Recommendations Priority Waters The CWA requires the development of total maximum daily load (TMDL) plans for all impaired waterbodies on the 303(d) List but recognizes the limitations in data, time, and staff resources to accomplish this task. Taking these limitations into account, the CWA requires states to prioritize where they will dedicate resources toward TMDL development. From 2013-2023, DWQ prioritized water quality impairments that posed the greatest risk to human health as described in Utah's 303(d) Vision. These priorities focused on the protection and restoration of waters designated for culinary and recreational uses by focusing on pathogen impairments. This resulted in approved E. coli TMDLs for the North Fork Virgin River, Fremont River, Spring Creek in Heber, and the Jordan River watershed (14 subwatersheds). In September 2022, EPA released the next iteration of the CWA Section 303(d) Vision that requires states to submit updated water quality priorities and goals to EPA by April 2024. Vision 2.0 includes the original programmatic goals with opportunities for protection and restoration of waters through planning and prioritization, restoration, protection, data and analysis, and partnerships. When program goal setting, states must also consider environmental justice, climate change, tribal water quality, program development and capacity building. Utah's approach to water quality restoration planning for the next ten years will be determined through the use of EPA's Recovery Potential Screening (RPS) tool and a widely-distributed public survey on the uses and threats to Utah’s waters. The Utah Vision 2.0 Approach Framework will be submitted to EPA in April, 2024 and the prioritized list for water quality restoration plans (e.g.,TMDLs, Nine Element Watershed Plans, and Advance Restoration Plans) will be submitted to EPA in September, 2024. 22 Chapter 1 303(d) Assessment Methods Introduction The Clean Water Act and the Integrated Report The rules and regulations of the federal Clean Water Act (CWA) require the Utah Division of Water Quality (DWQ) to report the condition or health of all Utah surface waters to the U.S. Congress every other year. The Integrated Report (IR) contains two key reporting elements defined by the CWA: Statewide reporting under CWA Section 305(b): Section 305(b) reporting summarizes the overall condition of Utah’s surface waters as well as key water quality concerns. These concerns can include pollutants, habitat alteration, and sources of water quality problems. Water quality assessments under CWA Section 303(d): Section 303(d) requires states to identify waters that are not supporting beneficial uses according to state water quality standards (Utah Administrative Code [UAC] R317-2-7.1). Utah’s Section 303(d) list (hereafter the 303(d) list) also prioritizes the total maximum daily loads (TMDL) required for each listed waterbody and the cause of nonattainment. This list includes waters impaired as a result of nonpoint sources, point source discharges, natural sources, or a combination of sources. In addition to Utah’s 303(d) list, DWQ also identifies • Waterbodies meeting water quality standards • Waterbodies with water quality problems that DWQ cannot confirm due to insufficient sample size, uncertainty regarding the nature of the data or other factors • Waterbodies either currently addressed by DWQ through a TMDL or other pollution-control mechanism Full descriptions of these and other U.S. Environmental Protection Agency (EPA)-identified waterbody assessment classifications are described and summarized in Table 1 . Assessment Categories for Surface Waters DWQ uses five categories defined by EPA to assess surface waters of the state (EPA, 2005). These categories are described in Table 1. 12 Table 1. U.S. Environmental Protection Agency categorization of assessed surface waterbodies for Integrated Report purposes. EPA Assessment Category Assessment Category Description 1 Supporting. All beneficial uses assigned to a waterbody are evaluated against one or more numeric criteria and each use is found to meet applicable water quality standards. 2 No Evidence of Impairment. Some, but not all, beneficial uses assigned to a waterbody are evaluated against one or more numeric criteria, and each assessed use is found to meet applicable water quality standards. 3 Insufficient Data and/or Information. There are insufficient data and information to conclude support or nonsupport of a use. The category may be applied when: (1) the dataset is smaller in size and has water quality criteria exceedances OR no water quality criteria exceedances; (2) a secondary review applied to a waterbody found it was not meeting water quality standards; (3) water quality criteria and/or beneficial use support assessment methods are not yet developed (or are undergoing development or revisions) so use attainment has not been determined; (4) waterbodies were assessed against water quality parameters and characteristics that require further investigations as defined in UAC R317-2; (5) assessment units (AUs) have improper use designations, lack use designations, or contain other inconsistencies in the dataset. In cases where no recent data are available, historic-listing determinations will be maintained. 4A TMDL-Approved. Waterbodies impaired by a pollutant with a TMDL(s) developed and approved by EPA. Where more than one pollutant is associated with the impairment, the waterbody and the parameters that have an approved TMDL are listed in this category. If a waterbody has other pollutants that need a TMDL, the waterbody is listed in Category 5 with an Approved TMDL. 4B Pollution Control. Waterbodies that are not supporting designated uses where other pollution-control requirements, such as best management practices required by local, state, or federal authority, are stringent enough to bring the waters listed in this category back into attainment in the near future with the approved pollution-control requirements in place, consistent with 40 Code of Federal Regulations (CFR) 130.7(b) (I) (ii) and (iii). All waterbodies placed in this category must have a pollution control requirement plan developed and approved by EPA. Similar to Category 4A, if the waterbody has other pollutants that need a TMDL, or there is already a TMDL in place for another pollutant, the waterbody may also be listed in Categories 5 and 4A. Therefore, an AU with a pollution control in place may be listed in Categories 4B, 4A, and 5. 4C Non-Pollutant Impairment. Waterbodies not supporting designated uses are placed in this category if the impairment is not caused by a pollutant but rather by pollution (for example, hydrologic modification or habitat degradation). Similar to Categories 4A and 4B, if the waterbody has other pollutants that need a TMDL, or there is an approved TMDL or pollution-control mechanism in place, the waterbody may also be listed in Categories 4A, 4B, and 5. Therefore, an AU with a pollution control in place may be listed in Categories 4C, 4B, 4A, and 5. 5 Not Supporting. The concentration of a pollutant or several pollutants exceeds numeric water quality criteria, or beneficial uses are not-supporting based on violation of the narrative water quality standards. Waterbodies identified as “threatened” may also be placed in this category. In a “threatened” waterbody, one or more of its uses are likely to become impaired by the next IR cycle and water quality may be exhibiting a deteriorating trend if pollution control actions are not taken. Both impaired and threatened waterbodies constitute Utah’s formal Section 303(d) list and are prioritized for future TMDL development. 5-Alt TMDL Alternatives. The 303(d) program vision promotes the identification of alternative approaches to TMDL development for impaired waters where these approaches would result in a more rapid attainment of water quality standards. Note: This category is referenced in DWQ’s “303(d) Vision Document.” 13 Utah’s Numeric Criteria and Beneficial Uses DWQ assesses the impacts of measured pollutant concentrations on environmental and human health to determine the appropriate assessment categories for a waterbody (see Table 1 ). Utah has developed and adopted water quality numeric criteria (chemical concentrations that should not be exceeded) to protect the water quality of surface waters and the uses these waterbodies support (UAC R317-2-14). As noted in UAC R317-2-14, the water quality criteria for a pollutant can vary depending on the beneficial use assigned to a waterbody. Utah adopted beneficial use classifications that identify the use and value of a waterbody for source water for domestic water systems, aquatic wildlife, recreation, agriculture, and Great Salt Lake (see UAC R317-2-6). DWQ currently designates five beneficial use classes of surface waters within the state: • Class 1. Protected for use as a raw water source for domestic water systems • Class 2. Protected for recreational use and aesthetics • Class 3. Protected for use by aquatic wildlife • Class 4. Protected for agricultural uses including irrigation of crops and stock watering • Class 5. The Great Salt Lake (GSL) Subclassifications for several of these categories are further defined in Table 2. Table 2. Subclassifications of Utah's beneficial uses. Beneficial Use Subclassification Use Definition 1C* Protected for domestic purposes with prior treatment by treatment processes as required by the Utah Division of Drinking Water 2A Protected for frequent primary contact recreation where there is a high likelihood of ingestion of water or a high degree of bodily contact with the water. Examples include, but are not limited to, swimming, rafting, kayaking, diving, and water skiing. 2B Protected for infrequent primary contact recreation. Also protected for secondary contact recreation where there is a low likelihood of ingestion of water or a low degree of bodily contact with the water. Examples include, but are not limited to, wading, hunting, and fishing. 3A* Protected for cold water species of game fish and other cold water aquatic life, including the necessary aquatic organisms in their food chain. 3B* Protected for warm water species of game fish and other warm water aquatic life, including the necessary aquatic organisms in their food chain. 3C* Protected for nongame fish and other aquatic life, including the necessary aquatic organisms in their food chain. 3D* Protected for waterfowl, shore birds and other water-oriented wildlife not included in Classes 3A, 3B, or 3C, including the necessary aquatic organisms in their food chain. 3E* Severely habitat-limited waters. Narrative standards will be applied to protect these waters for aquatic wildlife. 4 Protected for agricultural uses including irrigation of crops and stock watering. 5A Gilbert Bay Geographical Boundary: All open waters at or below approximately 4,208-foot elevation south of the Union Pacific Causeway, excluding all of the Farmington Bay south of the Antelope Island Causeway and salt evaporation ponds. Beneficial Uses: Protected for frequent primary and secondary contact recreation, waterfowl, shore birds and other water-oriented wildlife including their necessary food chain. 14 Beneficial Use Subclassification Use Definition 5B Gunnison Bay Geographical Boundary: All open waters at or below approximately 4,208-foot elevation north of the Union Pacific Causeway and west of the Promontory Mountains, excluding salt evaporation ponds. Beneficial Uses: Protected for infrequent primary and secondary contact recreation, waterfowl, shore birds and other water-oriented wildlife including their necessary food chain. 5C Bear River Bay Geographical Boundary: All open waters at or below approximately 4,208-foot elevation north of the Union Pacific Causeway and east of the Promontory Mountains, excluding salt evaporation ponds. Beneficial Uses: Protected for infrequent primary and secondary contact recreation, waterfowl, shore birds and other water-oriented wildlife including their necessary food chain 5D Farmington Bay Geographical Boundary: All open waters at or below approximately 4,208-foot elevation east of Antelope Island and south of the Antelope Island Causeway, excluding salt evaporation ponds. Beneficial Uses: Protected for infrequent primary and secondary contact recreation, waterfowl, shore birds and other water-oriented wildlife including their necessary food chain. 5E Transitional Waters along the Shoreline of the Great Salt Lake Geographical Boundary: All waters below approximately 4,208-foot elevation to the current lake elevation of the open water of the Great Salt Lake receiving their source water from naturally occurring springs and streams, impounded wetlands, or facilities requiring a UPDES permit. The geographical areas of these transitional waters change corresponding to the fluctuation of open water elevation. Beneficial Uses: Protected for infrequent primary and secondary contact recreation, waterfowl, shore birds and other water-oriented wildlife including their necessary food chain. *Footnote: There are human health (HH) criteria associated with these beneficial uses (see UAC R317-2- 14). For uses with a HH criteria, (see Table 2.14.6 in UAC R317-2-14), the following use notation will be used in 303(d) data and assessment reports: HH1C, HH3A, HH3B, HH3C, and HH3D. Every beneficial use with numeric criteria and credible and readily available data is assessed and reported for 303(d) assessment purposes. DWQ does not just assess and report on the most environmentally protective criterion and/or use for a parameter and waterbody. Where waterbodies are unclassified and do not have assigned beneficial uses in DWQ data records, DWQ may assign default beneficial uses as articulated in UAC R317-2-13.9,13.10,13.11,13.12, and 13.13. Alternately, these undefined waterbodies may be classified as an EPA Assessment Category 3 or not reported in the IR if an Assessment Unit has not been established. For more information on how DWQ develops, adopts, and updates the numeric criteria and beneficial uses in UAC R317-2, please refer to DWQ’s Standards website. Assessed Parameters Water quality assessments may not report on all parameters listed in UAC R317-2-14. Assessments reflect parameters with adopted numeric criteria that also have readily available and credible datasets from the period of record. Monitoring and data availability for pollutants listed in UAC R317-2-14 may be constrained by: • Laboratory resources that limit the ability to assess all parameters in UAC R317-2-14 • Significant monitoring and/or analytical costs associated with processing a sample or measuring a pollutant • Logistical constraints due to monitoring location and holding times for certain parameters 15 Assessment Process and Time Frames Developing the Methods This document describes the most up-to-date assessment methods that will be applied to Utah’s current IR cycle. Although most of the methods described have been applied in past assessment cycles, other methods are new or modified from previous reporting cycles. Some of the assessment method revisions are intended to clarify ongoing DWQ practices. Other more substantive revisions may be based on comments that were raised during the previous IR’s 303(d) assessment methods and draft IR public comment periods. DWQ updates and revises the 303(d) methods when concerns are raised or when program developments are released by DWQ. Additional modifications or clarifications to the assessment methods may also be made based on feedback provided by EPA during and after a reporting cycle or from the EPA’s cycle-specific 303(d) guidance memorandum. All changes made to the 303(d) assessment methods are typically reviewed and updated on even-numbered years in anticipation of developing the Draft IR and 303(d) list in the following odd-numbered year. This process allows DWQ to consider comments and suggestions on assessment methods before a formal analysis is conducted. This reduces the need to rework analyses from changes in methods. Public Review of the Methods Process and Schedule The development and acceptance of the Assessment Methods includes a public review process and occurs on the following schedule: a. DWQ releases the proposed Assessment Methods for a 30-day public comment period. The notice for public comments on the Assessment Methods are advertised on DWQ’s News and Announcements webpage, DWQ’s Public Notices webpage, and Utah’s Integrated Report program webpages. b. DWQ compiles and responds to the comments received within the 30-day public comment period. DWQ’s responses to comments are posted on the Utah’s Integrated Report program webpages. c. If substantial revisions to the Assessment Methods are adopted by DWQ based on comments received in the public comment period, DWQ has the discretion to hold a second public comment period of 30 days or less. Should DWQ proceed with a second public comment period, notifications will be advertised, at a minimum, on DWQ’s News and Announcements and/or Public Notices webpages, and the Utah’s Integrated Report program webpages. d. Following the conclusion of the public comment period(s), DWQ posts responses to comments on the Utah’s Integrated Report program webpages. Any changes or additions that were made in response to public comments will be documented and issued with the draft IR and 303(d) list. During the draft IR public comment period, comments on the Assessment Methods are considered out of scope unless otherwise indicated. Concerns and comments not received through the above processes may not be considered for current and future 303(d) methods, updates and modifications. Call for Readily Available Data and Schedule DWQ issues a request for all readily available data (i.e., the IR Call for Data) after November 1 of even- numbered years. 16 Existing and Readily Available Data Defined DWQ assembles and evaluates all existing and readily available data to determine whether a waterbody is supporting or not supporting the assigned beneficial uses and numeric criteria in UAC R317-2 as mandated in 40 CFR 130.7(b)(5). For the purposes of the IR, existing and readily available data may include: • Data and information referenced in 40 CFR 130.7(b)(5)(i),(iii), and (iv) • Data collected by DWQ or DWQ cooperators for assessment purposes • Data collected for other DWQ programs, such as waste load allocations, TMDL development, watershed planning, and use attainability analyses • Data collected for narrative assessments (see Narrative Assessment: Biological Assessments and Narrative Standards for All Waters) • Data obtained through EPA’s Water Quality Portal (WQP) • Data and information obtained through the IR’s public Call for Data • Data and information submitted to EPA’s Water Quality Exchange System or DWQ’s Call for Data to support a credible data submission (e.g., Table 5-8) • Data included in the Data Types Matrix in Table 10 Data and information (as described above) that are not brought forward during the IR’s Call for Data or presented to DWQ in accordance with the schedule as outlined in this document and on Utah’s Integrated Report program webpages will not be treated as readily available for the purpose of assessment decisions during the current assessment cycle. Data that are submitted to DWQ or obtained by DWQ during the IR data compilation process are integrated into DWQ’s assessments as described in Table 3 and subject to DWQ’s data management and quality assurance/quality control (QA/QC) processes. Should any data and information not be included in the assessment process, DWQ will clearly document which dataset (or datasets) were not included and why (as described and required in 40 CFR 130.7(b)(6)(iii) 17 Table 3. DWQ's data-availability matrix. Data Availability Description Processing required Uses for Assessments Readily available Data are incorporated into EPA’s WQP database and can interface directly with DWQ’s IR data processing and assessment tools. Data is submitted by stakeholders or data submitters through DWQ’s data submission templates or electronic submission processes which are provided on the Call for Data webpage.1,2 None Fully incorporate into DWQ’s assessment tools Additional “other” sources of data included in the Data Types Matrix in Table 10 that described the waterbodies in 40 CFR 130.7(b)(5)(i), (iii), and (iv) and are submitted through DWQ’s electronic submission process as described on the Call for Data webpage. None Fully incorporate into DWQ’s Conflicting Assessments of Water Quality Standards and Secondary Review processes Readily available (additional processing may be required by DWQ) Quantitative data and information may be stored in and routinely uploaded to a queryable, regularly maintained database that is available on the web or electronically submitted to DWQ during the public call for data. Database format is consistent and allows repeatable queries with predictable results (e.g., parameter names, location descriptions, and parameter units are consistent), making development of automated interface tools practicable. Full incorporation into IR assessment tools requires DWQ development of interface tools for aggregating, translating, and harmonizing data to appropriate formats. In particular, sampling locations and dates, parameter names, fractions, units, analysis methods, and detection limits require translation and interpretation prior to assessment. Fully incorporate into IR assessment tools if interface tools have been developed.2 If interface tools are still in the development phase, (1) screen data for exceedances for the waterbodies described in 40 CFR 130.7(b)(5)(i), (iii), and (iv), or (2) manually assess data for specific sites, dates, and parameters at the request of stakeholders or data submitters for waterbodies described in 40 CFR 130.7(b)(5)(i), (iii), and (iv). Results are fully incorporated into DWQ’s Conflicting Assessments of Water Quality Standards and Secondary Review. 1 DWQ data submission templates and processes are designed to allow for data and information that may not fit the data structure of EPA’s Water Quality Exchange System. They may also be used to support a credible data review (Tables 5-8) or perform narrative or high frequency data assessments. 2 DWQ requests data submitters inform the Division which data system contains their data so DWQ can work with submitters prior to the IR’s Call for Data to develop interface tools. 18 Developing the Components of the Draft Integrated Report and 303(d) List DWQ reviews all data and assigns a credible data “grade” following its response to public comments on the draft 303(d) Assessment Methods and compilation of all existing and readily available data. All non-rejected, credible data are then assessed. The final 303(d) Assessment Methods, 305(b) Summary, and 303(d) List of Impaired Waters are the minimum reporting elements included in the Integrated Report. These reporting elements are available for public review and comment. Final 303(d) Assessment Methods The final version of the publicly-vetted 303(d) Assessment Methods, including any changes or additions made in response to the Assessment Method public comment period(s) is posted on the Utah’s Integrated Report program webpages. 305(b) Summary This summary, at a minimum, will address the following elements for previous and new or updated assessments: • A unique identifier assigned to the Assessment Unit • The name and location description of the Assessment Unit • An indicator of whether the Assessment Unit is currently active, or if the Assessment Unit identifier was retired and being kept for historical tracking purposes and is part of an Assessment Unit history of another Assessment Unit • The waterbody type for the Assessment Unit • The size and the unit of measure for the assessed waterbody type • The EPA-defined assessment category for each defined and evaluated Assessment Unit 303(d) Assessment Results At a minimum, the following information will be provided for previous and new or updated assessments: • The minimum elements discussed above in the 305(b) Summary • The cycle the Assessment Unit was last assessed, which can include any conclusions related to this Assessment Unit and delisting decisions (if appropriate) • The beneficial use(s) designated to the Assessment Unit and the EPA-defined assessment categories associated with the beneficial use after assessment • The name of the parameter assessed, the beneficial use associated with the assessed parameter, and the EPA-defined assessment category status for the parameter and beneficial use • A flag indicating whether or not the cause of the attainment status is a pollutant • The IR cycle the Assessment Unit was first listed for a cause • The reason(s) for identifying the delisting of a waterbody 305(b) Summary and 303(d) Assessment Metadata DWQ will provide (at a minimum) the following supporting information and documentation as referenced in CFR 130.7 (b)(6) to support its decision to list or not list waters: • A description of, and access to, the data records and information used in the IR’s current period of record 19 • A rationale for, and access to, any data and information that was obtained or submitted to DWQ during the call for data but did not meet DWQ’s readily available or credible data requirements and was not used for 305(b) and 303(d) assessments • A rationale for, and access to, any rejected data records and information For archiving purposes and to assist with the review of the IR and 303(d) List, DWQ will also provide the following as time and resources allow: • The assessment method type and the assessment method context as defined in ATTAINS • Geolocation information on the waterbodies assessed • The date and version of UAC R317-2 used in the assessment cycle • The list of approved TMDLs used in the assessment cycle • An executive summary of the Final IR results Note: In odd-numbered years, DWQ will “freeze” and establish file versions of several working files to maintain consistency and data integrity. These files include geographic information system (GIS) point files of monitoring locations, layers of AUs, beneficial uses, and water quality standards. Public Review of the 303(d) List There will be a formal public review process for the IR and 303(d) list using the following steps: a. Any person who has a pollution-control mechanism plan for a waterbody and would like to submit that plan for consideration and EPA approval as a Category 4B must submit that information to DWQ by July 1 of even-numbered years (Appendix 4). If approved by DWQ, this information will then be submitted to EPA for review and final approval. It should be noted, however, that it takes a long time for successful Category 4B determinations to receive EPA approval and they may not be received in time to be included in the current IR cycle. b. Waters and pollutants that are considered for a potential Category 4A (approved TMDLs) must be approved by DWQ’s Water Quality Board per UAC R317-1-7 and by EPA per 40 CFR 130.7 by July 1 of odd-numbered years. TMDLs that are approved by DWQ and EPA after that date will be considered in future IRs. c. DWQ will release the proposed IR and 303(d) list for a 30-day public comment period after July 1 of odd-numbered years and no later than February 1 of even-numbered years. At a minimum, the notice for public comments on the IR will be advertised on DWQ’s News and Announcements and/or Public Notices webpages, and the Utah’s Integrated Report program webpages. d. Stakeholders who wish to submit data for listing or delisting considerations are encouraged to submit that data and information during the Utah’s IR program’s Call for Data. However, DWQ may consider data that are submitted during the public comment period of the draft IR and 303(d) list when the commenter can show that submitted data could result in a change to a specific waterbody assessment decision. Data that are submitted during the public comment period for the draft IR must be submitted in the format articulated in this document and on the IR Call for Data website and be of Grade A or B quality to be used in an assessment decision (see Tables 5- 9). Information submitted during the public comment period will undergo a secondary review (see Secondary Review and Appendix 2). e. DWQ will compile and respond to comments that were received within the 30-day public comment period after the close of the public comment period. f. DWQ may offer a second public comment period of 30 days or fewer if substantial revisions to the IR and 303(d) list are adopted on the basis of comments received during the first public comment period. Should DWQ proceed with a second public comment period, notifications will be advertised, at a minimum, on DWQ’s News and Announcements and/or Public Notices webpages, and the Utah’s Integrated Report program webpages. g. DWQ will submit a response to the public comments that were received during the 30-day public comment period and a final version of the IR and 303(d) list to EPA for final approval no later than April 1 of even-numbered years. DWQ will post a status update on the Utah’s Integrated Report 20 program’s webpages to let stakeholders know that a final IR was submitted to EPA for final approval. Any concerns or rebuttals from stakeholders regarding the IR will not be considered for the recently submitted IR after the submission of the IR to EPA for final approval. If stakeholders continue to have concerns with the IR and 303(d) list, they should submit their comments during the next IR cycle. h. EPA has 30 days to approve or disapprove the 303(d) list after receiving DWQ’s formal submission letter, IR chapters, 303(d) list, categorization of non-303(d) waterbodies, public comments received and DWQ’s response to them, delisting tables and justifications, list of approved TMDLs/pollution-control mechanisms, and GIS files of all assessment results. If EPA disapproves a state 303(d) list, EPA has 30 days to develop a new list for the state, although historically EPA has rarely established an entire list for a state. EPA may also partially disapprove a list because some waters have been omitted, and EPA may add these waters to the state’s list. If EPA’s final approval of the IR takes longer than the timeframe identified above, DWQ will post updates on Utah’s Integrated Report programs webpages. i. Any concerns and comments not received by DWQ through the above processes will not be addressed in the IR. Finalizing the Integrated Report and 303(d) List DWQ will release the following information on the Utah’s Integrated Report program webpages following approval by EPA: • A final version of 303(d) Assessment Methods, including the public comments received and DWQ’s response to comments • Final IR chapters and 303(d) lists, including public comments received, DWQ’s response to comments, all assessment information considered and evaluated in the finalization of the IR and 303(d) list, and a GIS file of the final assessments and 303(d) list EPA maintains a database of state IR results and TMDL status. Additional information not available on Utah’s Integrated Report program’s webpages may be obtained through a Government Records Access and Management Act request. These requests can be submitted at any time. Scope of the Assessment Waters of the State As defined in UAC R317-1-1, DWQ characterizes waters of the state as follows: … all streams, lakes, ponds, marshes, watercourses, waterways, wells, springs, irrigation systems, drainage systems, and all other bodies or accumulations of water, surface and underground, natural or artificial, public or private, which are contained within, flow through, or border upon this state or any portion thereof, except that bodies of water confined to and retained within the limits of private property, and which do not develop into or constitute a nuisance, or a public health hazard, or a menace to fish and wildlife, shall not be considered to be "waters of the state" under this definition (Section 19-5-102). For 303(d) assessment purposes, DWQ reports on the following waterbodies: • Rivers and streams • Canals as identified in site-specific standards or named in the list of waters with designated use classifications in UAC R317-2 • Lakes, reservoirs, and ponds 21 All other waters are currently reported through other programs within DWQ. For more information on these waterbodies and their reports, please visit DWQ’s website. Waterbody Types Utah assesses surface waters of the state at the monitoring-site level and then summarizes the site-level assessments at a larger spatial scale (the Assessment Unit (AU) scale). DWQ uses the descriptions in Table 4 to determine appropriate assessment sites and categorize monitoring locations. Table 4. Assessed waterbody types used for categorizing monitoring locations. Assessed Waterbody Type Description Rivers and streams* Perennial and intermittent surface waters are included in this type. Springs and seeps are also included in this waterbody type, provided they are flowing and connect, contribute, or are influencing water quality in a downstream river or stream. Canals (general, irrigation, transport, or drainage)* A human-made water conveyance with flowing water. Note: Canals are only assessed when identified in the site-specific numeric criteria in UAC R317-2-14 or are named in the list of waters with designated use classifications in UAC R317-2-13. Lakes, reservoirs, and ponds* An inland body of standing fresh or saline water that is generally too deep to permit submerged aquatic vegetation to take root across the entire body. This type may include expanded parts of a river or natural lake, a reservoir behind a dam, or a natural or excavated depression containing a waterbody without surface water inlet and/or outlet. *Footnote: Sites associated with these waterbody types that have readily available and credible data are also subject to secondary reviews as described in the Secondary Review section and Appendix 2. Assessment Units Assessment Unit Delineation and Identification Surface waters identified for 303(d) assessments are delineated into discrete units called assessment units (AUs). AUs identify waters of the state assessed for support of their designated beneficial uses. Lakes, reservoirs, and ponds are delineated as individual AUs, and their size is reported in acres. Flowing surface waters of the state and canals are delineated by specific rivers or one or more surface water reaches in subwatersheds, and their size is reported in perennial stream miles. Additional Guidelines for Delineating Assessment Units DWQ follows the guidelines listed below when delineating AUs for flowing surface waters of the state. The first two guidelines are fixed rules. • The entire AU is within a single 8-digit USGS HUC. • With few exceptions, each AU comprises reaches with identical designated beneficial use classifications. For example, a waterbody that has beneficial uses of Class 1C, 2B, and 3A in one portion and Class 2B and 3B in another portion would have at least two distinct AUs because of the difference in beneficial use classifications. • Large flowing surface waters of the state, such as the Green River, Colorado River, and portions of other large rivers (e.g., the Bear River and Weber River) are delineated into "linear" or "ribbon" AUs containing no 22 tributaries. Where a major tributary enters these rivers, or hydrological features such as dams exist, the river is further delineated into two or more AUs. • Tributaries and headwaters were delineated primarily using the 5th- and 6th-level HUC boundaries to define the AUs. • Additional AUs were defined by combining or splitting 5th- or 6th-level watersheds using hydrological and ecological changes such as geology, vegetation, or land use. • Small tributaries to larger flowing surface waters that could not be incorporated into a watershed unit are combined into separate, unique AUs. • AU boundaries generally follow hydrologic units, but may also be delineated to reflect beneficial use designation changes, major tributaries or other observed hydrologic or chemical changes, administrative boundaries such as at some U.S. Forest Service boundaries, or notable road crossings as stated in water quality standards at UAC R317-2-13. Individual AUs for flowing surface waters of the state are assigned a unique identification code for indexing. Each AU identifier begins with the prefix “UT,” before the associated 8-digit HUC, followed by a 3-digit DWQ sequential number, and finally a two-digit sequential number indicating whether the AU is the result of resegmentation of a parent AU. Similarly, lake, reservoir, and pond AUs are identified by adding the prefix “UT-L-” to the 8-digit HUC, followed by a 3-digit sequential number, and finally a two-digit sequential number indicating whether the AU is the result of resegmentation of a parent AU. Figure 12 provides an example of how DWQ uses these guidelines to delineate and identify AUs within a major watershed. The Weber River is delineated as a linear AU from its confluence with Chalk Creek upstream to the Wanship Dam and designated as UT16020101-017_00. South Fork Chalk Creek (UT16020101-011_00) in the Chalk Creek watershed is delineated by combining two 12-digit HUCs comprising the South Fork Chalk Creek sub-basin. The first AU (UT16020101-010_00) in the Chalk Creek watershed above Echo Reservoir is delineated using the confluence of the South Fork as the upstream endpoint. This necessitated splitting the 12-digit HUC into two AUs, one for Chalk Creek below the confluence with South Fork (UT16020101-010_00) and another AU for Chalk Creek above the South Fork confluence and below the Huff Creek confluence to form UT16020101-012_00. UT16020101-019_00 AU is an example of small tributary streams that could not be combined into a hydrological based AU. These are very small tributaries, and the Weber River is not reflective of their stream order or the habitat that they flow through. Echo Reservoir (UT-L-16020101-001_00) and Rockport Reservoir (UT-L-16020101-002_00) are examples of lake or reservoir AUs. 23 Figure 12. Utah Division of Water Quality assessment unit delineations. AU Stream Mileage Estimation for Flowing Surface Waters and Canals Flowing surface water assessments are summarized by perennial stream mileage in each assessment category. Stream mileage within each AU is estimated using a streams GIS layer generated by the Utah Geographic Reference Center (UGRC). This layer was derived from the high resolution (1:24,000 scale) National Hydrologic Dataset (NHD). Stream mileage within an AU is estimated as the sum of the lengths of all perennial streams and canals identified in the site-specific numeric criteria in UAC R317-2-14 or named in the list of waters with designated use classifications in UAC R317-2-13.The NHD-based layer is only used to estimate stream mileage within an AU and is not used to define individual monitoring locations as perennial or intermittent or remove monitoring locations from the assessment process.. Waters Within and Shared with Other States Though readily available data may exist from locations near Utah’s state boundaries, DWQ only assesses monitoring sites that are within the jurisdictional boundaries of the state for 303(d) purposes. Assessment units or sites on lands under tribal jurisdiction are not assessed in the IR. Assessed surface waters of the state (as defined in Table 4) that flow into Utah but originate outside of Utah’s borders will be assessed using DWQ monitoring locations within state boundaries. Lakes, reservoirs, and ponds that overlap with other state jurisdictions (e.g., Lake Powell, Bear Lake, and Flaming Gorge) will be assessed using the monitoring locations that fall within Utah state jurisdictional boundaries. 24 DWQ will work with neighboring states, as resources allow, on any impairments that fall close to jurisdictional boundaries by notifying the neighboring state of the impairments or exceedances and available data relevant to the impairment. Data Quality Credible Data Defined All readily available data and information that are submitted to the Utah’s Integrated Report program or obtained during the IR’s data compilation process must be of high quality to be considered for 303(d) assessments. Utah’s IR program defines credible data as a complete and validated data submission consisting of • Water quality samples and field measurements (data) that are collected using appropriate quality assurance (QA) and quality control (QC) procedures, including proper documentation • Environmental data that are representative of water quality conditions at the time of sampling • Documented field sample collection, processing, and laboratory analyses that are documented and follow established protocols, procedures, and methods. Further information on proper adherence to these requirements is available upon request. Utah’s IR program relies on documentation from project planners, sample collectors, and laboratories to help ensure that data are of known quality and defensible. External entities are not obligated to collect data under the specifications of any of DWQ's or EPA's currently established quality assurance protocols to be considered credible, but all sources of data must meet the definition of credible data. DWQ will evaluate the credibility of data using the criteria and documentation described in the following sections. Please note that the definition of credible data outlined in this document is specific to Utah’s IR program and does not restrict other programs (e.g., water quality standards development, TMDLs, etc.) within DWQ from using data for other Division reporting analyses and actions. Data used for a Watershed Plan, for example, may not necessarily meet the credible data requirements for Utah’s IR program but may meet the needs of a Watershed Plan. Components for Credible Data Quality Assurance Program Plan Guidance and Example Utah’s IR program requires that all assessment-related decisions that use data are supported by a Quality Assurance Project Plan (QAPP). QAPPs “integrate all technical and quality aspects of a project, including planning, implementation, and assessment.” The purpose of a QAPP is to document planning results for environmental data operations and to provide a project-specific “blueprint” for obtaining the type and quality of environmental data needed for a specific decision or use. The QA Project Plan documents how quality assurance (QA) and quality control (QC) are applied to an environmental data operation to assure that the results obtained are of the type and quality needed and expected” (EPA, 2002). External entities may be required to provide the QAPP they relied upon for the data collection associated with a particular submission. External entities may choose to follow one of the example QAPPs below or develop a QAPP specific to their entity or sampling program(s). 25 Example QAPPs • Environmental Protection Agency’s Quality Assurance Quality Program Guidance & Requirements. EPA’s requirements and guidance documents for ensuring that all environmental data are of a known quality and defensible. Utah’s IR program encourages DWQ staff, cooperators, and all other parties interested in submitting high quality data to the IR program to review QA/R-5 and QA/G-5. • DWQ Quality Assurance Program Planning (QAPP). DWQ’s document outlining the minimum Quality Assurance and Quality Control (QA/QC) requirements for environmental data generated by DWQ and used by most of its cooperators. Sampling Analysis Plan Guidelines and Examples Sampling Analysis Plans (SAPs) are the second type of documentation that Utah’s IR program requires when compiling information for assessments and other programmatic decisions. SAPs “are intended to assist organizations in documenting the procedural and analytical requirements for one-time, or time-limited, projects involving the collection of water, soil, sediment, or other samples taken to characterize areas of potential environmental contamination. It combines the basic elements of a Quality Assurance Project Plan (QAPP) and a Field Sampling Plan” (EPA, 2014). External entities may be required to share the SAP relied upon for data collection associated with a particular submission. External entities may choose to follow one of the example SAPs below or develop a SAP specific to their sampling program(s). Example SAPs • EPA’s Sampling Analysis Plan Guidance & Requirements. • DWQ’s recommended Sampling Analysis Plan Requirements. These requirements are currently used by DWQ and its cooperators This document contains information on what DWQ looks for in a SAP (see Appendix 1) Standard Operating Procedures Guidelines and Examples Standard Operating Procedures (SOPs) are documented procedures that describe the routine operations of a monitoring program in full detail. Utah’s IR program requires SOPs as part of data submission packages to ensure consistency and comparability across sampling techniques from disparate data sources. External entities may be required to share the SOPs relied upon for data collection associated with a particular submission. External entities may choose to follow the example SOPs below or develop SOPs specific to their sampling program(s). Example SOPs • EPA’s Guidance for Preparing Standard Operating Procedures (G-6). EPA’s guidance for developing and providing the necessary documentation when generating an SOP. DWQ recommends referring to EPA’s guidance if not using DWQ’s SOP. • DWQ Standard Operating Procedure. DWQ generates SOPs for any procedure that becomes routine, even when published methods are utilized. The use of SOPs ensures data comparability, defensibility, and accuracy, and reduces bias. DWQ SOPs available on the website include macroinvertebrate collection, calibration, maintenance, and use of multiparameter water quality sondes, chlorophyll-a sampling, harmful algal bloom collection and identification, water chemistry and E. coli sample collection, among 26 Sampling Observations and Laboratory Comments Utah’s IR program requires documentation of field conditions that may affect data quality or laboratory comments on QA/QC issues encountered during analysis. Appendix 1 includes an example of sampling observations DWQ recommends documenting in the field for grab sample collections, and the credible data matrices included in Table 5 - Table 9 describe additional sampling and laboratory observations and comments required by Utah’s IR program. Monitoring Location Information DWQ must review all monitoring location information associated with datasets to assess waterbodies against the numeric criteria assigned in UAC R317-2-14. This process involves validating the location’s geospatial information in GIS, assigning beneficial uses to DWQ-validated locations, and merging monitoring locations and their associated data where locations are representative of the same waterbody or segment. Information that must be included with a monitoring location measurement: • Monitoring Location ID (organization's unique identifier for the sample site) • Waterbody type description • Monitoring location, latitude/longitude measurements and associated metadata as defined on Utah’s IR program’s Call for Data webpages. A monitoring location and its associated data will not be included in the assessment if DW Q’s geospatial review of the monitoring location information finds insufficient or inaccurate information (e.g., it cannot be mapped or is improperly recorded by the sampler in the field). Credible Data Matrices DWQ will consider the scientific rigor of the sampling information and measurements associated with sites where beneficial uses can be assigned to a DWQ-validated monitoring location. DWQ uses a data-type– specific, credible-data matrix to assess the validity of the sampling and analytical protocols associated with a sample measurement, As noted in the credible-data matrices, each credible-data matrix considers the field and laboratory QA/QC protocols, sampling and laboratory methods, analytical detection or instrumentation limits, and field observations associated with a sample measurement. DWQ assigns a grade level (A–C) to the associated sample measurement(s) based on the level of information provided and the strength of the metadata associated with the sample measurement. DWQ considers measurements that receive an A or B grade to be of high quality and will consider and use them to assign an EPA-derived assessment category to a waterbody (i.e., the IR’s 305(b) and 303(d) assessments). Measurements that receive a C grade are considered to be of insufficient quality for assessment and 303(d) listing purposes. Details on the required data quality criteria for inclusion in the IR and use by Utah’s IR program are included in Table 5. 27 Table 5. Data validation criteria for water quality field grab sample parameters. Data Quality Grade Quality Assurance Essential Metadata1 Calibration Documentation Field Documentation Flow Data Calibration: Water Temperature Methods* Calibration: pH Methods* Calibration: Dissolved Oxygen, Percent Saturation for Calibrated Meter* Calibration: Dissolved Oxygen, Concentration Methods for Calibrated Meter* A QAPP, SAP(s), and SOP(s) or equivalents are available for DWQ review if requested Essential metadata is included with the data submission. Available for DWQ review if requested for all field parameters Available for DWQ review if requested Submitted or available for DWQ review if requested Checked against NIST A ≤ ± 0.1 ºC Calibrated pH Probe A ≤ ± 0.2 0-200 %Sat: A ≤ ± 6% 0-8 mg/L: A ≤ ± 0.1mg/L > 8mg/L: A ≤ ± 0.2 mg/L B QAPP, SAP(s), and SOP(s) or equivalents are available for DWQ review if requested Essential metadata is provided to DWQ upon request. Available for DWQ review if requested, for field parameters Unavailable Not submitted or unavailable A ≤ ± 0.1 ºC Calibrated pH Probe A ≤ ± 0.2 0-200 %Sat: A ≤ ± 10% 0-20 mg/L: A ≤ ± 0.2 mg/L C QAPP, SAP, or SOP is unavailable Not Submitted Essential metadata is missing from the data submission and is unavailable. Unavailable Unavailable Not submitted or unavailable A ≥ ± 0.5 ºC OR not a calibrated meter, missing, or rejected data Not a calibrated meter, missing, or rejected data Not a calibrated meter, missing, or rejected data Not a calibrated meter, missing, or rejected data 1 Essential metadata elements are sample location (latitude/longitude), waterbody type, sample date and time, parameter name, result value and unit. *Footnote: A = accuracy, values based on technical specifications of commonly used YSI, Hydrolab, and In-Situ smarTROLL sondes. 28 Table 6. Data validation criteria for water quality high frequency dissolved oxygen data. Data Quality Grade Quality Assurance Quality Assurance Project Plan (QAPP) Essential Metadata1 Calibration Documentation Data QA/QC Information or Report Field Documentation Flow Data Calibration: Dissolved Oxygen*, Percent Saturation for Calibrated Meter Calibration: Dissolved Oxygen*, Concentration Methods for Calibrated Meter A QAPP, SAP(s), and SOP(s) or equivalents are available for DWQ review if requested Essential metadata is included with the data submission. Mandatory-calibration record(s) (e.g., field records of calibration and/or fouling) Documentation describing the QA/QC process on the raw data All pertinent deployment data (i.e., information necessary for interpreting data) Submitted or available for DWQ review if requested 0-200%: A ≤ ± 6% 0-8 mg/L: A ≤ ± 0.1 mg/L > 8mg/L: A ≤ ± 0.2 mg/L B QAPP, SAP(s), and SOP(s) or equivalents are available for DWQ review if requested Essential metadata is provided to DWQ upon request. Mandatory-calibration record(s) (e.g., field records of calibration and/or fouling) Documentation describing the QA/QC process on the raw data All pertinent deployment data (i.e., information necessary for interpreting data) Not submitted or unavailable 0-200%: A ≤ ± 10% 0-20 mg/L: A ≤ ± 0.2 mg/L C QAPP, SAP, or SOP is unavailable Essential metadata is missing from the data submission and is unavailable. Unavailable Unavailable Unavailable Not submitted or unavailable Missing, or rejected data 1 Essential metadata elements are sample location (latitude/longitude), waterbody type, sample date and time, parameter name, result value and unit. *Footnote: A = accuracy, values based on technical specifications of commonly used YSI, Hydrolab, and In-Situ smarTROLL sondes. Please note: Raw and QA/QC data records must be submitted to qualify for consideration in 303(d) assessments. 29 Table 7. Data validation criteria for water quality chemistry grab sample parameters. Data Quality Grade Quality Assurance Project Plan (QAPP) Essential Metadata1 Laboratory Method Detection Limits Lab Certification QC Data Laboratory Comments Field Documentation Metals* Organics* Inorganics* A QAPP, SAP(s), and SOP(s) or equivalents are available for DWQ review if requested Essential metadata is included with the data submission. Standard Methods Below applicable water quality standard Utah Bureau of Laboratory Improvement certification, NELAC, or equivalent Available for DWQ review if requested Laboratory Comments Associated with Sample Available for DWQ review if requested Chronic: Aluminum submitted with Ca and Mg OR Lab Hardness and field pH; Cadmium, Chromium (III), Copper, Lead, Nickel, Silver, and Zinc submitted with Ca and Mg OR Lab Hardness Pentachlorophenol submitted with field pH Total Ammonia as N submitted with field pH or field Temperature B QAPP, SAP(s), and SOP(s) or equivalents are available for DWQ review if requested Essential metadata is provided to DWQ upon request. Standard Methods Below applicable water quality standard Documentation of laboratory procedures Available for DWQ review if requested Laboratory Comments Associated with Sample Unavailable Chronic: As above, but Aluminum submitted without Hardness or field pH will be assessed at 750 ug/l; As above, but samples submitted without Ca, Mg, or Lab Hardness ** Pentachlorophenol submitted without field pH Total Ammonia as N submitted with field pH or field Temperature C QAPP, SAP, or SOP is unavailable Essential metadata is missing from the data submission and is unavailable. Missing or Non- Standard Methods Above applicable water quality standards No certification or laboratory documentation Unavailable No Laboratory Comments Unavailable Chronic: As above, but Aluminum without Hardness or field pH will not be assessed; Pentachlorophenol submitted without field pH Total Ammonia as N submitted with field pH or field Temperature 1 Essential metadata elements are sample location (latitude/longitude), waterbody type, sample date and time, parameter name and fraction, parameter units, analytical method, result value or non-detect limitation, and laboratory name. *Footnote: Please also refer to UAC R317-2 to confirm that all the necessary data is submitted to DWQ so correction factors and equations may be fully calculated for 303(d) assessment purposes. **Footnote: Please refer to the 303(d) Assessment Methods for corrections to assessment due to missing values of hardness or pH. 30 Table 8. Data validation criteria for macroinvertebrate data. Data Quality Grade Quality Assurance Project Plan (QAPP) Essential Metadata1 Field Documentation Qualified taxonomy lab A EPA-approved Lab QAPP available for DWQ review if requested; SAP and SOP or equivalents available for DWQ review if requested Essential metadata is provided to DWQ upon request. Available for DWQ review if requested Required B Lab QAPP or equivalent is available for DWQ review if requested; SAP and SOP or equivalents available for DWQ review if requested Essential metadata is provided to DWQ upon request. Unavailable Required C QAPP, SAP, or SOP is unavailable Essential metadata is missing from the data submission and is unavailable. Unavailable Unavailable 1 Essential metadata elements are sample location (latitude/longitude), waterbody type, sample date and time, parameter name and fraction, analytical method, result value and unit, and laboratory name. 31 Table 9. Data validation criteria for Escherichia coli (E. coli) data. Data Quality Grade Quality Assurance Essential Metadata1 EPA Approved Method Lab Documentation QA/QC A QAPP, SAP(s), and SOP(s) or equivalents are available for DWQ review if requested Essential metadata is provided to DWQ upon request. IDEXX Colilert Bench Sheet Present and Complete Information on holding time, incubation*, and expiration dates provided. B QAPP, SAP(s), and SOP(s) or equivalents are available for DWQ review if requested Essential metadata is provided to DWQ upon request. IDEXX Colilert or EasyGel Bench Sheet Present, incomplete, or not available Not provided C QAPP, SAP, or SOP is unavailable Essential metadata is missing from the data submission and is unavailable. IDEXX Colilert or EasyGel Unavailable Not provided 1 Essential metadata elements are sample location (latitude/longitude), waterbody type, sample date and time, parameter name and fraction, analytical method, result value and unit, and laboratory name. *Footnote: "incubation" refers to data and information that is recorded on DWQ's E. coli bench sheets and relates to time and temperature (i.e., time samples were placed in and taken out of the incubator and the temperature of the incubator when samples were placed in and taken out of it). For an example of how DWQ records this information, please refer to Appendix 1 of DWQ's Standard Operating Procedure for Collection, Handling, and Quantification of Escherichia coli (E. coli) Samples. 32 Data Submission Process Type of Data to Submit As referenced in 40 CFR 130.7(b)(5), Utah’s IR program considers all existing and readily available data as defined in Table 3. Both quantitative and qualitative data may be used to evaluate whether physical, chemical, and biological characteristics of a waterbody are sufficient to support that waterbody’s designated uses. However, based on the type of data submitted to or obtained by DWQ during Utah’s IR program’s Call for Data, some of these data may not be appropriate for assessments. DWQ considers several quantitative and qualitative types of data described in Table 10 for water quality assessments and analyses as recommended in EPA’s July 29, 2005, guidance (EPA, 2005). Table 10. Summary of data types considered by Utah’s IR program. Utah’s IR program Data Uses Quantitative Data Qualitative Data Other 305(b) and 303(d) Assessments (Grade A and B Data in credible data matrices) (1) Assessment parameters contained in Utah Water Quality Standards (UAC R317-2) and Safe Drinking Water Act Standards, (2) segment-specific ambient monitoring of analytical, physical, and/or biological conditions, (3)simple dilution calculations, and (4) human health/consumption closures, restrictions, and/or advisories (1) Observed effects (e.g., fish kills), (2) complaints and comments from the public, and (3) human health/consumption closures, restrictions, and/or advisories Landscape analysis (when applicable) Monitoring Planning and Training (Grade C and D Data in credible data matrices) See above See above (1) Landscape analysis (when applicable), (2) technical reports, (3) white papers, (4) articles from referred journals, and (5) other scientific publications Period of Record DWQ uses water years to define the period of record and uses the same definition of water years as the U.S. Geologic Survey. USGS defines the water year as the 12-month period between October 1 and September 30 of the following year. For the 2024 IR, the period of record is October 1, 2016, to September 30, 2022, (water years 2017-2022). Data and information from the IR’s period of record are considered to be most reflective of the current conditions of a waterbody. DWQ will analyze and assign EPA-derived assessment categories to the assessed waterbodies from this record period, provided the data meet the interpretive, sampling, and analytical considerations and protocols outlined in this document (see Table 1). Older Data and Information DWQ will not consider data and other information older than the period of record in the current IR and 303(d) list unless the data are used to support a secondary review of an impairment determination. Instead, DWQ 33 will encourage the data submitter to collect newer information and submit those data and information in future calls for data. The IR’s period of record does not preclude DWQ from using older or longer-term datasets for programs other than assessments (e.g., water quality standards development, TMDLs, etc.). Newer Data and Information Quantitative and qualitative data types that are considered in 303(d) assessments but are collected or represent conditions after the closing date specified in the above period of record will not be considered in the current reporting cycle. DWQ does not include these newer datasets because of the time required to compile data, perform data quality checks, format data from different sources, assess, review assessments, and generate the IR and 303(d) for public comment by April 1 of even-numbered years. Data Submission Tools Data should be submitted in a form that is compatible with the Utah’s IR program’s existing data-management and QA capabilities. Please refer to Table 3 for more information on how to submit data for consideration in the IR. Data Preparation for Conventional and Toxic Assessments for All Waters DWQ com piles all high quality data within the period of record following the readily available and credible data reviews, and then standardizes, validates, and prepares the data for assessments. To assist reviews and increase transparency to reviewers, DWQ uses a series of comments and flags rather than altering raw data and accompanying metadata. Though High Frequency Dissolved Oxygen (DO) and E. coli assessments are considered conventional assessments (see Table 11), these parameters have data preparation protocols that are unique to those datasets. Please refer to the High Frequency and E. coli assessment sections of this document for more details. Results below Detection Limits Environmental chemistry laboratories often report sample results as below their detection limit for a given analytical method. These limits are variously reported as minimum detection limit, minimum reporting limit, and/or minimum quantitation limit. The reported result value or a value of 0.5 times the lowest reported detection limit for sample results below detection is applied for purposes of the assessment. DWQ screens and flags laboratory result values that are empty and have detection limits higher than the water quality criteria in UAC R317-2-14; these flagged data records are not considered in the assessment. Duplicate and Replicate Results Datasets often contain duplicate and replicate sample results due to QA/QC procedures, reporting errors, or sampling design. In these cases, a single daily value is determined by accepting the highest result for parameters with not-to-exceed criteria in UAC R317-2-14, or the lowest reported value for parameters with minimum criteria in UAC R317-2-14. All data are retained in the assessment dataset and flagged as rejected because of replicate or duplicate values. 34 Initial Assessment: Monitoring Location Site Level DWQ determines attainment or nonattainment of numeric standards by assessing credible data at the monitoring location site level against the numeric criteria in UAC R317-2-14. DWQ developed this protocol because individual assessments offer a more direct measure of the support or non-support of water quality standards in UAC R317-2. Multiple parameter assessments at an individual monitoring location and results from multiple monitoring locations within the same AU are summarized and combined using the procedures outlined in the Determination of Impairment: All Assessment Units section of this report. Assessments Specific to Rivers, Streams, and Canals Conventional Parameter Assessments DWQ currently assesses five parameters within UAC R317-2-14 as conventional parameters and assesses them against the beneficial-use specific criteria established in UAC R317-2. Several waterbodies with conventional numeric criteria have site-specific standards articulated in self-explanatory footnotes within DWQ’s surface water standards (UAC R317-2-14). Site-specific standards that require further clarification for 303(d) assessment purposes are noted and explained in Table 11. Sites that do not meet water quality standards as described below are not supporting of beneficial uses for 303(d) assessment purposes. Table 11. Conventional parameters and associated designated uses as identified for assessment purposes. Parameters Designated Use Notes DO* Aquatic life DO measurements are assessed against the minimum, 7-day average, and 30-day average criteria in UAC R317-2-14. Grab samples are assessed following the processes in Figure 13 for rivers and streams and the "Assessments Specific to Lakes, Reservoirs, and Ponds" sections of the methods. High frequency DO datasets are assessed following the processes in Figures 3-5. Note: DWQ will assess against early life stage (ELS) criteria where ELS presence has been confirmed in a specific waterbody. Site specific standards are used for assessment where they have been developed. Maximum temperature* Aquatic life Some site-specific standards are used for assessment purposes. pH* Domestic, Recreation, Aquatic life Criteria are identical across uses. 35 Parameters Designated Use Notes Total dissolved solids (TDS)** Agriculture Many site-specific standards are used for assessment purposes. Clarification on how three site-specific standards are used for 303(d) purposes are provided below: (1) For South Fork Spring Creek from the confluence with Pelican Pond Slough Stream to U.S. Route 89, two seasonal assessments are not performed. Instead, each sample is compared to the monthly corrected criteria in the footnote in UAC R317-2. (2) Ivie Creek and its tributaries from the confluence with Muddy Creek to the confluence with Quitchupah Creek. If TDS exceeds the site-specific standard, the site is not meeting site-specific criteria. If TDS is not exceeding, total sulfate is assessed. (3) Quitchupah Creek from the confluence with Ivie Creek to Utah State Route 10: If TDS exceeds the site-specific standard, it is not meeting site- specific criteria. If TDS is not exceeding, total sulfate is assessed. (4) Blue Creek and tributaries, Box Elder County, from Bear River Bay, Great Salt Lake to Blue Creek Reservoir. The only site to be assessed within this area is 4960740. (All other sites within this area description will not be assessed for TDS). Sulfate** Agriculture Site-specific standard associated with sulfate for the following areas: (1) Ivie Creek and its tributaries from the confluence with Muddy Creek to the confluence with Quitchupah Creek: When TDS is not exceeding site- specific criteria and total sulfate exceeds site-specific criteria, the area does not meet water quality standards. (2) Quitchupah Creek from the confluence with Ivie Creek to Utah State Route 10: When TDS is not exceeding site-specific criteria and total sulfate exceeds site-specific criteria, the area does not meet water quality standards. *Footnote: Indicate that assessments are performed from field measurement only. **Footnote: Indicate that assessments are performed from lab measurements only. Grab Sample Assessments A minimum of 10 samples for conventional parameters are required to determine if a site is meeting or not meeting water quality standards (Figure 13). Where locations have sufficient sample sizes of 10 or more, an exceedance percentage is calculated for each applicable beneficial use by dividing the number of samples exceeding the numeric criterion by the total number of samples. If the calculated percentage is less than or equal to 10%, the site is supporting its beneficial use. If the calculated percentage is greater than 10%, the site is not supporting its beneficial use. This assessment is repeated for each beneficial use and numeric criterion. In the case of waterbodies with site-specific standards for TDS and sulfate, both criteria must be met or the waterbody will be listed as not supporting its agricultural use. 36 Figure 13. Overview of the assessment process for conventional parameters using grab sample data. High Frequency Assessments for Dissolved Oxygen Data Preparation High frequency data are often screened and corrected to account for sensor drift, calibration shift, strange anomalous points, and battery issues before data analysis and interpretation begins. These data screens are particularly important for dissolved oxygen (DO) sensors because they are subject to bio-fouling, especially in nutrient-rich water where they have the higher potential to become covered in algal growth. When bio-fouling occurs, it results in erroneous logger measurements or sensor drift. DWQ will use corrected high frequency data as documented by the data submitter for assessments. DWQ will contact the data submitter for clarification and additional information if it determines additional corrections may be required. Data sufficiency High frequency data must capture complete days to ensure daily minima are captured and daily averages can be accurately calculated. DWQ defines a complete day as a calendar day (i.e., 12:00 a.m. – 11:59 p.m.) in which at least one measurement is made in each hour. Incomplete days will not be included in the high frequency DO assessment. 37 Assessment Process A daily minimum and daily average are calculated for each complete day in a dataset. Moving 7- and 30-day averages are then calculated from the daily averages for each 7- or 30-day period within the dataset. These values are then compared to the applicable daily minimum, 7-day average, and 30-day average criteria to determine use impairment or support. A site does not meet the daily DO minimum criterion if the percentage of total daily minima that fall below the applicable standard is greater than 10% within the period of record (Figure 14). Figure 14. Overview of the assessment process for the minimum dissolved oxygen, minimum, using high frequency data. 38 A site does not meet the 7-day average criterion if the percentage of 7-day averages that fall below the applicable standard is greater than 10% within the period of record (Figure 15). Figure 15. Overview of the assessment process for the minimum dissolved oxygen, 7-day averages using high frequency data. 39 A site does not meet the 30-day average criterion if the percentage of 30-day averages that fall below the applicable standard is greater than 10% within the period of record (Figure 16). Figure 16. Overview of the assessment process for the minimum dissolved oxygen, 30-day averages, using high frequency data. A site is considered not supporting if it is not meeting either of the daily minimum, 7-day average, or 30-day average criteria. A site is considered fully supporting if 10% or fewer violations are observed for all three criteria. This process (Figure 14 – Figure 16) is repeated until each beneficial use has been assessed. Analyzing Multiple DO Datasets at a Site DWQ assesses grab and high frequency data independently during the initial assessment of DO at a site and reviews these assessments in the context of one another during the secondary review for determining impairment. These processes are discussed in greater detail in Determinations of Impairment: All Assessment Units 40 Nutrient Assessments Specific to Headwater Streams Utah’s Numeric Nutrient Criteria (NNC) require consideration of both ambient nutrient concentrations and ecological response data for headwater streams, which are defined as streams where antidegradation category 1 or 2 protections have been established (UAC R317-2-3). Generally, this includes streams above United States Forest Service (USFS) boundaries—about 50% of all perennial streams statewide. Support of Aquatic Life Uses The NNC applicable to aquatic life include two thresholds for total nitrogen (TN) and total phosphorus (TP) based on the arithmetic average of a minimum of four samples obtained during the growing season (UAC R317-2-14.8). The growing season is defined by the NNC as the period of algal growth through senescence. For assessment purposes, DWQ assumes that the growing season includes the months of June through November, although this may be lengthened where additional information demonstrates that a longer period of growth is warranted. The arithmetic average of TN or TP, derived from four or more growing season samples, is used to place headwater streams into one of three enrichment tiers (Table 12). Lower criteria thresholds of 0.4 mg/L TN and 0.035 mg/L TP differentiate between low and moderate enrichment streams. Higher thresholds of 0.80 mg/L TN and 0.080 mg/L TP differentiate between moderate and high enrichment streams. The higher of TN or TP enrichment tiers is used to determine whether or not nutrient enrichment has degraded aquatic life uses at a site. Moderate enrichment streams, with average nutrient concentrations between the upper and lower thresholds, require additional measures of ecological condition to determine whether or not a headwater stream is attaining the NNC water quality standards (Table 12). Nutrients can degrade aquatic life uses via mechanisms related to increased growth of plants/algae (autotrophs) and/or microbes/fungi (heterotrophs). In the case of plant/algae growth, two ecological responses are not-to-be-exceeded at any headwater stream: (1) a daily gross primary production (GPP) rate higher than 6 g O2/m2/day or (2) an aerial percent filamentous algae cover exceeding 1/3 of the stream bed. Adverse heterotrophic responses are addressed using ecosystem respiration (ER), which measures the net metabolic activities of all stream biota and is used to understand linkages among microbes/fungi, nutrients, and aquatic life uses. NNC establishes a not-to-be-exceeded rate for ER of 5 g O2/m2/day. Any site where TN or TP falls between the NNC thresholds is categorized as not supporting its aquatic life uses if any of the three responses exceeds the adverse effect thresholds, even if a complete set of responses is not available (Table 13). However, a moderately enriched stream site must have all three response parameters collected and occurring below their adverse effect thresholds to obtain a full support assessment for the site. If any response parameters are unavailable despite other response parameter(s) meeting criteria, the site will be assessed as insufficient data (3A) and the division will prioritize the data collection necessary to make a site assessment. Any site where the growing season average of both TP and TN falls below the lower NNC thresholds (lowest enrichment tier) is considered to be supporting aquatic life uses with respect to nutrient enrichment (Table 13) provided that all three ecological responses have been measured and fall below the threshold that demarcates degraded conditions. If any response parameters are above their degraded condition threshold, the site will be assessed as impaired (Category 5) At the other end of the enrichment gradient, any site where the average TN or TP concentration exceeds the upper NNC threshold (high enrichment tier) is categorized as threatened unless degradation is confirmed by an ecological response, in which case it is considered impaired (not supporting aquatic life uses). Threatened 41 AUs are designated as category 5 due to highly enriched conditions, but the Division commits to more thoroughly evaluate the AU for adverse nutrient-related responses. 42 Table 12. Numeric Nutrient Criteria and Associated Ecological Responses (Bioconfirmation Criteria) to Protect Aqu atic Life Uses in Antidegradation Category 1 and 2 (UAC R317-2-12) Headwater Perennial Streams. Nutrient Enrichment Level Summertime Average Nutrients Ecological Response Assessment Notes Low TN < 0.40a,b TP < 0.035a,b Fully supporting biological uses if the average of ≥ 4 summertime samples is below the specified nutrient concentration of either TN and TP unless ecological responses specified for moderate enrichment streams are exceeded. Sites with fewer samples will not be assessed for nutrients. Moderate TN 0.40–0.80a TP 0.035–0.080a Plant/Algal Growthc< 1/3 or more filamentous algae coverd,e OR GPPc of < 6 g O2/m2/day OR Plant and Microbial Growth ERc < 5 g O2/m2/day Headwater streams within this range of nutrient concentrations will be considered impaired (not supporting for nutrients) if any response exceeds defined thresholds. Streams without response data will be listed as having insufficient data and prioritized for additional monitoring if either TN or TP falls within the specified range. High TN > 0.80a,b TP > 0.080a,b Streams over these thresholds will initially be placed on Utah’s Section 303(d) list as threatened. Threatened streams will be further evaluated using additional data such as nutrient responses, biological assessments, or nutrient-related water quality criteria (e.g., pH and DO) both locally and in downstream waters. Notes: Criteria would be applicable unless more restrictive total maximum daily load (TMDL) targets have been established to ensure the attainment and maintenance of downstream waters. DO = dissolved oxygen, ER = ecosystem respiration, GPP = gross primary production, TN = total nitrogen in mg/L, and TP = total phosphorus in mg/L. a Seasonal average of ≥ 4 samples collected during the summertime growing season (June 1–September 30) will not be exceeded. Sites will be assessed using the higher of TN and TP threshold classifications. b Response data, when available, will be used to assess aquatic life use support or as evidence for additional site-specific investigations to confirm impairment or derive and promulgate a site-specific exception to these criteria. c Daily whole stream metabolism obtained using open-channel methods. Daily values are not to be exceeded on any collection event. d Filamentous algae cover means patches of filamentous algae > 1 cm in length or mats > 1 mm thick. Daily values are not to be exceeded at any time during the growing season (June 1–September 30). e Quantitative estimates are based on reach-scale averages with at least three measures from different habitat units (i.e., riffle, run) made with quantitative visual estimation methods. f Excluded waters identified in UAC R317-2-13.2 (c). 43 Table 13. Decision Matrix That Will Be Used to Assess Support of Headwater Aquatic Life Uses for Nutrient-related Water Quality Problems Ecological Responses Nu t r i e n t Da t a ( T N or T P ) No Data < All Criteria > Any Criterion No Data or < 4 Samples Not Assesseda Not Assesseda Impaired (5)b < Low Threshold Not Assesseda Fully Supporting (1 or 2)d,f Impaired (5) b,e Between Lower and Upper Threshold Insufficient Data (3A)c Fully Supporting (1 or 2)d,g Impaired (5) Above Upper Threshold Threatened (5)f, Threatened (5)e,f Impaired (5) Note: Associated Integrated Report categories are in parentheses. aThere are insufficient nutrient-related data to assess whether or not aquatic life uses are supported; however, aquatic life uses may be assessed with other water quality parameters. bSites where an ecological response threshold has been exceeded, but the lower TN and TP thresholds have not will be listed as impaired on the basis of a biological assessment; cause will be listed as unknown pending follow-up investigations. cSites where TN or TP fall below the upper threshold, but above the lower threshold, and lack measures for at least one response variable will not be assessed with respect to nutrients. These sites will be prioritized for follow-up monitoring. dThe integrated report distinguishes between sites where at least one parameter has been evaluated for all uses (Category 1) and sites where some uses are supported, and other uses are either not supported or not assessed (Category 2). eSites where nutrient and ecological response data are in conflict may be candidates for site-specific criteria. fSites below the both lower TN and TP thresholds with at least one response below the lower threshold will be considered to be fully supporting aquatic life uses unless another nutrient-related criterion (e.g., pH, DO) suggests otherwise. Sites without at least one measured response are not assessed. gSites between the lower and upper threshold require all three response parameters to be considered fully supporting with respect to nutrient enrichment. 44 Support of Recreational Uses Excessive nutrients can also degrade recreational uses. To protect these uses in headwater streams the NNC establish a not-to-be-exceeded benthic algae concentration of 125 mg/chlorophyll-a (chl-a)/m2, or the equivalent 49 g ash free dry mass (AFDM)/m2 (UAC R317-2-14.7). A site where any reach-scale biomass value exceeds either threshold will be categorized as not supporting recreational uses (Figure 17). Figure 17. Overview of the assessment process to determine support of recreational life uses based on nutrient enrichment in headwater streams. 45 Narrative Standards: Biological Assessments Utah’s beneficial uses for aquatic life require the protection of fish (cold water or warm water species) and the organisms on which they depend (UAC R317-2-6.3). DWQ uses an empirically based model that directly assesses support of aquatic life uses by quantifying the integrity of macroinvertebrate assemblages. The biological integrity of sites is evaluated as a numerical index (Hawkins, 2006; Hawkins et al. 2010) calculated using a comparison of the biological composition observed at a focal site against a subset of ecologically similar reference sites (Hughes et al.,1986; Suplee et al.,2005). River Invertebrate Prediction and Classification System Models DWQ uses the River Invertebrate Prediction and Classification System (RIVPACS) model approach to quantify biological integrity (Wright, 1995). RIVPACS is a classification of freshwater sites based on macroinvertebrate fauna used to predict invertebrate taxa expected to occur under reference conditions. DWQ’s RIVPACS model was verified and reconstructed by the USU BugLab. RIVPACS models compare the list of taxa that are observed (O) at a site to the list of taxa expected (E) with the least-human-caused disturbance for a similar site to quantify biological condition. Predictions of E are obtained empirically from reference sites that together are assumed to encompass the range of ecological variability observed among streams in the region where the model was developed. In practice, these data are expressed as the ratio O/E, the index of biological integrity (Figure 18). More information on Utah’s RIVPACS model can be found on the DWQ website. Figure 18. A hypothetical example of O/E as a standardization of biological assessments. 46 Assessing Biological Use Support DWQ does not have numeric biological criteria. However, DWQ has narrative biological criteria (UAC R317-2- 7.3) that specify how quantitative model outputs are used to guide assessments. A systematic procedure to make the narrative assessments as rigorous as possible was devised to use the RIVPACS model O/E values to determine aquatic life beneficial use support (Figure 19). The goal of this assessment process is to characterize each AU as fully supporting or not supporting aquatic life beneficial uses. Figure 19. Decision tree for making biological assessment decisions. 47 Although many AUs contain a single biological monitoring location, some AUs contain multiple sites. In such instances, DWQ staff examines available data to determine if multiple sites in an AU score similarly. When comparisons suggest that sites in one AU are ecologically similar, O/E scores from all sites in an AU are averaged for assessment purposes, provided that conclusions of biological condition are similar. If O/E scores differ appreciably among multiple sites in an AU, DWQ will investigate possible explanations for such discrepancies (see the Assessment Unit Re-segmentation discussion for more information on that process). Additionally, if only one site is sampled in an AU, it is examined to determine whether it is an appropriate representation of the AU. To translate the O/E values into assessment categories, it is necessary to devise thresholds, or O/E scores that indicate whether or not a site is meeting biological beneficial uses (Table 14). The 10th and 5th percentiles of reference sites were used for these assessments. The data used for the current assessment calculate the threshold based on 5th percentile at 0.69, whereas the 10th percentile is 0.76. These thresholds will provide the bounds according to sample strength. The data are averaged across six years since the most recent year of available data. Multiple years are preferred for assessments because O/E scores can vary from year to year and assessments are based on average conditions. Assessments based on the average condition of three or more samples reduce the probability of making an error of biological beneficial-use support as a result of an unusual sampling event (e.g., following a flash flood, or a sample that was preserved improperly). Table 14. Beneficial use support determination for O/E values obtained from different sample sizes. Sample Size O/E Threshold Use Determination Comments ≥ 1 sample collected over 6 years Mean O/E score ≥ 0.76 Fully Supporting Threshold based on 10th percentile of reference sites ≥ 3 samples collected over 6 years Mean O/E score < 0.76 Not Supporting Threshold based on 10th percentile of reference sites < 3 samples Mean O/E score ≥ 0.69–≤ 0.76 Insufficient Data Lower threshold based on 5th percentile of reference sites < 3 samples 2 O/E scores < 0.69 Not Supporting Threshold based on 5th percentile of reference sites < 3 samples 1 O/E score < 0.69 Insufficient Data Threshold based on 5th percentile of reference sites AUs not meeting biological thresholds will be assessed as not supporting. Assessments of more than three samples with average O/E scores of greater than or equal to 0.76 have a low probability of being misclassified as nonsupport. Alternatively, assessments with fewer than three samples with an average O/E score of less than 0.69 have a 5% probability of being misclassified as nonsupport. To ensure that one sample was not incorrectly misapplied, at least two samples with a score of 0.69 or less will be required to consider an AU not meeting the aquatic life use. Assessments with fewer than three samples that have a mean O/E score of greater than or equal to 0.69 and less than 0.76 will be placed in Category 3 (insufficient data and information with exceedances), which indicates that there are insufficient data to make an assessment. All sites listed as Category 3 with exceedances will be given a high priority for future biological monitoring. 48 Assessments Specific to Lakes, Reservoirs, and Ponds Assessment Overview Lakes, reservoirs, and ponds are classified by basin in UAC R317-2-13.12, with the accompanying tables listing their designated beneficial uses. Waterbodies not specifically listed are assigned beneficial uses by default to the classification(s) of the tributary stream(s). Numeric water quality criteria for both toxic and conventional parameters are assigned for each designated use in UAC R317-2-14, Deeper lakes naturally stratify thermally, which affects how conventional water quality parameters are assessed (UAC R317-2-14),so each waterbody is evaluated for thermal stratification and assessed appropriately. Utah lake and reservoir assessments are divided into two tiers: Tier I The Tier I assessment is the preliminary determination of beneficial use support for recreational use (Class 2), aquatic life (Class 3), and agricultural (Class 4), classes based on conventional parameters such as DO, temperature, and pH, toxic parameters, and E. coli. When Tier I data are not available, DWQ may rely on Tier II data to make an initial assessment. The waterbody will be classified as mixed or stratified based on the depth profile information when considering aquatic life use support within this tier. If it is a stratified waterbody, the evaluation of conventional parameters will follow the protocol designed to evaluate the sufficiency of aquatic life habitat. If the waterbody is mixed, it will follow the assessment protocol that evaluates the entire depth profile. Tier II The Tier II assessment looks further into specific weight of evidence criteria (trophic state index [TSI], fish kills, and algal composition) through secondary reviews. The Tier I preliminary support status may be modified through evaluation of the TSI, water quality related fish kills, and the composition and abundance of cyanobacteria, also known as harmful algal blooms. The Tier II evaluation could adjust the preliminary support-status ranking if at least two of the three criteria indicate a different support status. Tier I Assessment Drinking Water Use Support Drinking water use support is assessed through evaluations of pH, toxics, E. coli, and harmful algal blooms (HABs). Please review the Toxics Parameter Assessments for All Waters, Escherichia Coli Assessment for All Waters, and Harmful Algal Blooms (HAB) assessment sections for further information regarding drinking water use assessments for toxics, E. coli, and HABs. The evaluation process of pH is the same as the requirements for aquatic life uses described below. Recreational Use Support Recreational use support is assessed through evaluation of pH, E. coli, and HABs. The pH evaluation is the same as the requirements for aquatic life uses described below. Please review the Escherichia Coli Assessment for All Waters and HAB assessment sections for further information regarding recreational use assessments for E. coli and HABs. Beneficial Use Not Supported 49 No Aquatic Life Use Support Lake monitoring routinely involves collecting pH, temperature, and DO measurements at approximately one- meter intervals throughout the water column from the surface to the lake bottom. (Note: the measurement interval may be modified in the field depending on waterbody depth). These water column measurements are compared against Utah water quality standards to assess beneficial use support (Figure 20). A separate process is used to determine whether sufficient habitat is available for aquatic life for waterbodies that are thermally stratified (Figure 21). pH, All Lakes and Reservoirs Beneficial Use Supported The beneficial use is supported if the number of violations are less than or equal to 10% of the measurements (see Figure 21, Panel A). Figure 20. Process using conventional (nontoxic) parameters to assess lakes that are mixed. 50 The beneficial use is not supported if greater than 10% of the measurements (minimum of two discrete measures outside thresholds) violate the pH criterion (Figure 21, Panel B). Figure 21. Plots of pH measurements (blue dots) against lake depth for a waterbody meeting (Panel A) and violating (Panel B) the pH water quality standards. 51 Temperature and Dissolved Oxygen: Mixed Lakes and Reservoirs Temperature The criteria used to assess the beneficial use support are based on profile data. If the temperature criterion is exceeded in more than 10% of the measurements, with a minimum of two discrete measures exceeding criteria from any individual sampling event, the site is considered to be not supporting of aquatic life uses. Beneficial Use Fully Supported The beneficial use is supported if the number of violations is less than or equal to 10% of the measurements (see Figure 22, Panel A). The beneficial use is not supported if more than 10% of the measurements violate the temperature standard (see Figure 22, Panel B). Figure 22. Plots of temperature measurements (blue dots) against lake depth for two sites to provide an example of assessment procedures. Note: The red line illustrates a temperature criterion of 20 degrees Celsius: Class 3A beneficial use. 52 Dissolved Oxygen The DO assessment uses data gathered from profiles. The DO assessment uses the minimum criteria of 4.0 mg/L for Class 3A waters and 3.0 mg/L for Class 3B and 3C waters (UAC R317-2-14, Table 2.14.2). State standards account for anoxic or low DO conditions that may exist in the bottoms of deep waterbodies (UAC R317-2-14). For that reason, DO assessments for stratified lakes and reservoirs follow the stratified lakes and reservoirs assessment methods below. Beneficial Use Supported The beneficial use is supported if at least 90% of the oxygen measurements are greater than the standard. Beneficial Use Not Supported The beneficial use is not supported if greater than 10% of the oxygen measurements are below the DO standard during any single sampling event. Temperature and Dissolved Oxygen: Stratified Lakes and Reservoirs When sample locations demonstrate stratification, a separate assessment technique for temperature and DO is used to ensure that sufficient habitat for aquatic life exists. Habitat is considered sufficient if at least three continuous meters of the water column are meeting the criteria for both temperature and DO. The rationale for a conclusion of beneficial use support based on the existence of adequate habitat follows the decision diagram (Figure 23). Figure 24 provides an example of supporting and not supporting beneficial uses based on the DO and temperature data above the thermocline. Figure 23. Beneficial use support based on the existence of adequate habitat. 53 Beneficial Use Supported The beneficial use is supported if there is sufficient habitat, defined as three continuous meters of the water column meeting the criteria for both temperature and DO. Beneficial Use Not Supported The beneficial use is not supported if there is insufficient habitat for aquatic life based on the DO and temperature profile. Figure 24. Concept of the habitable zone where both DO and temperature are suitable for aquatic life. The site depicted on the top (Panel A) would be considered supporting because the lens where both temperature and DO provide sufficient habitat is greater than t Total Dissolved Solids: Agricultural Use Support The following rules are used to determine whether a lake is supporting its agricultural beneficial use (Figure 25): Beneficial Use Supported The beneficial use is supported if the standard is exceeded in 10% or fewer of TDS samples. Beneficial Use Not Supported The beneficial use is not supported if the TDS standard is exceeded in more than 10% of TDS samples. 54 Figure 25. Assessment process to determine support of the agricultural beneficial use with TDS data. Tier II Assessment Weight of Evidence Criteria The weight of evidence criteria allows DWQ to use key lines of evidence for assessing a waterbody’s beneficial use support, including evaluations of Utah’s narrative standard. The weight of evidence evaluation consists of three components: • Increasing trophic state index (TSI) trend over the long term (approximately 10 years) or a TSI-Chl-a greater than 50 (see Carlson’s Trophic State Index section below for more information) • The observation of water quality based fish kills (see the Narrative Standards for All Waters for more information) or winter DO measures not meeting the criterion when measured • Evaluation of phytoplankton community . 55 Figure 26. Tier II assessment process for lakes, reservoirs, and ponds. Carlson’s Trophic State Index The Carlson's TSI is calculated using Secchi disk transparency, total phosphorus, and chlorophyll a. TSI value ranges from 0 to about 100, with increasing values indicating a more eutrophic condition. TSIs are calculated independently for each indicator (i.e., Secchi disk, chlorophyll a, and total phosphorus) and are not averaged. Chlorophyll a (TSI-Chl-a) is generally considered the most reliable indicator of trophic status, followed by Secchi disk (TSI-SDD), and total phosphorus (TSI-TP) (Carlson, 1977). Carlson's TSI estimate for chlorophyll a is calculated using the following equation: • Trophic status based on Chlorophyll a (TSI-Chl-a): TSI-Chl-a = 9.81 ln (Chl-a) + 30.60, where Chl-a = chlorophyll a concentrations in μg/L. 56 Phytoplankton Community DWQ routinely collects phytoplankton to evaluate the composition and relative abundance of algae and cyanobacteria. These data are used to identify waterbodies potentially undergoing cultural eutrophication that may negatively impact beneficial uses. Phytoplankton data are used in the Tier II assessment process because they may reflect nutrient availability and nutrient ratios. The observation that a waterbody has a diverse assemblage of diatoms or green algae relative to cyanobacteria or other potentially harmful taxa is used as a line of evidence that the waterbody is supporting its designated uses. In contrast, a phytoplankton assemblage dominated by cyanobacteria may be indicative of eutrophication, an increased potential for harmful algal blooms, and a loss of aquatic biodiversity. Great Salt Lake The Great Salt Lake (GSL) is assigned its own beneficial use class (Class 5) and is further divided into five subclasses (5A–5E) that represent the four main bays (Gilbert, Gunnison, Bear River, and Farmington) and transitional waters (UAC R317-2-6). The only numeric water quality criterion currently applicable to GSL is a selenium bird- egg tissue criterion for Gilbert Bay (Class 5A). The beneficial uses of GSL are protected and assessed by Utah’s narrative water quality standard (UAC R317-2-7.2) in addition to this criterion. The Great Salt Lake Water Quality Strategy outlines the process for monitoring and criteria development for GSL. Gilbert Bay Bird-Egg Tissue Assessment Bird eggs are collected during the nesting season from representative locations within the Gilbert Bay AU or adjacent transitional wetlands (UAC R317-2-6.5). Selenium concentrations from eggs collected each year are assessed against the criterion in UAC R317-2-14. Gilbert Bay’s beneficial use will be identified as impaired if the geometric mean of selenium concentrations from five or more eggs collected in any year exceeds the 12.5 mg/kg criterion. If the geometric mean of selenium concentrations from five or more eggs collected in any year exceeds 9.8 mg/kg dry weight, DWQ will identify Gilbert Bay’s beneficial use as threatened and initiate preliminary TMDL studies to evaluate selenium loading sources. If Gilbert Bay is identified as impaired for selenium, five consecutive nesting seasons meeting selenium criteria will be considered sufficient for delisting the impairment. The Gilbert Bay selenium criterion also includes thresholds below 9.8 mg/kg that trigger management actions (Table 15). DWQ evaluates egg concentrations against these thresholds to inform management decisions, but these thresholds are not used for use attainment determinations in the IR. Eggs are also collected as part of discharge monitoring programs for certain dischargers to GSL. Eggs collected as a part of these programs are specifically intended to characterize discharge outfall conditions and are therefore not relevant to assessing more general GSL conditions. Eggs collected under these programs are only used for evaluating discharge permits and are not used in 303(d) assessment of the GSL AUs. Table 15. Selenium trigger levels and DWQ responses (UAC R317-2-14.2(14)). Se concentration (mg/kg dry weight) DWQ Response < 5.0 Routine monitoring with sufficient intensity to determine if selenium concentrations within the Great Salt Lake ecosystem are increasing 5.0 Increased monitoring to address data gaps, loadings, and areas of uncertainty identified from Great Salt Lake selenium studies 6.4 Initiation of a Level II Antidegradation Review (ADR) by the State for all discharge permit renewals or new discharge permits to Great Salt Lake. The Level II ADR may include an analysis of loading reductions. 57 Se concentration (mg/kg dry weight) DWQ Response 9.8 Aquatic life use declared as threatened. Initiate preliminary TMDL studies to evaluate selenium loading sources. 12.5 Aquatic life use declared as impaired. Formalize and implement TMDL. Toxic Parameter Assessments for All Waters DWQ identifies toxics as all parameters within UAC R317-2-14 that are not defined as conventional parameters (see Table 11 and the Lakes, Reservoirs, and Ponds Assessment section). Data are compared against one or more toxic criteria, depending on the beneficial use, to ensure protection of designated beneficial uses. One daily measurement at each monitoring location is compared to the chronic and/or acute criteria for 303(d) assessment purposes. DWQ targets dissolved metals sample collection in lakes at one meter above the bottom of the deepest site of the waterbody, as this location is the most likely to identify dissolved metal exceedances in a lake. Dissolved metals are also assessed through this method when additional metals data are available for other lake locations or depths. The acute and chronic averaging periods defined in UAC R317-2-14 are not currently applied for 303(d) assessment analysis because monitoring and sampling frequencies are different and more widely spaced than the acute and chronic periods typically defined in this rule. Equation-Based Toxic Parameters A number of toxic criteria are specified as equations rather than specific values (see footnotes in UAC R317- 2-14). The equations include variables of other chemical constituents or water properties that either reduce or magnify the extent to which a toxic is harmful to aquatic life. In order to properly apply the correction factor equations, DWQ uses measured data for the variables in the equation to calculate the appropriate numeric criteria for the sample. In order to calculate the correct criterion for a pollutant-result value, the monitoring location site and date of sample must match for the pollutant of concern and the additional parameter(s) that are needed to complete the equation. In the case where there are missing supplemental data values to apply the equation, the following rules will be applied. • Hardness-dependent toxics: For hardness-dependent criteria where a calcium (Ca) or magnesium (Mg) value is missing and the hardness cannot be calculated, a hardness value reported from the laboratory will be used. Data without a hardness value are removed from assessments. • • Aluminum, chronic only: If either a field pH or calculated or laboratory hardness is missing, the aluminum acute default value of 750 microgram per liter (μg/L) provided in Table 2.14.2 of UAC R317-2 will be applied. Otherwise, the following pH and hardness combination and numeric criteria are applied: a. pH ≥ 7.0 and (calculated or laboratory reported) hardness ≥ 50 parts per million (ppm): 750 μg/L b. pH < 7.0 and (calculated or laboratory reported) hardness ≥ 50 ppm: 87 μg/L c. pH ≥ 7.0 and (calculated or laboratory reported) hardness < 50 ppm: 87 μg/L d. pH < 7.0 and (calculated or laboratory reported) hardness < 50 ppm: 87 μg/L • Ammonia, chronic: DWQ assumes fish early life stages are present at all monitoring locations. The following equation is used: ((0.0577/(1+10^(7.688-pH))) + (2.487/(1+ 10^(pH-7.688)))) * MIN (2.85, 1.45*10^(0.028*(25-T))).Where (1.45*10^(0.028*(25-T))) is ≤ 2.85, (1.45*10^(0.028*(25-T))) is applied and if (1.45*100.028*(25-T)) is > 2.85, 2.85 is applied. However, if a field pH or temperature reading is unavailable, a correction factor cannot be made and the result value for ammonia will be removed from the 58 assessment. • Ammonia, acute: If a field pH is missing, a correction factor cannot be made, and the result value for ammonia will be removed from the assessment. Assessment Process Once chronic and acute criteria are calculated, toxicant sampling results, where applicable, are compared to the criteria to determine if the monitoring location is supporting beneficial uses or is impaired due to exceedances of the standard. Sites with sufficient data (four or more samples) with two or more exceedances of the acute and/or chronic criteria will result in non-support of the beneficial use. Four or more samples will be required with one or zero samples exceeding acute or chronic criteria for sites to meet beneficial uses. In cases where there are fewer than four samples, and one or zero samples are exceeding the acute or chronic criteria, sites will be placed in Category 3, insufficient data (Figure 27). Figure 27. Overview of the assessment process for toxic parameters. 59 Data Preparation Following a credible data review and additional QA/QC checks as outlined in DWQ’s Quality Assurance Program Plan for Environmental Data Operations (DWQ, 2014), DWQ compiles all credible data within the period of record of concern and makes several adjustments based on the reported limits and sampling frequencies necessary to conduct the assessment. Similar to the other QA/QC and assessment procedures outlined in this document, the raw data and accompanying metadata values in Escherichia coli (E. coli) datasets are not altered. Instead, DWQ uses a series of database comments and flags. Recreation Season To ensure protection of recreation uses, E. coli assessments will be conducted on data collected during the recreation season from May 1 through October 31. The recreation season may be adjusted to be either longer or shorter based on site-specific conditions. Any site-specific adjustments made to the recreation season will be documented. Escherichia coli Collection Events and Replicate Samples Datasets at a single monitoring location may contain replicate samples or multiple samples collected in the same day due to sampling design. Single daily values or collection events are required for E. coli assessments. DWQ defines a collection event as one of the following: • The daily most probable number (MPN) result value • A geometric mean of replicates where multiple samples are collected on the same day • The daily MPN as a quantified value reported as being obtained from a dilution In cases where replicate samples were taken and there is 1) a quantified MPN value reported from a dilution and 2) the MPN value reported is greater-than-detect, the quantified MPN value will be used as the collection event for assessment purposes. In this scenario, MPNs reported as greater-than-detect are not used to calculate the geometric mean for the collection event. Data Substitution for Calculating the Geometric Mean Assessments use the geometric mean of representative samples to determine if E. coli standards are met. E. coli data that are reported as less- than-detect (< 1) or 0 will be treated as a value of 1 to allow for the calculation of a geometric mean. Similarly, E. coli data that are reported as greater-than-detect (> 2,419.6) will be treated as 2,420 to allow for the calculation of the geometric mean. Use Designation DWQ assesses use support for each monitoring location once the data are compiled. All waters of the state are classified for contact recreation (Class 2), and some waters are classified as drinking water sources (Class 1C). These uses have specific associated E. coli standards that are used to determine use support. The numeric criteria within UAC R317-2-14 are applied to Class 2 and Class 1C uses based on the beneficial use assignments to a waterbody or segment within a waterbody. 60 Assessment Process Annual Recreation Season Assessment DWQ begins the assessment process by gathering information on health advisories and/or closures issued during the recreation season. If a waterbody had two or more E. coli–related beach closures and/or health advisories in a recreation season, or if a health advisory and/or closure was issued for recreational access to a waterbody for two or more weeks, the waterbody is considered impaired and no further assessment is conducted (Figure 17). If there were fewer than two closures or advisories, or if the closure lasted less than two weeks, the assessment process continues using E. coli concentrations. Figure 17. Considering E. coli-related beach closures and/or health advisories. 61 To ensure protection of recreation and drinking water uses of assessed waterbodies of the state, DWQ considers three scenarios based on sampling frequency and the number of collection events at a monitoring location: • Scenario A: A seasonal assessment against the maximum criterion (Figure 18) • Scenario B: A 30-day geometric mean assessment (Figure 19) • Scenario C: A seasonal geometric mean assessment (Figure 20) Scenario A If there are greater than or equal to five collection events spaced 48 hours or more apart within a recreation season, then all collection events within the recreation season are used to make an assessment (see Figure 18). • DWQ does not make impairment decisions based on one exceedance. If the monitoring location has less than 10 collection events within a recreation season, then one collection event may exceed the numeric criterion and the site will still be considered in Scenarios B and C. If two or more collection events exceed the numeric criterion, then the monitoring location is not supporting the beneficial use, and the next beneficial use is assessed. • If there are 10 or more collection events within a recreation season, a percent exceedance is calculated by dividing the number of collection events that exceed the maximum criterion by the total number of collection events. If the calculated percentage is 10% or less, the monitoring location is then assessed using Scenarios B and C. If the calculated percentage is greater than 10%, the monitoring location is not supporting its beneficial use, and the next beneficial use is assessed. • If there are less than five collection events spaced 48 hours or more apart within a recreation season, then the monitoring location is placed in the insufficient data category. • If one or more collection events exceed the maximum criterion, then the monitoring location is placed in the insufficient data with exceedances category. • If no collection events exceed the maximum criterion, then the monitoring location is placed in the insufficient data, no exceedances category. 62 Figure 18. Scenario A: A seasonal assessment using the maximum criterion at a monitoring location. Scenario B If the site’s calculated percent exceedance of the maximum criterion is less than or equal to 10% or no more than 1 sample exceeding the maximum criterion in the case of a dataset with 5 to 9 samples, the site is then assessed using the 30-day geometric mean criterion (see Figure 19). There must be a minimum of five collection events in 30 days with at least 48 hours between collection events in order to assess against the 30-day geometric mean criterion directly. This ensures that collection events are adequately spaced and are representative of ambient conditions. Step 1: Determine if there are ≥5 collection events within a 30-day period. • Count the number of collection events collected between each sample date (day 1) and the sample date plus 29 days (day 30). Step 2: Determine if the collection events are representative (must have ≥5 collection events within a 30-day period). • Count the number of collection events collected between each sample day (day 0) and the sample date plus 2 days (day 3). • If there are two collection events within this period, only one sample will be considered representative. 63 Step 3: Calculate the 30-day geometric mean. • If there are ≥5 representative samples in a 30-day period, then all collection events will be used to calculate the 30-day geometric mean. • If ≥1 30-day geometric mean exceeds the 30-day criteria, the site is not supporting beneficial uses. If there are not representative data for Scenario B, or if the 30-day geometric mean did not exceed the 30-day criteria, the site is assessed using Scenario C. Figure 19. Scenario B: An assessment using the 30-day geometric mean for monitoring locations with five or more collection events within 30 days. Scenario C If adequate (at least five samples) and/or representative data spaced by at least 48 hours are not available to assess against the 30-day geometric mean, DWQ will assess E. coli data for the recreation season, provided there are at least five collection events during the defined recreational season. Exceedances of the geometric mean criterion will result in the site being classified either as impaired (minimum of 10 collection events in a recreation season) or as insufficient data (sample size is more than five but fewer than 10) (see Figure 20). 64 Figure 20. Scenario C: A seasonal geometric mean assessment. Summarizing Assessment Results When determining beneficial use support of a monitoring location with assessment results across multiple years, the following rules are applied, in the following order: Not Supporting (Category 5) • A waterbody has two or more posted health advisories or beach closures during any recreation season. • Any monitoring location with five to nine collection events and two or more collection events that exceed the maximum criterion. • Any monitoring location where the calculated percent exceedance of the maximum criterion within a recreation season for E. coli concentrations is greater than 10% for 10 or more collection events. • Any monitoring location where the 30-day geometric mean exceeds the 30-day geometric mean criterion (minimum five collection events with at least 48 hours between collection events). • Any monitoring location where the recreational season geometric mean exceeds the 30-day geometric mean criterion (minimum of 10 collection events). Insufficient Data 65 • Sites with nine or fewer samples that could not be fully assessed in Scenarios A, B, or C will be listed as insufficient data, provided impairment is not suggested by a posted health advisories or beach closures. Combinations of Category 3 (with no exceedances), 2, and/or 1 • If there is no evidence of impairment at a site by any of the assessment approaches over the period of record, the assessment analysis from the most recent year outweighs the results from previous years. DWQ’s process for merging assessment results from multiple locations within an AU is discussed in more detail in Determinations of Impairment: All Assessment Units. Supporting (Category 1 or 2) • No evidence of impairment by any assessment approach for all recreation seasons over period of record. A fully supporting determination can be made with a minimum of five collection events during the recreational season. Combining E. coli with Other Parameter Assessment Results Until the determination of impairment and the review of additional supporting information are completed by reviewers, parameter assessments at an individual monitoring location and results from multiple monitoring locations within the same AU are not summarized and combined (see Determination of Impairment for more details). Pollution Indicator Assessments for All Waters Several parameters and beneficial uses in UAC R317-2 are identified as pollution indicators and have footnotes indicating that further investigations should be conducted when levels are exceeded. To capture this footnote in the assessment process, DWQ reviews preliminary pollution indicator assessments during the Secondary Review process to determine whether pollution indicators demonstrate clear and convincing evidence of supporting or not supporting the beneficial uses assigned to the waterbody in UAC R317-2. Secondary reviews incorporate pollution indicator data into assessment-category determinations and rely on multiple lines of evidence, including pollution indicator thresholds, the presence or absence of other indicator- associated water quality issues, potential pollutant sources, and other site- or watershed-specific knowledge, to determine whether listing or delisting on a pollution indicator parameter is appropriate or whether to prioritize waterbodies for additional monitoring. Narrative Standards for All Waters Utah’s water quality standards contain narrative criteria that protect beneficial uses in addition to the numeric criteria used to perform water quality assessments. The narrative criteria state: It shall be unlawful, and a violation of these rules, for any person to discharge or place any waste or other substance in such a way as will be or may become offensive such as unnatural deposits, floating debris, oil, scum, or other nuisances such as color, odor to taste; or cause conditions which produce undesirable aquatic life or which produce objectionable tastes in edible aquatic organisms; or result in concentration or combinations of substance which produce undesirable physiological responses in desirable resident fish, or other desirable aquatic life, or undesirable human health effect, as determined by bioassay or other tests performed in accordance with standard procedures; or determined by biological assessments in (UAC) Subsection R317-2-7.3. DWQ will apply the narrative criteria to protect human health and aquatic life where evidence exists that 66 human-caused actions have produced any of these undesirable outcomes in a waterbody. Narrative standards may be used to make an impairment determination for drinking-water closures, fish kills, harmful algal blooms (HABs), beach closures for swimming, and health advisories for the consumption of fish. Assessment of E. coli data and associated beach closures to protect human health provide an additional weight of evidence for defining the impairment of recreational uses and is addressed in more detail earlier in this document in the Escherichia Coli Assessment for All Waters section. DWQ will assess a site as impaired for 1C uses if the Utah Division of Drinking Water or a local municipality issues an advisory or closure for a surface drinking water source, unless data show that the problem has been resolved. Fish Kills DWQ requests information on reported fish kills from the Utah Division of Wildlife Resources and other stakeholders. These data are used with water quality data to make final assessment decisions. For example, sites that would generally not be assessed due to small sample sizes may be listed as impaired if fish kills have also been observed in the waterbody. 67 Harmful Algal Blooms (HAB) In fresh waters, HABs are typically composed of cyanobacteria; a phylum of photosynthetic bacteria sometimes called blue-green algae. Recreational exposure to HABs can result in negative human health and aquatic life impacts (EPA 2019). DWQ‘s HAB assessment methods apply to non-benthic HABs occurring in waterbodies with frequent primary contact recreational uses, including those currently designated with 2A uses and those where existing frequent primary contact recreational uses have been documented. Potential impacts of HABs on aquatic life uses are currently addressed through eutrophication-related aspects of general lakes, reservoirs, ponds, flowing surface waters or the State, and canal assessment methods (e.g. dissolved oxygen, pH, and lake Tier II assessments). DWQ‘s HAB assessment methods use two independent indicators to determine beneficial use support: cyanotoxin concentrations and waterbody access or use limitations. DWQ collects samples during HAB events for use in recreational use assessments using DWQ‘s HAB Standard Operating Procedures (SOP, DWQ 2022). DWQ‘s assessment methods rely on EPA‘s recommended criteria for microcystin and cylindrospermopsin (EPA 2019). Thresholds for additional cyanotoxins may continue to be added to the assessment methods as they become available. Table 16. Cyanotoxin thresholds for recreational use assessments based on EPA (2019) guidance. Microcystins magnitude (ug/L) Cylindrospermopsin magnitude (ug/L) Duration Frequency 8 15 1 in 10-day assessment period across a recreational season Not more than 3 excursions* in a recreational season in more than one year over the period of record * An excursion is defined as a 10-day assessment period with any toxin concentration higher than the recommended criteria magnitude. When more than three excursions occur within a recreational season and that pattern reoccurs in more than one year over the IR period of record, it is an indication the water quality has been or is becoming degraded and is not supporting its recreational use. Beneficial Use Supported The beneficial use is fully supported if, over the period of record: Cyanotoxin concentrations have not been identified above recreational use thresholds (Table 16), AND a Warning Advisory, Danger Advisory, or closure has not been issued for recreational access to a waterbody. Beneficial Use Not Supported The beneficial use is not supported if, in representative samples for recreational uses, in two or more years in the period of record: Cyanotoxin concentrations above recreational guidelines (Table 16) have been reported in more than three 10-day assessment periods in a recreational season, OR a Warning Advisory, Danger Advisory, or closure has been issued for recreational access to a waterbody for two or more 2-week periods in a recreational season. Insufficient Data and Information with Exceedances (IR Category 3) The waterbody will be placed in the insufficient data category if: It does not meet either of the Beneficial Use Not Supported criteria (above), but cyanotoxin concentrations exceeded recreational use thresholds (Table 16) in three or fewer 10-day assessment periods in a recreation season, OR a Warning Advisory, Danger Advisory, or closure has been issued for recreational use for less than two 2-week periods. These waterbodies will be prioritized for further sampling and evaluation. Fish Tissue Assessments and Consumption Health Advisories DWQ has collected fish tissue samples for mercury analysis in waterbodies throughout the state since 2000. Consumption advisories have been issued based on the EPA-published ambient water quality criterion for 68 methyl mercury for the protection of people who eat fish and shellfish. This criterion is 0.3 milligram (mg) methylmercury per kilogram (kg) fish tissue wet weight. If all fish (small and large) of the same species at a monitoring location have a mean mercury concentration of > 0.3 mg/kg, additional statistical tests are used to determine if a consumption advisory is necessary. If the mean is < 0.3 mg/kg, no advisory is issued. In several instances, size class advisories have been issued when it is apparent that only the larger size class exceeds the safe consumption criterion. Using a t-test, the p-value is considered for locations with a mean mercury concentration of > 0.3 mg/kg. In hypothesis testing, a p-value is the statistical probability (over repeated measures) that the mean value (or more extreme value) is observed given that the null hypothesis is true. In the case of health advisories, DWQ uses a t-test to evaluate the difference between a mean mercury concentration > 0.3 mg/kg and the expected mercury value of 0.3 mg/kg. In this statistical test, a smaller p-value indicates a lower probability the statistical comparison supports the null hypothesis that mercury concentrations are at an acceptable level. DWQ uses a p-value of 0.05 as a threshold for consum ption health advisories. If a species has a mean of > 0.3 mg/kg and a p-value < 0.05, a consumption advisory is issued. If a species has a mean of > 0.3 mg/kg but a p-value of > 0.05, an advisory is not issued. The consumption advisories are based on long-term consumption; therefore, the mean is the most appropriate and commonly used parameter to estimate exposure. In an effort to control for false negatives, DWQ calculates 95% confidence limits of the mean mercury concentration. If the upper confidence limit is above 0.3 mg/kg, that site is targeted for additional sampling. When an advisory is warranted, DWQ sends the data to the Utah Department of Health toxicologist, who uses the mean mercury concentration to calculate the actual consumption recommendations. Those calculations are based on the following: • Average adult weight: 70 kg (154 pounds). Average adult meal size: 227 grams (8 ounces)/meal • Average child weight: 16 kg (35 pounds). Average child meal size: 113 grams (4 ounces)/meal 69 Consumption amounts are calculated for three target populations: pregnant women and children < 6 years old; women of child-bearing age and children between 6–16 years old; and adult women past child-bearing age and men >16 years old. Mercury Assessment Process The current approach for mercury assessments for aquatic life is different than the consumption advisory process. The assessment is based on the U.S. Food and Drug Administration (FDA) recommended value of 1.0 mg/kg. The FDA set the consumption concentration at 1.0 mg/kg, which correlates to the water column mercury concentration of 0.012 µg/L identified in previous studies by EPA (EPA, 1985). Utah’s water quality standard for mercury is 0.012 µg/L as a four-day average. Therefore, the corresponding fish tissue concentration of 1.0 mg/kg is used for assessment. Beneficial Use Supported (Category 1) • No fish consumption advisories for mercury are in place. • Mean fish tissue mercury concentration for all individuals of the same species at a location is less than 0.3 mg/kg and p-value is < 0.5. Insufficient Data with Exceedances (Category 3) • Fish consumption advisories for mercury are in place, but the mean fish tissue mercury concentration for all individuals of the same species at a location is less than or equal to 1.0 mg/kg. Beneficial Use Not Supported (Category 5) • Fish consumption advisory for mercury is in place. • Mean fish tissue mercury concentration is greater than 1.0 mg/kg. For additional information and the most up-to-date list of consumption advisories, please visit fishadvisories.utah.gov. Determinations of Impairment: All Assessment Units Each use and parameter within a waterbody is assigned a provisional EPA-derived assessment category after the initial assessment of credible data against the numeric criteria in UAC R317-2. To verify the use and parameter-specific assessment results and consolidate the often multiple parameter assessments into one result per waterbody, DWQ must consider the quantity of data and the extent to which such data demonstrate clear and convincing evidence of supporting or not supporting the beneficial uses assigned to the waterbody DWQ considers the following information to determine whether a waterbody is supporting or not supporting its beneficial uses: • Individual assessment of water quality standards at a single site • Independent applicability • Multiple lines of evidence and several levels of secondary reviews 70 Individual Assessment of Water Quality Standards DWQ first considers the individual use and parameter-specific assessment results from the monitoring- location level data to determine whether a waterbody is supporting or not supporting the beneficial uses assigned in UAC R317-2, Each use and parameter assessed for the waterbody is assigned a provisional EPA-derived assessment category. Unless noted in the waterbody-specific data assessment protocols, the assessment policies outlined in this document provide a direct and quantifiable method and documentation of data supporting or not supporting DWQ’s water quality standards versus data and information that are developed using surrogate parameters or indicators. Because individual assessments at a single monitoring location site offer a more direct measure of supporting or not supporting water quality standards in UAC R317-2, DWQ places a greater weight on individual assessment decisions that follow the data assessment protocols in this document. DWQ looks across the multiple parameter-specific assessment results that exist for a location and consolidates the results into a preliminary assessment at the individual site level after review of the individual water quality standard assessments for a beneficial use. DWQ then assigns one EPA-derived assessment decision category as defined in Table 1 to each monitoring location. Conflicting Assessments of Water Quality Standards DWQ applies the policy of independent applicability to address the possibility of conflicting results among different types of data (e.g., biological versus conventionals, toxics versus E.coli) at the site and AU level and goes through a series of considerations to determine if discrepancies are due to • Differences in data quality • Environmental factors such as the application of the water-effects ratio, development of site-specific criteria, revision to numeric criteria in UAC R317-2, or completion of a use attainability analysis Sites with conflicting assessment results may be listed as Category 3 (insufficient data and information). This allows DWQ to examine conflicting lines of evidence when concerns about the quality of independent datasets cannot be resolved through evaluation and documentation of the QA/QC issues that led to acceptance of one dataset and the resulting assessment result. Specific assumptions regarding model applicability applied during the biological assessment process are discussed in the Biological Assessment section. Similarly, if the application of water-effects ratio, justifiable site-specific criteria change, or change in beneficial uses based on a use attainability analysis cannot rectify the difference in the assessment results, then a Category 3 may be warranted. All evaluations of conflicting assessment decisions will be made in consultation with EPA on a case-by-case basis. Aggregation of Site-Specific Assessments to Assessment Unit Categories For reporting purposes, DWQ aggregates all site-specific water quality assessments within an AU to a single assessment category for that AU as described in Table 1. A flowchart describing this process is presented in Figure 21 (see Appendix 3 for additional detail). 71 Figure 21. Process of assigning EPA categories to AUs based on results of monitoring location assessments. Secondary Review DWQ conducts a secondary review of listing determinations after consolidation of all individual assessment results and assignment of preliminary assessment category(s) for an AU, The secondary review process allows DWQ to apply site/waterbody-specific knowledge and additional data quality controls to evaluate the extent to which data used in the preliminary assessment demonstrate clear and convincing evidence of supporting or not supporting the beneficial uses assigned to the waterbody in UAC R317-2-6. DWQ recognizes that input from reviewers during public comment periods, in addition to the internal secondary review process, may provide key information on the data used in listing decisions. To ensure consistency in its use among different professionals, the secondary review process will be applied in a select number of scenarios using a standard set of evaluation guidelines (Appendix 2). If documentation from the secondary review provides sufficient evidence to modify the basis and result of the preliminary assessment, the preliminary assessment decision based on the data assessment procedures outlined in this document will be overwritten. For example, preliminary listings for Category 5, Category 1, or Category 2 waters could be re-assigned as Category 3, insufficient data and information, based on one or more factors outlined in Appendix 2. DWQ will document the original category assignment and a justification for the secondary review to ensure tracking and transparency. 72 Assessment Unit Re-segmentation DWQ may decide it is appropriate to re-segment (i.e. “split”) an existing AU polygon into two or more new AUs rather than aggregate those conflicting assessments into a single AU scale category when site-specific assessments within a single AU conflict. AUs where water quality criterion exceedances are clearly isolated to a relatively small, hydrologically distinct portion of the larger AU may be re-segmented to more accurately reflect that variation in water quality. For example, a large AU with an impairment isolated to a single tributary may be re-segmented into two AUs: one for the impaired tributary and another for the rest of the existing AU. Assessment categories for both AUs are then determined following standard aggregation (Figure 21 and the delisting procedures discussed in the Delistings section). This results in a higher resolution and overall more accurate assessment. DWQ does not consider it appropriate to re-segment an AU when exceedances are observed in multiple locations throughout an AU or where impaired sites are not hydrologically distinct from unimpaired portions of the AU. If after aggregating all of the assessments into one assessment category for an AU, DWQ determines that the supporting or not supporting assessment result decision is not representative of the entire AU, DWQ will investigate further to determine whether the supporting or not supporting decision is widespread or limited to individual portions of the waterbody, such as specific tributaries or reaches. Results from the analysis will be categorized as follows: Entire AU not supporting (Category 5): DWQ will recommend that the AU not be re-segmented and the entire AU be listed as not supporting. When data from multiple sites or tributaries within an AU indicate multiple (or a combination of) sites that do not support beneficial uses (Category 5) and insufficient data with exceedances (Category 3) Not supporting tributaries listed as not supporting (Category 5): DWQ may recommend the AU be re-segmented into two AUs and that only the tributaries with data indicating impairment are listed as not supporting if data from one or more other tributaries indicate a combination of any of the following: • Insufficient Data with Exceedances (Category 3) • No Evidence of Impairments (Category 2) • Supporting (Category 1) • Needs Further Investigations (Category 3) • Insufficient Data with No Exceedances (Category 3) • Not Assessed (Category 3) The rest of the AU will be assigned a category following procedures as outlined in Figure 21. Identifying Causes of Impairments DWQ will determine if the impairment or impairments are driven by pollutants, pollution, unknown, or natural causes once an AU is assigned an EPA assessment category that is representative of conditions in the AU (see Table 1). DWQ will identify causes of impairment by a pollutant with specific numeric water quality criteria identified in UAC R317-2-14. Pollution is a generalized term for causes of water quality impairment that can include multiple pollutants and other factors such as the absence or lack of water, lack of riparian vegetation, and other modifications that affect a waterbody’s ability to support aquatic habitat and other designated uses. With the exception of naturally occurring causes, only one cause will be applied to a not- 73 supporting waterbody and parameter. Procedures on how DWQ identifies the cause of impairments are described in the section below. Pollutants DWQ uses CWA’s definition as a guide to define pollutant-driven impairments (Category 5) as those resulting from the following: … dredged spoil, solid waste, incinerator residue, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials (except those regulated under Atomic Energy Act of 1954, as amended), heat, wrecked or discarded equipment, rock, sand, cellar dirt, and industrial, municipal, and agricultural waste discharged into water. (UAC R317-2) DWQ also includes certain radiological constituents that are regulated under the state’s Water Quality Control Act. For the purpose of the 303(d) list, causes for impairments due to toxic parameters will be identified as the parameter for which there is an impairment. In the case of conventional parameters such as DO, temperature, pH, and biological scores, the cause will be assigned as the parameter that was assessed until a TMDL or pollution prevention plan identifies an alternative cause of the impairment. DWQ will list the waterbody and the not-supporting parameter(s) as impaired for that pollutant (cadmium, iron, etc.) when an impairment for a waterbody or segment within a waterbody is identified as pollutant-driven. Waterbodies that are not supporting their beneficial uses due to pollutant impairments require future development of a TMDL or application of a TMDL alternative. Where DWQ can identify that an impairment was not driven by a pollutant, it may consider whether the not- supporting assessment was driven solely by pollution versus a pollutant or by an unknown cause. DWQ will use CWA’s definition of pollution as a guide when determining if an impairment resulted from “the man-made or man-induced alteration of the chemical, physical, biological, and radiological integrity of water.” Waterbodies with not-supporting parameters that are driven solely by pollution problems do not require the future development of a TMDL and are candidates for a non-pollutant impairment (4C) assessment category. Details on DWQ’s process for using EPA’s 4C assessment category are described in section Category 4C. Unknown Sources For the purpose of the IR, sources of pollution contributing to an impairment will be reported in the 303(d) list to EPA as “unknown” until a TMDL or special study identifies the sources and any additional causes of impairment. Natural Conditions DWQ will retain the not-supporting assessment decision in cases where it or a stakeholder can demonstrate that the natural conditions of the waterbody or segment within a waterbody are the key factors for an impairment(s). However, DWQ’s response to such exceedances differs unless a site-specific standard has been promulgated. Site-specific standards require documentation that demonstrates the extent to which the violations were due to natural conditions. Proposed changes to standards will be developed once this documentation is assembled Please review DWQ’s Standards website for more information on the review and approval process for developing standards and numeric criteria for exceedances caused by naturally occurring conditions. 74 Revising the 303(d) List and Other Categorical Assessments Upon validating the strength and extent of the impairments within a waterbody or segment within a waterbody, DWQ includes newly proposed and previously listed not supporting (Category 5) waterbodies on the updated 303(d) list unless the waterbody or waterbody segment(s) is currently included in the IR’s TMDL-approved (Category 4A), pollution control (Category 4B), non-pollutant impairment (Category 4C), or delisting lists. Details on how and when DWQ will not apply or carry an impaired listing (not supporting, Category 5) forward on DWQ’s 303(d) list are described below. Category 4A DWQ may choose to not list or remove an impaired waterbody or segment within a waterbody on the state’s 303(d) list by calculating the maximum amount of a pollutant that a waterbody can receive while still meeting the state’s water quality standards. This calculation and analysis work must be formalized in a TMDL and go through a thorough internal and external review process. This TMDL must be provided to the public for review and comment, submitted to the Water Quality Board for approval, reviewed by the Legislative Natural Resources, Agriculture, and Environment Interim Committee if implementation costs exceed $10 million or the full State Legislature for approval if implementation costs exceed $100 million, and ultimately to EPA for their approval. Information on DWQ’s process for developing and implementing a TMDL can be found on DWQ’s Watershed Management Program website and EPA’s TMDL 303(d) website. Where DWQ has documentation of a TMDL approved by the Water Quality Board and EPA for an impaired parameter within a not-supporting waterbody or segment within a waterbody, DWQ will override a current or previous not-supporting Category 5 listing decision at the AU level as follows: Whole AU Category 4A, TMDL-approved if: The only impairments within the waterbody or segment within the waterbody are included in the approved TMDL. There are additional impairments within the waterbody or segments within the waterbody that are addressed in a Category 4B demonstration plan (described in section Category 4B and Appendix 4) and are not included in the approved TMDL. If the parameters included in the approved Category 4B demonstration plan are still not supporting or are insufficient data with exceedances in the current assessment cycle, DW Q will indicate that those parameters have an approved Category 4B demonstration plan in place. There are additional impairments within the waterbody or segments within the waterbody that are pollution- driven (Category 4C) and not included in the approved TMDL. DWQ will indicate that those parameters are pollution versus pollutant driven if the pollution-driven parameters are still not supporting or are insufficient data with exceedances in the current assessment cycle. Whole AU Category 5, Not Supporting if: There are any additional pollutant impairments within the waterbody or segments within the waterbody that are not included in the approved TMDL. DWQ will indicate that those parameters have an approved TMDL in place if the parameters included in the approved TMDL are still not supporting or are insufficient data with exceedances in the current assessment cycle. 75 Category 4B DWQ may choose to not list or remove an impaired waterbody or segment within a waterbody on the state’s 303(d) list by developing a plan that ensures, upon implementation, that the waterbody will meet state water quality standards within a reasonable time period and through state- and EPA-approved pollution-control mechanisms. Similar to a TMDL, a Category 4B demonstration plan must go through a robust internal and external review process. Once DWQ or a stakeholder develops a plan for consideration, DWQ will present the plan to the Water Quality Board and submit the board-approved plan to EPA for final approval. More information on the Category 4B demonstration plan process can be found in Appendix 4 and in EPA’s Category 4b – A Regulatory Alternative to TMDLs document. Where DWQ has documentation of an EPA-approved Category 4B demonstration plan for an impaired parameter within a not-supporting waterbody or segment within a waterbody, DWQ will override a current (or previous) not-supporting Category 5 listing decision at the AU level as follows: Whole AU Category 4A, TMDL-approved if: There are any additional impairments within the waterbody or segments within the waterbody that are addressed in an approved TMDL (Category 4A) and are not included in the approved Category 4B demonstration plan. DWQ will indicate that those parameters have an approved Category 4B demonstration plan in place if the parameters included in the approved Category 4B demonstration plan are still not supporting or are insufficient data with exceedances in the current assessment cycle. Whole AU Category 4B, Pollution Control if: The only impairments within the waterbody or segment within the waterbody are included in the approved Category 4B demonstration plan. There are additional impairments within the waterbody or segments within the waterbody that are pollution driven (Category 4C) and are not included in the approved Category 4B demonstration plan. DWQ will indicate that those parameters are pollution rather than pollutant driven if the pollution-driven parameter impairments are still not supporting or are insufficient data with exceedances in the current assessment cycle. Whole AU Category 5, Not Supporting if: There are any additional pollutant impairments within the waterbody or segments within the waterbody that are not included in the approved Category 4B demonstration plan. DWQ will indicate that those parameters have an approved Category 4B demonstration plan in place if the parameters included in the approved Category 4B demonstration plan are still not supporting or are insufficient data with exceedances in the current assessment cycle. Category 4C DWQ may choose to not list or remove an impaired waterbody or segment within a waterbody on the state’s 303(d) List when DWQ can demonstrate that the parameter-specific impairment (or impairments) is driven by pollution and not by a pollutant or pollutant that causes pollution; for example, an impairment driven by hydrologic modification or habitat degradation. Unlike a TMDL or Category 4B demonstration plan, the analysis determines if the cause of impairment is driven by pollution and does not require formal approval from the Water Quality Board or EPA. The determination is reviewed internally by DWQ and by stakeholders during the public comment period of the draft IR and 303(d) list. For the draft IR and 303(d) list, DWQ will temporarily assume “approval” of any pollution-driven analysis work and supersede a current or previous not supporting Category 5 listing decision at the AU level as follows: 76 Whole AU Category 4A, TMDL-approved if: All impairments within the waterbody or segments within the waterbody are addressed in an approved TMDL (Category 4A). DWQ will indicate that those parameters are pollution- rather than pollutant-driven for pollution-driven impairments that are still not supporting or are insufficient data with exceedances in the current assessment cycle. Whole AU Category 4B, Pollution Control if: All impairments within the waterbody or segments within the waterbody are addressed in an approved Category 4B demonstration plan. DWQ will indicate that those parameters are pollution driven for pollution- driven impairments that are still not supporting or are insufficient data with exceedances in the current assessment cycle. Whole AU Category 4C, Non-Pollutant Impairment if: The only impairments within the waterbody or segment within the waterbody are included in the approved Category 4C demonstration plan. Whole AU Category 5, Not Supporting if: There are any additional pollutant impairments within the waterbody or segments within the waterbody. DWQ will indicate that those parameters are pollution-driven for pollution-driven impairments that are still not supporting or are insufficient data with exceedances in the current assessment cycle. DWQ will provide stakeholders with draft IR and 303(d) list documentation during the public comment period to demonstrate why the impaired parameter within the waterbody or segment within the waterbody is pollution- and not pollutant-driven and will not require the future development of a TMDL. Delistings The fourth and final alternative DWQ has at its disposal is to demonstrate good cause to stakeholders and EPA that a previously impaired parameter and waterbody or segment within a waterbody is now meeting water quality standards in UAC R317-2. Good cause occurs when DWQ can demonstrate one or more of the following categories and scenarios: Meeting water quality criteria due to restoration activities The waterbody has improved due to implementation of nonpoint source projects and/or revised effluent limits and post-implementation data indicate that the impairment has been resolved. This assessment may be based on additional data beyond that which is typically used in assessments, including before–and-after project implementation monitoring. In some cases, demonstration of improvement may be based on a different time period for data collection that corresponds with known watershed improvements. Applicable water quality standard attained due to change in water quality standard Adoption of revised water quality standards and/or uses so the waterbody now meets the revised standards and/or uses. Applicable water quality standard attained due to change in 303(d) assessment methods Development of a new listing method consistent with the state water quality standards and classifications and federal listing requirements. This includes all information contained in this document and posted on DWQ’s Call for Data webpages. 77 Meeting water quality criteria with new data Assessment and interpretation of older data that was not originally included in the previous assessment and/or more recent or more accurate data that demonstrate that the applicable classified uses and numeric and narrative standards are being met. Listed water not in state's jurisdiction Inappropriate listing of a water that is located within Indian country as defined in 18 United States Code 1151. Original basis for listing was incorrect Flaws in the original analysis of data and information that led to the waterbody-pollutant combination being incorrectly listed. Such flaws may include the following: (1) calculation errors in the data assessment methods outlined in the 303(d) assessment methods from that assessment cycle; (2) errors produced when reviewing credible and representative data information; (3) mapping errors generated during the validation of monitoring location information and assigning AU designations; (4) discrepancies between the beneficial use assignments in UAC R317-2 and the IR geo-location information files for internal and external data; (5), incorrect identification and assessment of a waterbody type; and (6) application of the wrong numeric criteria to a beneficial use. New modeling Results of more sophisticated water quality modeling that demonstrate that the applicable classified uses and numeric and narrative standards are being met. Effluent limitations Demonstration pursuant to 40 CFR 130.7(b)(1)(ii) that there are effluent limitations required by state or local authorities that are more stringent than technology-based effluent limitations required by the CWA and that these more stringent effluent limitations will result in support of classified uses and numeric and narrative standards for the pollutant causing the impairment. Other There is other relevant information that supports the decision not to include the segment on the Section 303(d) list. In order to justify a delisting of an AU for a given parameter based on new data, the dataset must be of sufficient quantity and quality to make an assessment. There are two mechanisms for justifying a delisting based on assessment results: • Delisting an AU for all parameters • Delisting individual parameters for an AU DWQ will compare the previous IR cycle’s final assessment categories and 303(d) list to the current IR’s assessment categories and 303(d) list to demonstrate good cause. Where differences in categorical assignments exist, DWQ will only further investigate the following scenarios for good cause: • The AU/waterbody or segment within the waterbody was previously not supporting (Category 5) and is now supporting (Category 1) or shows no evidence of impairment (Category 2). • The AU/waterbody or segment within the waterbody was previously not supporting but had an approved TMDL (Category 4A) and is now supporting (Category 1) or shows no evidence of impairment (Category 2). 78 • The AU/waterbody or segment within the waterbody was previously not supporting but had an approved Category 4B demonstration plan and is now supporting (Category 1) or shows no evidence of impairment (Category 2). • The AU/waterbody or segment within the waterbody was previously not supporting but had pollution- driven impairment (Category 4C) and is now supporting (Category 1) or shows no evidence of impairment (Category 2). Note: The next set of scenarios describes the methods that apply to delisting individual parameters rather than entire AUs. • A parameter within an AU/waterbody (or segment within the waterbody) was previously not supporting (Category 5) and is now supporting (Category 1) or shows no evidence of impairment (Category 2). • A parameter within an AU/waterbody (or segment within the waterbody) was previously not supporting but had an approved TMDL (Category 4A) and is now supporting (Category 1) or shows no evidence of impairment (Category 2). • A parameter within an AU/waterbody (or segment within the waterbody) was previously not supporting but had an approved Category 4B demonstration plan and is now supporting (Category 1) or shows no evidence of impairment (Category 2). • A parameter within an AU/waterbody (or segment within the waterbody) was previously not supporting but had pollution-driven impairment (Category 4C) and is now supporting (Category 1) or shows no evidence of impairment (Category 2). Where assessment category assignments at the AU- and parameter-level warrant a further investigation for good cause, DWQ will reevaluate the data using the following: • The period of record from when the AU and/or parameter was first listed • The period of record in the current assessment cycle • The data that were collected between when the AU and/or parameter were first listed and the period of record considered in the current assessment cycle DWQ will review the data from all assessed sample locations (as defined in Table 4) in the three above scenarios as part of the demonstration-of-good-cause process to confirm whether there were exceedances at the sample sites. DWQ must demonstrate that the exceedances no longer exist, no longer are of concern, or that water quality has improved. DWQ will provide documentation and a justification as to why the site was not re-sampled and/or whether water quality conditions have improved if a sample site had exceedances and newer data do not exist. If documentation cannot be provided, the AU and parameter will not be delisted, and the previous categorical assignment will carry forward. Delisting Categorical Pollutant Causes When TMDLs or special studies identify parameters contributing to a cause of impairment that is not the original cause for listing on the 303(d) list, there may be good cause justification for delisting the categorical cause if the original impaired parameter is no longer impaired and a linkage of the additional causes can be documented in a TMDL or other study. For instance, in some circumstances DWQ has identified phosphorus as a contributing cause of impairment to an existing DO listing and subsequently made a categorical listing for phosphorus as a cause on subsequent 303(d) lists. Since DWQ does not have assessment methods for phosphorus, a delisting based on the process outlined here is not feasible. Therefore, if the assessment results for the original DO listing can justify a delisting, any additional parameters associated with that cause may also be delisted with proper documentation of a direct linkage. 79 Appendix 5 elaborates on the process DWQ will follow when evaluating good cause at the AU-level and also describes, in more detail, the process DWQ will go through when evaluating good cause at the parameter level. DWQ applies several delisting codes for EPA review and approval (also included in Appendix 5 ). If a waterbody or parameter is shown to have good cause for not being listed or removed as an impaired waterbody or segment within a waterbody on the state’s 303(d) list, DWQ will state the good cause and provide a detailed description of the good cause. Details of the good-cause evaluation process, such as the data-analysis work, will not be posted online during the draft public comment period or after the final approval and publication of the final IR and 303(d) list. DWQ will, however, summarize the data analysis work in the description of the good cause. The analyses will be available to the public upon request through Utah’s Government Records Access and Management Act (GRAMA) process. Previous Categorical Listings 303(d) Listings DWQ must continue to list all previous impairments absent proper documentation to support changing a previous not-supporting (Category 5) listing decision to a TMDL-approved (Category 4A), pollution control (Category 4B), non-pollutant impairment (Category 4C), or delisting (demonstration of good cause). At a minimum, this includes carrying forward all waterbodies or segments within a waterbody that were previously not supporting (Category 5), indicating the cause of impairment, listing the beneficial use or uses failing to meet water quality standards, providing the priority of developing a TMDL, and indicating the assessment cycle the waterbody or segment within the waterbody was first listed. Non-303(d) Categorical Listings Where DWQ has the proper documentation to support changing a previous not-supporting (Category 5) listing decision to a TMDL-approved (Category 4A), pollution control (Category 4B), non-pollutant impairment (Category 4C), or delisting (demonstration of good cause), it will do so as outlined by the policies and procedure described throughout this document. DWQ will also carry forward all previous categorizations of waterbodies or segments within a waterbody if the waterbody does not have any credible or representative data from the period of record of the current assessment cycle. This includes carrying the following forward: • Previous TMDL-approved (Category 4A), pollution control (Category 4B), and non-pollutant impairment (Category 4C) categorizations that do not demonstrate good cause. • Previous categorizations that have insufficient data with exceedances (Category 3), require further investigations (Category 3), have insufficient data with no exceedances (Category 3), are not assessed (Category 3), show no evidence of impairment (Category 2), or are supporting (Category 1). • Historical Category 3 waters that had insufficient data with exceedances will remain in that category unless there is new data for assessment. Waterbodies or segments within a waterbody that are supporting or show no evidence of impairment (Categories 1 and 2, respectively) may carry forward for six consecutive assessment (or two rotating basin) cycles. On the seventh consecutive assessment cycle, DWQ will no longer carry forward a supporting or no evidence of impairment categorization for waterbodies or segment within a waterbody that do not have any new data collected in the last 12 years. Data older than the period of record may not be reflective of current conditions and will not be used for assessment purposes unless there is information or a rationale with supporting documentation that shows the data are reflective of current conditions. 80 If there is evidence that the data are reflective of current conditions, the previous supporting (Category 1) or no evidence of impairment (Category 2) categorization will carry forward for one more assessment cycle (the current one) and be re-evaluated in the next cycle. DWQ will not carry forward the supporting or no evidence of impairment categorization for a seventh consecutive assessment cycle if there is no (or not enough) supporting evidence that the data are reflective of current conditions. DWQ will instead change the categorization to insufficient data with no exceedances (Category 3). 303(d) Vision and TMDL Priority Development DWQ must ensure that TMDLs will be developed following the final release of the current IR and 303(d) list for waterbodies or segments within a waterbody that are impaired by a pollutant. Recognizing that all TMDLs cannot be completed at once and that certain risks may be greater than others, CWA Section 303(d) allows states to prioritize impaired waterbodies or segments within a waterbody on the Section 303(d) list for the future development of TMDLs. On December 5, 2013, EPA announced a collaborative framework for implementing the CWA Section 303(d) program to help guide states on how to best prioritize TMDL development and demonstrate progress on addressing the water quality concerns highlighted and reported on in the IR and 303(d) list (See A Long-Term Vision for Assessment, Restoration, and Protection under the Clean Water Act Section 303(d) Program). This EPA document provided a framework that states could use to optimize their resources when developing TMDLs and other water quality improvement programs such as the anti-degradation program, nonpoint source implementation program, and the 401 water quality certification program. As a result, DWQ prioritized TMDL development for impairments/pollutants that pose the greatest risk to human and ecological health as described in the Division of Water Quality's (DWQ) 303(d) vision document. These priorities translate into the protection and restoration of waters designated for culinary, recreational, and aquatic life uses. Considerations for TMDL prioritization in Utah included partner agencies and stakeholder involvement and the potential for restoration. Other factors considered in setting TMDL priorities include programmatic needs such as permitting and addressing watershed-wide water quality issues. For the IR and 303(d) reporting-specific elements, DWQ: • Assigns TMDL priorities to impaired waterbodies and segments within waterbodies on DWQ’s 303(d) list • Tracks the status and development of TMDLs Revision Requests between Cycles DWQ will, barring unforeseen circumstances, only propose to revise the IR and 303(d) list during the regularly scheduled reviews, which are currently biennially and on even-numbered years. Interested persons may petition DWQ at any time to request a revision to the IR and 303(d) list, whether it is an addition or deletion to the final 303(d) list. DWQ will take the potential revision under strong consideration and begin a dialogue with the interested part or parties and EPA. 81 Literature Cited Carlson, R.E. 1977. A Trophic Status Index for Lakes. Limnology and Oceanography 22:361–364. Carlson, R.E., and K.E. Havens. 2005. Simple graphical method for interpretation of relationships between trophic state variables. Lake and Reservoir Management 21:107-118. EPA. 2016. Human health recreational ambient water quality criteria or swimming advisories for Microcystins and Cylindrospermopsin. Hawkins, C.P., 2006. Quantifying biological integrity by taxonomic completeness: its utility in regional and global assessments. Ecological Applications, 16(4), pp.1277-1294. Hawkins, C.P., Olson, J.R. and Hill, R.A., 2010. The reference condition: predicting benchmarks for ecological and water-quality assessments. Journal of the North American Benthological Society, 29(1), pp.312-343. Hawkins, C.P., Cao, Y. and Roper, B., 2010. Method of predicting reference condition biota affects the performance and interpretation of ecological indices. Freshwater Biology, 55(5), pp.1066-1085. Hughes, R.M., D.P. Larsen, and J.M. Omernik. 1986. Regional reference sites: a method for assessing stream potential. Environmental Management 5:629–635. Lévesque, B., M. Gervais, P. Chevalier, D. Gauvin, E. Anassour-laouan-sidi, S. Gingras, N. Fortin, G. Brisson, C. Greer, and D. Bird. 2014. Science of the Total Environment Prospective study of acute health effects in relation to exposure to cyanobacteria. Science of the Total Environment 466-467:397–403. Lin, C. J., T. J. Wade, E. A. Sams, A. P. Dufour, A. D. Chapman, and E. D. Hilborn. 2016. A Prospective Study of Marine Phytoplankton and Reported Illness among Recreational Beachgoers in Puerto Rico, 2009. Ostermiller, J. D., M. Shupryt, M. A. Baker, B. Neilson, E. B. Gaddis, A. J. Hobson, B. Marshall, T Miller, D. Richards, N. vonStackelberg. 2014. Technical Basis for Utah’s Nutrient Strategy, Draft Report. Utah Division of Water Quality. Suplee, M., R. Sada de Suplee, D. Feldman, and T. Laidlaw. 2005. Identification and Assessment of Montana Reference Streams: A Follow-Up and Expansion of the 1992 Benchmark Biology Study. Helena, Montana: Montana Department of Environmental Quality. U.S. Environmental Protection Agency (EPA). 2019. Recommended Human Health Recreational Ambient Water Quality Criteria or Swimming Advisories for Microcystins and Cylindrospermopsin. EPA 822-R-19-001. Available at https://www.epa.gov/sites/default/files/2019-05/documents/hh-rec-criteria-habs-document- 2019.pdf U.S. Environmental Protection Agency (EPA). 1985. Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and their Uses. EPA-PB85-227049. U.S. Environmental Protection Agency. EPA Requirements for Quality Assurance Project Plans. Office of Environmental Information. Washington: March 2002. (EPA/240/B-01/003). U.S. Environmental Protection Agency. Sampling Analysis Plan Guidance and Template, Version 4, General Projects. Washington: May 2014. (EPA R9QA/009.1). U.S. Environmental Protection Agency. 2005. Guidance for 2006 assessment, listing and reporting requirements pursuant to Sections 303(d) and 305(b) of the Clean Water Act. Available at: https://www.epa.gov/sites/default/files/2015-10/documents/2006irg-report.pdf. Accessed October 13, 2022. 82 U.S. Geological Survey (USGS). 2006. Guidelines and Standard Procedures for Continuous Water-Quality Monitors: Station Operation, Record Computation, and Data Reporting. Available at: http://pubs.usgs.gov/tm/2006/tm1D3/pdf/TM1D3.pdf. Accessed October 13, 2022. Utah Division of Water Quality (DWQ). 2022. Sample Analysis Plan for Sample Collection and Identification of Harmful Algal Blooms. Available at https://documents.deq.utah.gov/water-quality/monitoring- reporting/sop/DWQ- 2022-007511.pdf Utah Division of Water Quality (DWQ). 2014. Quality Assurance Program Plan For Environmental Data Operations. Final Plan. Available at: https://documents.deq.utah.gov/water-quality/monitoring- reporting/sop/DWQ-2019-001869.pdf. Accessed October 13, 2022. Wright, J.F. 1995. Development and use of a system for predicting the macroinvertebrate fauna in flowing waters. Australian Journal of Ecology 20:181–197. Chapter 2 Assessments Specific to Lakes, Reservoirs, and Ponds Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment Unit AU Water Quality Cycle First 303(d) Management Unit (AU) ID AU Name Water Size Unit Category Category Description Parameter Parameter Status 303(d) Status Use(s) Listed Priority Bear River UT-L-16010201-003_00 Bear Lake 35414.5 Acres 1 Fully Supporting Bear River UT-L-16010101-002_00 Birch Creek 61.6 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Bear River UT-L-16010202-002_00 Cutler Reservoir 1356.1 Acres 4A Approved TMDL Eutrophication Not meeting criteria TMDL Approved (38237) Aquatic Wildlife (Warm Water) 2004 Low Minimum Dissolved Oxygen Meeting criteria TMDL Approved (38237) Aquatic Wildlife (Warm Water) Total Phosphorus as P Not meeting criteria TMDL Approved (38237) Aquatic Wildlife (Warm Water) 2004 Low Bear River UT-L-16010203-005_00 Hyrum Reservoir 445.6 Acres 4A Approved TMDL Minimum Dissolved Oxygen Meeting criteria TMDL Approved (4011) Aquatic Wildlife (Cold Water) Total Phosphorus as P Not meeting criteria TMDL Approved (4011) Aquatic Wildlife (Cold Water) 1998 Low Bear River UT-L-16010101-007_00 Little Creek Reservoir 67.2 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Bear River UT-L-16010204-033_00 Mantua Reservoir 513.8 Acres 5 Not Supporting but has Approved TMDL for some parameters Harmful algal blooms Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (762) Aquatic Wildlife (Cold Water) 1998 Low pH Meeting criteria TMDL Approved (762) Aquatic Wildlife (Cold Water) Total Phosphorus as P Not meeting criteria TMDL Approved (762) Aquatic Wildlife (Cold Water) 1998 Low Bear River UT-L-16010202-013_00 Newton Reservoir 171.8 Acres 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2006 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (11148) Aquatic Wildlife (Cold Water) 1998 Low Total Phosphorus as P Not meeting criteria TMDL Approved (11148) Aquatic Wildlife (Cold Water) 1998 Low Bear River UT-L-16010203-009_00 Porcupine Reservoir 180.2 Acres 2 No Evidence of Impairment Bear River UT-L-16010203-012_00 Tony Grove Lake 25.1 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2006 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1996 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2004 Low Bear River UT-L-16010101-030_00 Whitney Reservoir 129.3 Acres 2 No Evidence of Impairment Bear River UT-L-16010101-001_00 Woodruff Reservoir 92.1 Acres 2 No Evidence of Impairment Cedar-Beaver UT-L-16030007-024_00 Anderson Meadow Reservoir 7.8 Acres 2 No Evidence of Impairment Cedar-Beaver UT-L-16030007-020_00 Kents Lake 38.9 Acres 5 Not Supporting but has Approved TMDL for some parameters Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (601) Aquatic Wildlife (Cold Water) 1998 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Total Phosphorus as P Not meeting criteria TMDL Approved (601) Aquatic Wildlife (Cold Water) 1998 Low Cedar-Beaver UT-L-16030007-027_00 LaBaron Lake 21.6 Acres 4A Approved TMDL Minimum Dissolved Oxygen Meeting criteria TMDL Approved (610) Aquatic Wildlife (Cold Water) Total Phosphorus as P Not meeting criteria TMDL Approved (610) Aquatic Wildlife (Cold Water) 2014 Low Cedar-Beaver UT-L-16030007-011_00 Minersville Reservoir 1070.7 Acres 4A Approved TMDL Temperature Not meeting criteria TMDL Approved (808) Aquatic Wildlife (Cold Water) 1994 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (808) Aquatic Wildlife (Cold Water) 1998 Low pH Not meeting criteria TMDL Approved (808) Aquatic Wildlife (Cold Water) 2014 Low Total Phosphorus as P Not meeting criteria TMDL Approved (808) Aquatic Wildlife (Cold Water) 1998 Low Cedar-Beaver UT-L-16030006-008_00 Newcastle Reservoir 158.8 Acres 5 Not Supporting but has Approved TMDL for some parameters Fish Tissue (Mercury) Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2010 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2012 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (35080) Aquatic Wildlife (Cold Water) 1996 Low pH Not meeting criteria TMDL Approved (35080) Aquatic Wildlife (Cold Water) 2022 Low Total Phosphorus as P Not meeting criteria TMDL Approved (35080) Aquatic Wildlife (Cold Water) 1996 Low Cedar-Beaver UT-L-16030007-028_00 Puffer Lake 58.0 Acres 4A Approved TMDL Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (964) Aquatic Wildlife (Cold Water) 1998 Low pH Not meeting criteria TMDL Approved (964) Aquatic Wildlife (Cold Water) 2014 Low Cedar-Beaver UT-L-16030006-019_00 Red Creek Reservoir (Iron Co) 59.0 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Total Phosphorus as P Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2006 Low Cedar-Beaver UT-L-16030007-025_00 Three Creeks Reservoir 55.1 Acres 5 Not Supporting pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2006 Low Cedar-Beaver UT-L-16030006-002_00 Upper Enterprise Reservoir 352.8 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2012 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Cedar-Beaver UT-L-16030006-017_00 Yankee Meadow Reservoir 56.1 Acres 5 Not Supporting pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Great Salt Lake UT-L-16020310-003_00 Bear River Bay 71681.3 Acres 3 Insufficient Data Great Salt Lake UT-L-16020310-004_00 Farmington Bay 77243.2 Acres 3 Insufficient Data Great Salt Lake UT-L-16020310-001_00 Gilbert Bay 559424.0 Acres 2 No Evidence of Impairment Great Salt Lake UT-L-16020310-002_00 Gunnison Bay 384588.2 Acres 3 Insufficient Data Jordan River UT-L-16020204-001_00 Blackridge Reservoir 4.1 Acres 5 Not Supporting Harmful algal blooms Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Jordan River UT-L-16020204-024_00 Lake Mary 19.2 Acres 3 Insufficient Data Jordan River UT-L-16020204-026_00 Little Dell Reservoir 221.0 Acres 2 No Evidence of Impairment Jordan River UT-L-16020201-006_00 Silver Lake Flat Reservoir 32.7 Acres 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Jordan River UT-L-16020201-005_00 Tibble Fork Reservoir 11.2 Acres 2 No Evidence of Impairment Lower Colorado River UT-L-15010008-008_00 Baker Dam Reservoir 44.1 Acres 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1992 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (12105) Aquatic Wildlife (Cold Water) 1998 Low Total Phosphorus as P Not meeting criteria TMDL Approved (12105) Aquatic Wildlife (Cold Water) 2002 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment Unit AU Water Quality Cycle First 303(d) Management Unit (AU) ID AU Name Water Size Unit Category Category Description Parameter Parameter Status 303(d) Status Use(s) Listed Priority Lower Colorado River UT-L-15010008-001_00 Gunlock Reservoir 221.1 Acres 4A Approved TMDL Minimum Dissolved Oxygen Total Phosphorus as P Meeting criteria Not meeting criteria TMDL Approved (12106) TMDL Approved (12106) Aquatic Wildlife (Warm Water) Aquatic Wildlife (Warm Water) 1998 Low Lower Colorado River UT-L-15010008-018_00 Kolob Reservoir 237.9 Acres 2 No Evidence of Impairment Lower Colorado River UT-L-15010008-024_00 Quail Creek Reservoir 587.9 Acres 2 No Evidence of Impairment Lower Colorado River UT-L-15010008-025_00 Sand Hollow Reservoir 1260.3 Acres 2 No Evidence of Impairment Lower Sevier River UT-L-16030003-005_00 Barney Lake 20.6 Acres 3 Insufficient Data Lower Sevier River UT-L-16030005-026_00 D.M.A.D. Reservoir 773.2 Acres 2 No Evidence of Impairment Lower Sevier River UT-L-16030005-021_00 Gunnison Bend Reservoir 497.4 Acres 2 No Evidence of Impairment Lower Sevier River UT-L-16030004-002_00 Gunnison Reservoir 1258.1 Acres 2 No Evidence of Impairment Lower Sevier River UT-L-16030003-006_00 Manning Meadow Reservoir 84.8 Acres 5 Not Supporting Harmful algal blooms Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Total Phosphorus as P Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1994 Low Lower Sevier River UT-L-16030004-001_00 Ninemile Reservoir 184.9 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1998 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Total Phosphorus as P Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1996 Low Lower Sevier River UT-L-16030004-005_00 Palisade Lake 79.6 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1992 Low Lower Sevier River UT-L-16030003-012_00 Redmond Lake 239.9 Acres 2 No Evidence of Impairment Lower Sevier River UT-L-16030003-016_00 Rex Reservoir 34.9 Acres 2 No Evidence of Impairment Lower Sevier River UT-L-16030003-007_00 Sevier Bridge Reservoir (Yuba L 8978.0 Acres 5 Not Supporting Harmful algal blooms Not meeting criteria TMDL Needed Recreation and Aesthetics (Frequent Primary Contact) 2024 Low Southeast Colorado River UT-L-14080201-002_00 Blanding City Reservoir 91.5 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2012 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Southeast Colorado River UT-L-14030004-001_00 Dark Canyon Lake 5.1 Acres 2 No Evidence of Impairment Southeast Colorado River UT-L-14030005-004_00 Kens Lake 77.5 Acres 1 Fully Supporting Southeast Colorado River UT-L-14080203-009_00 Lloyds Reservoir 90.5 Acres 2 No Evidence of Impairment Southeast Colorado River UT-L-14080203-002_00 Monticello Lake 5.5 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2006 Low Southeast Colorado River UT-L-14080201-007_00 Recapture Reservoir 221.0 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Uinta Basin UT-L-14060010-003_00 Ashley Twin Lakes 31.7 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14040106-031_00 Beaver Meadow Reservoir 105.7 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060003-230_00 Big Sand Wash Reservoir 394.5 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14040107-004_00 Bridger Lake 19.3 Acres 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1996 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Uinta Basin UT-L-14060010-002_00 Brough Reservoir 135.9 Acres 5 Not Supporting but has Approved TMDL for some parameters Fish Tissue (Mercury) Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (35100) Aquatic Wildlife (Cold Water) 1998 Low Uinta Basin UT-L-14040106-019_00 Browne Lake 48.1 Acres 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Uinta Basin UT-L-14060003-293_00 Butterfly Lake 4.7 Acres 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Uinta Basin UT-L-14040106-034_00 Calder Reservoir 94.2 Acres 5 Not Supporting but has Approved TMDL for some parameters Eutrophication Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2010 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (33613) Aquatic Wildlife (Cold Water) 1998 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Total Ammonia as N Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Total Phosphorus as P Not meeting criteria TMDL Approved (33613) Aquatic Wildlife (Cold Water) 1998 Low Uinta Basin UT-L-14040107-006_00 China Lake 27.1 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2000 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1996 Low Uinta Basin UT-L-14040106-026_00 Crouse Reservoir 110.9 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060004-007_00 Currant Creek Reservoir 274.4 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060010-007_00 East Park Reservoir 178.6 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14040106-021_00 Flaming Gorge Reservoir 12525.0 Acres 5 Not Supporting pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Uinta Basin UT-L-14040106-001_00 Hoop Lake 171.4 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060003-012_00 Hoover Lake 18.6 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060004-004_00 Lake Canyon Lake 29.2 Acres 5 Not Supporting Arsenic Not meeting criteria TMDL Needed Domestic Source 2016 Low Boron Not meeting criteria TMDL Needed Agricultural 2016 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2016 Low Uinta Basin UT-L-14040106-032_00 Long Park Reservoir 300.6 Acres 2 No Evidence of Impairment Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment Unit AU Water Quality Cycle First 303(d) Management Unit (AU) ID AU Name Water Size Unit Category Category Description Parameter Parameter Status 303(d) Status Use(s) Listed Priority Uinta Basin UT-L-14040107-005_00 Lyman Lake 35.4 Acres 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1996 Low Uinta Basin UT-L-14040107-003_00 Marsh Lake 41.9 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060003-011_00 Marshall Lake 18.8 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14040106-033_00 Matt Warner Reservoir 364.1 Acres 5 Not Supporting but has Approved TMDL for some parameters Eutrophication Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Harmful algal blooms Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1996 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (33618) Aquatic Wildlife (Cold Water) 1998 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Total Phosphorus as P Not meeting criteria TMDL Approved (33618) Aquatic Wildlife (Cold Water) 1998 Low Uinta Basin UT-L-14040107-001_00 Meeks Cabin Reservoir 16.8 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060003-006_00 Mirror Lake 53.5 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060003-112_00 Moon Lake 786.1 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060010-005_00 Oaks Park Reservoir 338.2 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060003-297_00 Paradise Park Reservoir 147.0 Acres 5 Not Supporting pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Uinta Basin UT-L-14060010-001_00 Pelican Lake 1114.4 Acres 5 Not Supporting pH Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2004 Low Total Phosphorus as P Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2012 Low Uinta Basin UT-L-14060003-003_00 Pyramid Lake 14.8 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060004-003_00 Red Creek Reservoir 146.9 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060010-008_00 Red Fleet Reservoir 477.9 Acres 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2010 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (35079) Aquatic Wildlife (Cold Water) 1998 Low Uinta Basin UT-L-14060003-002_00 Scout Lake 19.2 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14040106-016_00 Sheep Creek Lake 81.1 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14040106-002_00 Spirit Lake 42.0 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060004-006_00 Starvation Reservoir 3350.7 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Uinta Basin UT-L-14040107-007_00 Stateline Reservoir 273.7 Acres 2 No Evidence of Impairment Uinta Basin UT-L-14060010-006_00 Steinaker Reservoir 745.2 Acres 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (35078) Aquatic Wildlife (Cold Water) 1998 Low Uinta Basin UT-L-14060010-009_00 Stewart Lake 158.3 Acres 5 Not Supporting Selenium Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2016 Low Uinta Basin UT-L-14060004-001_00 Strawberry Reservoir 15614.2 Acres 5 Not Supporting but has Approved TMDL for some parameters Minimum Dissolved Oxygen Meeting criteria TMDL Approved (33705) Aquatic Wildlife (Cold Water) pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Total Phosphorus as P Not meeting criteria TMDL Approved (33705) Aquatic Wildlife (Cold Water) 1998 Low Uinta Basin UT-L-14060003-296_00 Upper Stillwater Reservoir 300.8 Acres 2 No Evidence of Impairment Upper Provo River UT-L-16020203-001_00 Deer Creek Reservoir 2561.6 Acres 5 Not Supporting but has Approved TMDL for some parameters Harmful algal blooms Not meeting criteria TMDL Needed Recreation and Aesthetics (Frequent Primary Contact) 2024 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2006 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (4046) Aquatic Wildlife (Cold Water) 1998 Low Upper Provo River UT-L-16020203-003_00 Jordanelle Reservoir 2989.1 Acres 2 No Evidence of Impairment Upper Provo River UT-L-16020203-004_00 Mill Hollow Reservoir 18.3 Acres 5 Not Supporting pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1992 Low Total Phosphorus as P Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1992 Low Upper Provo River UT-L-16020203-002_00 Trial Lake 62.3 Acres 5 Not Supporting pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Upper Provo River UT-L-16020203-006_00 Wall Lake 72.0 Acres 3 Insufficient Data Upper Provo River UT-L-16020203-005_00 Washington Lake 106.7 Acres 2 No Evidence of Impairment Upper Sevier River UT-L-16030002-011_00 Koosharem Reservoir 340.9 Acres 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (30891) Aquatic Wildlife (Cold Water) 1998 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Total Phosphorus as P Not meeting criteria TMDL Approved (30891) Aquatic Wildlife (Cold Water) 1998 Low Upper Sevier River UT-L-16030002-005_00 Lower Box Creek Reservoir 22.2 Acres 5 Not Supporting but has Approved TMDL for some parameters Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (31020) Aquatic Wildlife (Cold Water) 2004 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2010 Low Total Phosphorus as P Not meeting criteria TMDL Approved (31020) Aquatic Wildlife (Cold Water) 1998 Low Upper Sevier River UT-L-16030001-001_00 Navajo Lake 631.0 Acres 5 Not Supporting pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Upper Sevier River UT-L-16030002-004_00 Otter Creek Reservoir 2494.7 Acres 5 Not Supporting but has Approved TMDL for some parameters Harmful algal blooms Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1994 Low Total Phosphorus as P Not meeting criteria TMDL Approved (30890) Aquatic Wildlife (Cold Water) 1998 Low Upper Sevier River UT-L-16030001-006_00 Panguitch Lake 1182.3 Acres 5 Not Supporting but has Approved TMDL for some parameters Harmful algal blooms Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Minimum Dissolved Oxygen Meeting criteria TMDL Approved (11149) Aquatic Wildlife (Cold Water) pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Total Phosphorus as P Not meeting criteria TMDL Approved (11149) Aquatic Wildlife (Cold Water) 2000 Low Upper Sevier River UT-L-16030002-007_00 Pine Lake 85.4 Acres 5 Not Supporting pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Upper Sevier River UT-L-16030001-011_00 Piute Reservoir 2152.3 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment Unit AU Water Quality Cycle First 303(d) Management Unit (AU) ID AU Name Water Size Unit Category Category Description Parameter Parameter Status 303(d) Status Use(s) Listed Priority Total Phosphorus as P Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2006 Low Upper Sevier River UT-L-16030002-002_00 Tropic Reservoir 181.8 Acres 5 Not Supporting pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Utah Lake-Lower Provo River UT-L-16020202-002_00 Big East Lake 26.4 Acres 5 Not Supporting Harmful algal blooms Temperature Minimum Dissolved Oxygen pH Total Phosphorus as P Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed TMDL Needed TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2024 2012 1996 2020 2012 Low Low Low Low Low Utah Lake-Lower Provo River UT-L-16020201-001_00 Mona Reservoir 1561.8 Acres 2 No Evidence of Impairment Utah Lake-Lower Provo River UT-L-16020201-004_02 Provo Bay portion of Utah Lake 3611.5 Acres 5 Not Supporting Eutrophication Harmful algal blooms NA pH Total Ammonia as N Total Phosphorus as P Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed TMDL Needed TMDL Needed TMDL Needed Aquatic Wildlife (Warm Water) Recreation and Aesthetics (Frequent Primary Contact) Aquatic Wildlife (Warm Water) Aquatic Wildlife (Warm Water) Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other) Aquatic Wildlife (Warm Water) 2020 2020 2010 2016 2024 1994 Low Low Low Low Low Low Utah Lake-Lower Provo River UT-L-16020202-001_00 Salem Lake 18.7 Acres 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Frequent Primary Contact) 2016 Low Utah Lake-Lower Provo River UT-L-16020201-004_01 Utah Lake other than Provo Bay 87984.2 Acres 5 Not Supporting E. coli Eutrophication Harmful algal blooms NA Total Dissolved Solids Total Phosphorus as P Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed TMDL Needed TMDL Needed TMDL Needed Recreation and Aesthetics (Frequent Primary Contact) Aquatic Wildlife (Warm Water) Recreation and Aesthetics (Frequent Primary Contact) Aquatic Wildlife (Warm Water) Agricultural Aquatic Wildlife (Warm Water) 2022 2020 2016 2010 2006 1994 Low Low Low Low Low Low Weber River UT-L-16020102-021_00 Causey Reservoir 126.8 Acres 2 No Evidence of Impairment Weber River UT-L-16020102-020_00 East Canyon Reservoir 639.7 Acres 5 Not Supporting but has Approved TMDL for some parameters E. coli Harmful algal blooms Minimum Dissolved Oxygen pH Total Phosphorus as P Not meeting criteria Not meeting criteria Meeting criteria Meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Approved (39157, 400) TMDL Approved (39157) TMDL Approved (39157, 400) Recreation and Aesthetics (Frequent Primary Contact) Recreation and Aesthetics (Frequent Primary Contact) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2024 2024 1988 Low Low Low Weber River UT-L-16020101-001_00 Echo Reservoir 1337.2 Acres 5 Not Supporting but has Approved TMDL for some parameters Harmful algal blooms Minimum Dissolved Oxygen Total Phosphorus as P Not meeting criteria Meeting criteria Not meeting criteria TMDL Needed TMDL Approved (59860) TMDL Approved (59860) Recreation and Aesthetics (Frequent Primary Contact) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2024 1994 Low Low Weber River UT-L-16020101-003_00 Lost Creek Reservoir 369.6 Acres 2 No Evidence of Impairment Weber River UT-L-16020102-014_00 Pineview Reservoir 3009.9 Acres 5 Not Supporting but has Approved TMDL for some parameters E. coli Harmful algal blooms Temperature Minimum Dissolved Oxygen pH Total Phosphorus as P Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed TMDL Approved (4055) TMDL Approved (4055) TMDL Approved (4055) Recreation and Aesthetics (Frequent Primary Contact) Recreation and Aesthetics (Frequent Primary Contact) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2024 2024 1994 1998 2022 1998 Low Low Low Low Low Low Weber River UT-L-16020101-002_00 Rockport Reservoir 1059.8 Acres 5 Not Supporting but has Approved TMDL for some parameters E. coli Harmful algal blooms Minimum Dissolved Oxygen Not meeting criteria Not meeting criteria Meeting criteria TMDL Needed TMDL Needed TMDL Approved (59861) Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) Recreation and Aesthetics (Frequent Primary Contact) Aquatic Wildlife (Cold Water) 2022 2024 Low Low Weber River UT-L-16020101-005_00 Smith and Morehouse Reservoi 207.1 Acres 2 No Evidence of Impairment Weber River UT-L-16020102-004_00 Willard Bay Reservoir 10109.4 Acres 1 Fully Supporting West Desert UT-L-16020304-005_00 Grantsville Reservoir 95.3 Acres 5 Not Supporting Temperature Minimum Dissolved Oxygen pH Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2020 2020 2022 Low Low Low West Desert UT-L-16020304-002_00 Rush Lake 242.5 Acres 2 No Evidence of Impairment West Desert UT-L-16020304-004_00 Settlement Canyon Reservoir 26.0 Acres 2 No Evidence of Impairment West Desert UT-L-16020304-003_00 Stansbury Lake 91.3 Acres 5 Not Supporting Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2016 Low Western Colorado River UT-L-14060009-024_00 Cleveland Reservoir 146.6 Acres 2 No Evidence of Impairment Western Colorado River UT-L-14070003-018_00 Cook Lake 10.4 Acres 2 No Evidence of Impairment Western Colorado River UT-L-14070003-027_00 Donkey Reservoir 23.8 Acres 5 Not Supporting pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Western Colorado River UT-L-14060009-004_00 Duck Fork Reservoir 42.3 Acres 2 No Evidence of Impairment Western Colorado River UT-L-14060009-025_00 Electric Lake 450.7 Acres 2 No Evidence of Impairment Western Colorado River UT-L-14060007-001_00 Fairview Lakes 103.9 Acres 2 No Evidence of Impairment Western Colorado River UT-L-14060009-001_00 Ferron Reservoir 54.1 Acres 2 No Evidence of Impairment Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment Unit AU Water Quality Cycle First 303(d) Management Unit (AU) ID AU Name Water Size Unit Category Category Description Parameter Parameter Status 303(d) Status Use(s) Listed Priority Western Colorado River UT-L-14070003-006_00 Fish Lake 2586.5 Acres 2 No Evidence of Impairment Western Colorado River UT-L-14070003-019_00 Forsyth Reservoir 165.1 Acres 4A Approved TMDL Minimum Dissolved Oxygen Meeting criteria TMDL Approved (4060) Aquatic Wildlife (Cold Water) Total Phosphorus as P Not meeting criteria TMDL Approved (4060) Aquatic Wildlife (Cold Water) 1998 Low Western Colorado River UT-L-14060009-034_00 Huntington Lake North 235.1 Acres 2 No Evidence of Impairment Western Colorado River UT-L-14060009-018_00 Huntington Reservoir 163.0 Acres 2 No Evidence of Impairment Western Colorado River UT-L-14060009-017_00 Joes Valley Reservoir 1052.2 Acres 2 No Evidence of Impairment Western Colorado River UT-L-14070003-010_00 Johnson Valley Reservoir 671.7 Acres 4A Approved TMDL Total Phosphorus as P Not meeting criteria TMDL Approved (4059) Aquatic Wildlife (Cold Water) 1998 Low Western Colorado River UT-L-14070006-001_00 Lake Powell 149885.2 Acres 1 Fully Supporting Western Colorado River UT-L-14070003-044_00 Lower Bowns Reservoir 107.9 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2012 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2010 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2006 Low Total Phosphorus as P Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2012 Low Western Colorado River UT-L-14060007-004_00 Lower Gooseberry Reservoir 64.2 Acres 5 Not Supporting Total Phosphorus as P Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2010 Low Western Colorado River UT-L-14070003-015_00 Mill Meadow Reservoir 160.4 Acres 5 Not Supporting but has Approved TMDL for some parameters Harmful algal blooms Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Total Phosphorus as P Not meeting criteria TMDL Approved (4061) Aquatic Wildlife (Cold Water) 1998 Low Western Colorado River UT-L-14060009-023_00 Miller Flat Reservoir 160.5 Acres 2 No Evidence of Impairment Western Colorado River UT-L-14060009-026_00 Millsite Reservoir 367.1 Acres 2 No Evidence of Impairment Western Colorado River UT-L-14070005-008_00 Posey Lake 12.0 Acres 2 No Evidence of Impairment Western Colorado River UT-L-14060007-005_00 Scofield Reservoir 2670.4 Acres 5 Not Supporting but has Approved TMDL for some parameters Eutrophication Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 High Harmful algal blooms Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (1060) Aquatic Wildlife (Cold Water) 1998 Low pH Not meeting criteria TMDL Approved (1060) Aquatic Wildlife (Cold Water) 2024 Low Total Phosphorus as P Not meeting criteria TMDL Approved (1060) Aquatic Wildlife (Cold Water) 1998 Low Western Colorado River UT-L-14070005-011_00 Wide Hollow Reservoir 155.6 Acres 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2010 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Draft 2024 Integrated Report: Delistings Watershed Management Unit Assessment Unit ID Water Quality Assessment Unit Name Parameter Delisting Reason Delisting Comment Bear River UT-L-16010203-005_00 Hyrum Reservoir Dissolved Oxygen Meeting water quality criteria with new data. Long term improvement in lens width. 8 profiles at 3 sites since 2016 show support for DO and temperature. Bear River UT-L-16010203-005_00 Hyrum Reservoir Temperature Meeting water quality criteria with new data. Long term improvement in lens width. 8 profiles at 3 sites since 2016 show support for DO and temperature. Cedar-Beaver UT-L-16020203-003_00 Jordanelle Reservoir pH Meeting water quality criteria with new data. No pH exceedances since 2016 based on over 20 profiles including the critical time period. Cedar-Beaver UT-L-16030007-011_00 Minersville Reservoir Temperature TMDL Approved by EPA (4A) TMDL Action ID : 808 Weber River UT-L-16020102-020_00 East Canyon Reservoir pH Meeting water quality criteria with new data. Sufficient new data shows that pH exceedances observed in 2016 were isolated and anomolous. No other pH exceedances observed. Weber River UT-L-16020101-002_00 Rockport Reservoir pH Meeting water quality criteria with new data. No pH sample exceedances since 2015. Sufficient new data have been collected to delist. Chapter 3 Assessments Specific to Rivers, Streams and Canals Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Bear River UT16010201-001_00 Bear Lake West 1.2 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Bear River UT16010101-027_00 Bear River East 2.8 Miles 2 No Evidence of Impairment Bear River UT16010204-002_00 Bear River Lower-East 26.2 Miles 5 Not Supporting Minimum Dissolved Oxygen Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other) Agricultural 2024 Low 2012 Low Bear River UT16010204-004_00 Bear River Lower-West 10.4 Miles 3 Insufficient Data Bear River UT16010102-001_00 Bear River North 0.1 Miles 3 Insufficient Data Bear River UT16010101-001_00 Bear River West 6.8 Miles 5 Not Supporting E. coli Temperature Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) Aquatic Wildlife (Cold Water) 2020 Low 2020 Low Bear River UT16010204-003_00 Bear River-1 19.1 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2010 Low Bear River UT16010204-008_01 Bear River-2-1 42.7 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Minimum Dissolved Oxygen Total Dissolved Solids Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed Aquatic Wildlife (Warm Water) Aquatic Wildlife (Warm Water) Agricultural 2008 Low 2024 Low 2024 Low Bear River UT16010204-008_02 Bear River-2-2 13.3 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Warm Water) Agricultural 2008 Low 2020 Low Bear River UT16010202-004_00 Bear River-3 41.4 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Sediment Total Phosphorus as P Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Approved (38238) Recreation and Aesthetics (Infrequent Primary Contact) Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other) Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2020 Low 1998 Low 1998 Low Bear River UT16010101-006_00 Bear River-4 52.6 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (30887) Aquatic Wildlife (Cold Water) 2000 Low Total Phosphorus as P Not meeting criteria TMDL Approved (30887) Aquatic Wildlife (Cold Water) 2000 Low Bear River UT16010101-009_00 Bear River-5 12.2 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Bear River UT16010101-021_00 Bear River-6 20.2 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Bear River UT16010101-007_00 Big Creek 31.0 Miles 5 Not Supporting Assessed HNNC E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2014 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Bear River UT16010101-010_00 Birch Creek - Bear 19.6 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Bear River UT16010203-020_00 Blacksmith Fork-1 11.6 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2016 Low Bear River UT16010203-018_00 Blacksmith Fork-2 56.6 Miles 2 No Evidence of Impairment Bear River UT16010204-001_00 Box Elder Creek-1 0.0 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2024 Low Bear River UT16010204-005_00 Box Elder Creek-2 7.5 Miles 2 No Evidence of Impairment Bear River UT16010202-007_00 Cherry Creek - Bear 5.0 Miles 3 Insufficient Data Bear River UT16010202-006_00 City Creek 8.9 Miles 3 Insufficient Data Bear River UT16010202-013_00 Clarkston Creek 23.9 Miles 1 Fully Supporting Bear River UT16010202-015_00 Clay Slough 3.0 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2012 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other), Agricultural, Recreation and Aesthetics (Infrequent Primary Contact) 2012 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2012 Low Bear River UT16010202-010_00 Cub River 16.5 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Sediment Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 1998 Low Total Phosphorus as P Not meeting criteria TMDL Approved (38238) Aquatic Wildlife (Warm Water) 1998 Low Bear River UT16010203-001_00 Cutler West 2.8 Miles 3 Insufficient Data Bear River UT16010203-015_00 Davenport Creek 37.2 Miles 2 No Evidence of Impairment Bear River UT16010101-017_00 Dry Creek 1.4 Miles 3 Insufficient Data Bear River UT16010101-026_00 East Fork Bear River 53.9 Miles 2 No Evidence of Impairment Bear River UT16010203-014_00 East Fork Little Bear-1 7.7 Miles 1 Fully Supporting Bear River UT16010203-017_00 East Fork Little Bear-2 31.0 Miles 3 Insufficient Data Bear River UT16010101-024_00 Hayden Fork 17.7 Miles 2 No Evidence of Impairment Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First 303(d) Listed Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Bear River UT16010202-008_00 High Creek Lower 3.4 Miles 4A Approved TMDL Total Phosphorus as P TMDL Approved Not meeting criteria (38238) Aquatic Wildlife (Cold Water) 1998 Low Bear River UT16010202-012_00 High Creek Upper 9.5 Miles 1 Fully Supporting Bear River UT16010202-003_00 Hopkins Slough 9.9 Miles 3 Insufficient Data Bear River UT16010201-002_00 Laketown 12.3 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Bear River UT16010203-019_00 Left Hand Fork Blacksmith Fork 25.5 Miles 2 No Evidence of Impairment Bear River UT16010203-012_00 Little Bear River Tributaries 1.0 Miles 2 No Evidence of Impairment Bear River UT16010203-009_00 Little Bear River-1 27.8 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Bear River UT16010203-011_00 Little Bear River-2 8.9 Miles 1 Fully Supporting Bear River UT16010203-007_00 Little Bear-3 15.2 Miles 1 Fully Supporting Bear River UT16010203-010_00 Little Bear-4 2.2 Miles 3 Insufficient Data Bear River UT16010101-003_00 Little Creek - Bear 8.0 Miles 2 No Evidence of Impairment Bear River UT16010203-005_00 Logan River-1 40.0 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Total Phosphorus as P Not meeting criteria TMDL Approved (38238) Aquatic Wildlife (Cold Water) 1998 Low Bear River UT16010203-006_00 Logan River-2 71.8 Miles 5 Not Supporting pH Not meeting criteria TMDL Needed Aquatic Wildlife (Waterfowl, Shorebirds, and Other), Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Bear River UT16010204-006_00 Malad River-1 61.3 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2020 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low pH Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact), Aquatic Wildlife (Non- game Fish and Other) 2024 Low Thallium Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2024 Low Bear River UT16010204-010_01 Malad River-2-1 8.6 Miles 2 No Evidence of Impairment Bear River UT16010204-010_02 Malad River-2-2 3.7 Miles 2 No Evidence of Impairment Bear River UT16010204-011_01 Mantua Reservoir Tributaries-1 1.0 Miles 2 No Evidence of Impairment Bear River UT16010204-011_02 Mantua Reservoir Tributaries-2 1.1 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other), Agricultural, Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Bear River UT16010204-007_01 Middle Bear East-1 4.5 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Bear River UT16010204-007_02 Middle Bear East-2 6.0 Miles 2 No Evidence of Impairment Bear River UT16010101-022_00 Mill Creek 58.7 Miles 2 No Evidence of Impairment Bear River UT16010202-002_00 Newton Creek 2.6 Miles 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Total Phosphorus as P Not meeting criteria TMDL Approved (11147) Aquatic Wildlife (Cold Water) 1996 Low Bear River UT16010201-004_00 North Eden 17.6 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Bear River UT16010101-008_00 North Woodruff 2.4 Miles 3 Insufficient Data Bear River UT16010101-005_00 Otter Creek 25.9 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Bear River UT16010203-016_00 Porcupine Creek 1.5 Miles 2 No Evidence of Impairment Bear River UT16010101-004_00 Sage Creek 11.2 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2014 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2010 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Bear River UT16010101-016_00 Saleratus Creek 29.1 Miles 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2012 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (30885) Aquatic Wildlife (Cold Water) 1998 Low Bear River UT16010204-013_00 Salt Creek-Bothwell 4.8 Miles 3 Insufficient Data Bear River UT16010101-002_00 Six Mile Creek - Bear 19.6 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2016 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Bear River UT16010201-003_00 South Eden 5.9 Miles 2 No Evidence of Impairment Bear River UT16010203-013_00 South Fork Little Bear 21.6 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Bear River UT16010202-009_00 Spring Creek Lewiston 2.3 Miles 4A Approved TMDL Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (38238) Aquatic Wildlife (Warm Water) 1998 Low Total Phosphorus as P Not meeting criteria TMDL Approved (38238, 4012) Aquatic Wildlife (Warm Water) 1998 Low Bear River UT16010203-008_00 Spring Creek-Hyrum 10.9 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Not meeting criteria TMDL Approved (4012) Recreation and Aesthetics (Infrequent Primary Contact) 2002 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2006 Low Total Ammonia as N Not meeting criteria TMDL Approved (4012) Aquatic Wildlife (Waterfowl, Shorebirds, and Other), Aquatic Wildlife (Cold Water) 1998 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2020 Low Bear River UT16010101-025_00 Stillwater Fork 34.9 Miles 5 Not Supporting pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Bear River UT16010202-005_00 Summit Creek Lower 8.0 Miles 1 Fully Supporting Bear River UT16010202-011_00 Summit Creek Upper 10.0 Miles 1 Fully Supporting Bear River UT16010101-018_00 Sutton Creek 35.5 Miles 3 Insufficient Data Bear River UT16010203-002_00 Swift Slough 10.9 Miles 2 No Evidence of Impairment Bear River UT16010202-014_00 The Slough 3.2 Miles 2 No Evidence of Impairment Bear River UT16010101-012_00 Unnamed Creek 0.0 Miles 3 Insufficient Data Bear River UT16010101-023_00 West Fork Bear River 72.1 Miles 2 No Evidence of Impairment Bear River UT16010101-011_00 Woodruff Creek-1 8.2 Miles 2 No Evidence of Impairment Bear River UT16010101-015_00 Woodruff Creek-2 5.8 Miles 2 No Evidence of Impairment Bear River UT16010101-014_00 Woodruff Creek-3 0.0 Miles 3 Insufficient Data Bear River UT16010101-013_00 Woodruff Creek-4 42.1 Miles 3 Insufficient Data Bear River UT16010202-001_00 Worm Creek 0.0 Miles 2 No Evidence of Impairment Bear River UT16010101-028_00 Yellow Creek 16.8 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Bear River UT16010101-019_01 Yellow Creek Tributaries-1 23.3 Miles 2 No Evidence of Impairment Bear River UT16010101-019_02 Yellow Creek Tributaries-2 0.0 Miles 2 No Evidence of Impairment Cedar-Beaver UT16030007-001_00 Beaver River-1 8.0 Miles 3 Insufficient Data Cedar-Beaver UT16030007-002_00 Beaver River-2 65.2 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2016 Low Temperature Not meeting criteria TMDL Approved (96) Aquatic Wildlife (Cold Water) 1998 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (96) Aquatic Wildlife (Cold Water) 2014 Low Cedar-Beaver UT16030007-003_00 Beaver River-3 181.0 Miles 2 No Evidence of Impairment Cedar-Beaver UT16030006-001_00 Coal Creek - C/B 45.2 Miles 1 Fully Supporting Cedar-Beaver UT16030006-009_00 Cottonwood Canyon-Parowan V 6.0 Miles 2 No Evidence of Impairment Cedar-Beaver UT16030006-005_00 Little Creek (Iron Co.) 16.2 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Cedar-Beaver UT16030006-004_00 Parowan Creek 32.9 Miles 2 No Evidence of Impairment Cedar-Beaver UT16030007-004_00 Pine Creek-Tushar 6.3 Miles 3 Insufficient Data Cedar-Beaver UT16030006-002_00 Pinto Creek 31.9 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2016 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Cedar-Beaver UT16030006-007_00 Red Creek (Iron Co.) 7.1 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Cedar-Beaver UT16030006-008_00 Red Creek Lower (Iron Co.) 0.5 Miles 3 Insufficient Data Cedar-Beaver UT16030006-006_00 Shoal Creek 6.2 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Cedar-Beaver UT16030006-003_00 Summit Creek-Iron 15.2 Miles 2 No Evidence of Impairment Jordan River UT16020201-002_01 American Fork River-2 29.2 Miles 2 No Evidence of Impairment Jordan River UT16020204-028_00 Barneys Canyon Creek 2.4 Miles 3 Insufficient Data Jordan River UT16020204-030_00 Bells Canyon 4.4 Miles 3 Insufficient Data Jordan River UT16020204-019_00 Big Cottonwood Creek-1 10.0 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First 303(d) Listed Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC E. coli Temperature TMDL Approved (R8- Recreation and Aesthetics (Infrequent Not meeting criteria UT-2023-01) Primary Contact) Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 High 2006 Low Jordan River UT16020204-020_00 Big Cottonwood Creek-2 44.5 Miles 5 Not Supporting Cadmium Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2022 Low Jordan River UT16020204-006_02 Big Willow Creek 6.00E-04 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2008 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2006 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2024 Low Jordan River UT16020204-023_00 Bingham Creek 4.4 Miles 5 Not Supporting E. coli Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) Agricultural 2024 Low 2014 Low Jordan River UT16020204-024_02 Butterfield Creek 4.7 Miles 5 Not Supporting E. coli Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) Agricultural 2024 Low 2014 Low Jordan River UT16020204-009_00 City Creek-1 4.2 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Jordan River UT16020204-010_00 City Creek-2 6.3 Miles 1 Fully Supporting Jordan River UT16020204-027_00 Coon Creek 4.1 Miles 3 Insufficient Data Jordan River UT16020204-006_03 Dry Creek 0.0 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Temperature Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Waterfowl, Shorebirds, and Other) Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2008 Low 2006 Low Jordan River UT16020201-015_00 Dry Creek-Alpine 11.3 Miles 5 Not Supporting pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2014 Low Jordan River UT16020204-012_00 Emigration Creek 3.7 Miles 4A Approved TMDL E. coli Not meeting criteria TMDL Approved (42669) Recreation and Aesthetics (Infrequent Primary Contact) 2008 Low Jordan River UT16020204-033_00 Emigration Creek Lower 1.1 Miles 4A Approved TMDL E. coli Not meeting criteria TMDL Approved (R8- UT-2023-01) Recreation and Aesthetics (Infrequent Primary Contact) 2014 High Jordan River UT16020204-001_01 Jordan River-1 9.1 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2008 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (54300) Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2002 High Jordan River UT16020204-002_00 Jordan River-2 4.4 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2008 Low TMDL Approved (R8- Recreation and Aesthetics (Infrequent E. coli Not meeting criteria Minimum Dissolved Oxygen Not meeting criteria UT-2023-01) TMDL Approved (54321) Primary Contact) 2006 Low Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2002 High Not Supporting but has Approved TMDL Jordan River UT16020204-003_00 Jordan River-3 4.4 Miles 5 for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2008 Low TMDL Approved (R8- Recreation and Aesthetics (Infrequent E. coli Not meeting criteria UT-2023-01) Primary Contact) 2006 High Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (54322) Aquatic Wildlife (Warm Water) 2008 High Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2024 Low Total Phosphorus as P Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2008 Low Jordan River UT16020204-004_00 Jordan River-4 5.7 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2010 Low TMDL Approved (R8- Recreation and Aesthetics (Infrequent E. coli Not meeting criteria UT-2023-01) Primary Contact) 2014 High Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2008 Low Jordan River UT16020204-005_00 Jordan River-5 4.6 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Not meeting criteria TMDL Approved (R8- UT-2023-01) Recreation and Aesthetics (Infrequent Primary Contact) 2006 High Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2006 Low Jordan River UT16020204-006_01 Jordan River-6 12.6 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2008 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2006 Low Jordan River UT16020204-007_00 Jordan River-7 3.8 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2008 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2020 Low Jordan River UT16020201-008_00 Jordan River-8 9.9 Miles 5 Not Supporting Arsenic Not meeting criteria TMDL Needed Domestic Source 2014 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2006 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Jordan River UT16020204-036_00 Lee Creek 5.2 Miles 1 Fully Supporting Jordan River UT16020204-021_00 Little Cottonwood Creek-1 9.7 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2008 Low Cadmium Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low TMDL Approved (R8- Recreation and Aesthetics (Infrequent E. coli Not meeting criteria UT-2023-01) Primary Contact) 2014 High Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2006 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2006 Low Jordan River UT16020204-022_00 Little Cottonwood Creek-2 30.0 Miles 5 Not Supporting but has Approved TMDL for some parameters Cadmium Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2014 Low Zinc Not meeting criteria TMDL Approved (4014) Aquatic Wildlife (Cold Water) 1998 Low Jordan River UT16020204-031_00 Little Willow Creek 2.8 Miles 3 Insufficient Data Jordan River UT16020201-002_02 Mary Ellen Gulch 3.6 Miles 5 Not Supporting Cadmium Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Zinc Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Jordan River UT16020204-024_01 Midas Creek 1.5 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Not meeting criteria TMDL Approved (R8- UT-2023-01) Recreation and Aesthetics (Infrequent Primary Contact) 2014 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2014 Low Jordan River UT16020204-026_00 Mill Creek1-SLCity 1.1 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2014 Low TMDL Approved (R8- Recreation and Aesthetics (Infrequent E. coli Not meeting criteria UT-2023-01) Primary Contact) 2014 High Jordan River UT16020204-017_00 Mill Creek2-SLCity 7.5 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2010 Low TMDL Approved (R8- Recreation and Aesthetics (Infrequent E. coli Not meeting criteria UT-2023-01) Primary Contact) 2002 High Jordan River UT16020204-018_00 Mill Creek3-SLCity 19.1 Miles 1 Fully Supporting Jordan River UT16020204-014_00 Mountain Dell Creek-1 0.8 Miles 1 Fully Supporting Jordan River UT16020204-015_00 Mountain Dell Creek-2 7.8 Miles 2 No Evidence of Impairment Jordan River UT16020204-016_00 North Canyon 0.0 Miles 1 Fully Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2008 Low Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2014 Low Minimum Dissolved Oxygen Meeting criteria TMDL Approved (54300) Aquatic Wildlife (Waterfowl, Shorebirds, and Other) Jordan River UT16020204-025_00 Parleys Canyon Creek-1 13.6 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low TMDL Approved (R8- Recreation and Aesthetics (Infrequent E. coli Not meeting criteria UT-2023-01) Primary Contact), Domestic Source 2010 High Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Jordan River UT16020204-013_00 Parleys Canyon Creek-2 15.7 Miles 5 Not Supporting but has Approved TMDL for some parameters Cadmium Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low TMDL Approved (R8- Recreation and Aesthetics (Infrequent E. coli Not meeting criteria UT-2023-01) Primary Contact), Domestic Source 2022 Low Not Supporting but has Approved TMDL Jor dan River UT16020204-035_00 Red Butte Creek Lower 2.3 Miles 5 for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low TMDL Approved (R8- Recreation and Aesthetics (Infrequent E. coli Not meeting criteria UT-2023-01) Primary Contact) 2022 High Jordan River UT16020204-011_00 Red Butte Creek Upper 5.6 Miles 3 Insufficient Data Jordan River UT16020204-029_00 Rose Creek 7.0 Miles 4A Approved TMDL E. coli Not meeting criteria TMDL Approved (R8- UT-2023-01) Recreation and Aesthetics (Infrequent Primary Contact) 2014 High Jordan River UT16020204-032_00 Surplus Canal 11.5 Miles 3 Insufficient Data Lower Colorado River UT15010008-007_00 Ash Creek-1 27.2 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Lower Colorado River UT15010008-008_00 Ash Creek-2 8.1 Miles 3 Insufficient Data Lower Colorado River UT15010008-009_00 Ash Creek-3 44.5 Miles 2 No Evidence of Impairment Lower Colorado River UT15010010-002_00 Beaver Dam Wash 24.4 Miles 2 No Evidence of Impairment Lower Colorado River UT15010003-001_00 Cottonwood Canyon 6.0 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2014 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First 303(d) Listed Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2014 Low Lower Colorado River UT15010008-017_00 Deep Creek 66.1 Miles 2 No Evidence of Impairment Lower Colorado River UT15010008-018_00 East Fork Virgin-1 38.5 Miles 5 Not Supporting Assessed HNNC Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2024 Low Lower Colorado River UT15010008-019_00 East Fork Virgin-2 25.8 Miles 1 Fully Supporting Lower Colorado River UT15010008-020_00 East Fork Virgin-3 35.9 Miles 3 Insufficient Data Lower Colorado River UT15010009-001_00 Fort Pearce Wash 0.0 Miles 5 Not Supporting Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2012 Low Lower Colorado River UT15010003-004_00 Johnson Wash-1 22.2 Miles 5 Not Supporting Boron Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Agricultural Agricultural 2014 Low 2008 Low Lower Colorado River UT15010003-005_00 Johnson Wash-2 27.2 Miles 5 Not Supporting Temperature Minimum Dissolved Oxygen pH Total Dissolved Solids Zinc Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) Agricultural Aquatic Wildlife (Cold Water) 2014 Low 2014 Low 2022 Low 2014 Low 2014 Low Lower Colorado River UT15010003-002_01 Kanab Creek-1-1 6.7 Miles 5 Not Supporting Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2008 Low Lower Colorado River UT15010003-002_02 Kanab Creek-1-2 11.4 Miles 5 Not Supporting Minimum Dissolved Oxygen Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Non-game Fish and Other) Agricultural 2024 Low 2008 Low Lower Colorado River UT15010003-003_00 Kanab Creek-2 6.2 Miles 5 Not Supporting Boron Selenium Total Dissolved Solids Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed Agricultural Agricultural, Aquatic Wildlife (Non-game Fish and Other) Agricultural 2014 Low 2016 Low 2014 Low Lower Colorado River UT15010003-006_00 Kanab Creek-3 1.2 Miles 3 Insufficient Data Lower Colorado River UT15010008-016_00 Kolob Creek 15.6 Miles 3 Insufficient Data Lower Colorado River UT15010008-010_00 La Verkin Creek 48.0 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2016 Low Lower Colorado River UT15010008-006_00 Leeds Creek 10.4 Miles 2 No Evidence of Impairment Lower Colorado River UT15010008-014_00 North Creek-Virgin 25.4 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Temperature Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Non-game Fish and Other) Aquatic Wildlife (Non-game Fish and Other) 2016 Low 2024 Low Lower Colorado River UT15010008-015_00 North Fork Virgin River-1 47.2 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Not meeting criteria TMDL Approved (R8- UT-2018-01) Recreation and Aesthetics (Frequent Primary Contact) 2024 Low E. coli Meeting criteria TMDL Approved (R8- UT-2018-01) Domestic Source 2024 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2010 Low Lower Colorado River UT15010008-013_00 North Fork Virgin River-2 37.7 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Not meeting criteria TMDL Approved (R8- UT-2018-01) Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) 2010 High Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Lower Colorado River UT15010008-005_00 Quail Creek 1.0 Miles 3 Insufficient Data Lower Colorado River UT15010008-001_00 Santa Clara-1 23.8 Miles 5 Not Supporting but has Approved TMDL for some parameters Boron Not meeting criteria TMDL Needed Agricultural 2008 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2008 Low Total Dissolved Solids Not meeting criteria TMDL Approved (12104) Agricultural 1998 Low Lower Colorado River UT15010008-002_00 Santa Clara-2 27.0 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Lower Colorado River UT15010008-003_00 Santa Clara-3 38.1 Miles 5 Not Supporting Threatened TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Lower Colorado River UT15010009-002_00 Short Creek 5.3 Miles 3 Insufficient Data Lower Colorado River UT15010010-001_00 Virgin River-1 11.9 Miles 5 Not Supporting Boron Not meeting criteria TMDL Needed Agricultural 2008 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2006 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2014 Low Lower Colorado River UT15010008-004_00 Virgin River-2 34.6 Miles 5 Not Supporting Boron Not meeting criteria TMDL Needed Agricultural 2008 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2022 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2014 Low Lower Colorado River UT15010008-011_00 Virgin River-3 4.3 Miles 1 Fully Supporting Lower Colorado River UT15010008-012_00 Virgin River-4 20.5 Miles 3 Insufficient Data Lower Sevier River UT16030003-007_00 Beaver Creek-1 Sevier 17.2 Miles 1 Fully Supporting Lower Sevier River UT16030003-020_00 Beaver Creek2-Piute 54.7 Miles 3 Insufficient Data Lower Sevier River UT16030005-018_00 Chalk Creek-1 0.0 Miles 3 Insufficient Data Lower Sevier River UT16030005-019_00 Chalk Creek2-Fillmore 35.1 Miles 5 Not Supporting pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Lower Sevier River UT16030005-002_00 Cherry Creek 26.4 Miles 3 Insufficient Data Lower Sevier River UT16030005-020_00 Chicken Creek-1 13.4 Miles 2 No Evidence of Impairment Lower Sevier River UT16030005-022_00 Chicken Creek-2 25.1 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 1998 Low Lower Sevier River UT16030005-011_00 Chicken Creek-3 13.4 Miles 3 Insufficient Data Lower Sevier River UT16030003-018_00 Clear Creek-I70 120.0 Miles 5 Not Supporting Aluminum Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Agricultural 2014 Low 2022 Low Lower Sevier River UT16030005-021_00 Corn Creek 61.7 Miles 1 Fully Supporting Lower Sevier River UT16030004-013_00 Cottonwood Creek-SP 10.4 Miles 1 Fully Supporting Lower Sevier River UT16030004-007_02 Ephraim Creek 4.8 Miles 2 No Evidence of Impairment Lower Sevier River UT16030005-006_00 Fishlake National Forest-I15 12.3 Miles 3 Insufficient Data Lower Sevier River UT16030005-005_00 Fool Creek-1 0.0 Miles 3 Insufficient Data Lower Sevier River UT16030005-014_00 Goose Creek-2 0.3 Miles 3 Insufficient Data Lower Sevier River UT16030005-012_00 Ivie Creek 16.6 Miles 2 No Evidence of Impairment Lower Sevier River UT16030003-005_00 Lost Creek-1 5.9 Miles 5 Not Supporting Boron Temperature Total Dissolved Solids Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed Agricultural Aquatic Wildlife (Non-game Fish and Other) Agricultural 2016 Low 2022 Low 2012 Low Lower Sevier River UT16030003-008_00 Lost Creek2-Salina 8.5 Miles 3 Insufficient Data Lower Sevier River UT16030003-010_00 Lost Creek3-Salina 33.3 Miles 5 Not Supporting E. coli Temperature Minimum Dissolved Oxygen Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2020 Low 2022 Low 2022 Low Lower Sevier River UT16030003-021_00 Manning Creek 19.6 Miles 5 Not Supporting Assessed HNNC Minimum Dissolved Oxygen pH Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2014 Low 2022 Low Lower Sevier River UT16030005-023_00 Meadow Creek 6.3 Miles 2 No Evidence of Impairment Lower Sevier River UT16030003-013_00 Monroe Creek 78.6 Miles 1 Fully Supporting Lower Sevier River UT16030004-012_00 Oak Creek Upper 7.1 Miles 1 Fully Supporting Lower Sevier River UT16030004-006_00 Oak Creek-1 16.0 Miles 3 Insufficient Data Lower Sevier River UT16030005-004_00 Oak Creek-1 0.0 Miles 3 Insufficient Data Lower Sevier River UT16030004-010_00 Oak Creek-2 23.4 Miles 1 Fully Supporting Lower Sevier River UT16030003-027_00 Peterson Creek 8.1 Miles 5 Not Supporting Temperature Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Non-game Fish and Other) Agricultural 2022 Low 2016 Low Lower Sevier River UT16030005-015_00 Pioneer Creek-1 0.4 Miles 3 Insufficient Data Lower Sevier River UT16030005-016_00 Pioneer Creek-2 3.8 Miles 3 Insufficient Data Lower Sevier River UT16030004-008_00 Pleasant Creek 58.0 Miles 1 Fully Supporting Lower Sevier River UT16030005-024_00 Round Valley Creek 0.0 Miles 3 Insufficient Data Lower Sevier River UT16030003-003_00 Salina Creek-1 4.6 Miles 4A Approved TMDL Total Dissolved Solids Not meeting criteria TMDL Approved (11125) Agricultural 1998 Low Lower Sevier River UT16030003-006_00 Salina Creek-2 158.4 Miles 5 Not Supporting E. coli Temperature Minimum Dissolved Oxygen pH Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low 2022 Low 2022 Low 2020 Low Lower Sevier River UT16030004-001_00 San Pitch-1 19.0 Miles 4A Approved TMDL Total Dissolved Solids Not meeting criteria TMDL Approved (11150) Agricultural 2014 Low Lower Sevier River UT16030004-005_01 San Pitch-3-1 68.5 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Minimum Dissolved Oxygen pH Total Ammonia as N Total Dissolved Solids Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed TMDL Needed TMDL Approved (11151) Recreation and Aesthetics (Infrequent Primary Contact) Aquatic Wildlife (Waterfowl, Shorebirds, and Other), Aquatic Wildlife (Non-game Fish and Other) Aquatic Wildlife (Waterfowl, Shorebirds, and Other), Agricultural, Recreation and Aesthetics (Infrequent Primary Contact), Aquatic Wildlife (Non-game Fish and Other) Aquatic Wildlife (Waterfowl, Shorebirds, and Other), Aquatic Wildlife (Non-game Fish and Other) Agricultural 2016 Low 2020 Low 2024 Low 2016 Low 1998 Low Lower Sevier River UT16030004-005_02 San Pitch-3-2 0.0 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2016 Low Total Ammonia as N Not meeting criteria TMDL Needed Aquatic Wildlife (Waterfowl, Shorebirds, and Other), Aquatic Wildlife (Non-game Fish and Other) 2016 Low Total Dissolved Solids Not meeting criteria TMDL Approved (11151) Agricultural 1998 Low Lower Sevier River UT16030004-011_00 San Pitch-4 14.1 Miles 5 Not Supporting Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2014 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First 303(d) Listed Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Lower Sevier River UT16030004-009_00 San Pitch-5 71.1 Miles Not Supporting but has Approved TMDL 5 for some parameters E. coli Temperature pH Recreation and Aesthetics (Infrequent Not meeting criteria TMDL Needed Primary Contact) Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) Agricultural, Aquatic Wildlife (Cold Water), TMDL Approved Recreation and Aesthetics (Infrequent Not meeting criteria (11151) Primary Contact) 2016 Low 2020 Low 2022 Low Lower Sevier River UT16030003-016_00 Sevier River-10 1.5 Miles 3 Insufficient Data Lower Sevier River UT16030003-009_00 Sevier River-11 0.0 Miles 3 Insufficient Data Lower Sevier River UT16030003-011_00 Sevier River-12 13.6 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Lower Sevier River UT16030003-025_00 Sevier River-13 1.7 Miles 3 Insufficient Data Lower Sevier River UT16030003-014_00 Sevier River-14 12.4 Miles 2 No Evidence of Impairment Lower Sevier River UT16030003-024_00 Sevier River-15 14.9 Miles 2 No Evidence of Impairment Lower Sevier River UT16030003-004_01 Sevier River-16-1 3.4 Miles 3 Insufficient Data Lower Sevier River UT16030003-004_02 Sevier River-16-2 0.2 Miles 3 Insufficient Data Lower Sevier River UT16030003-004_03 Sevier River-16-3 0.0 Miles 3 Insufficient Data Lower Sevier River UT16030003-012_00 Sevier River-17 28.8 Miles 4A Approved TMDL Sediment Total Dissolved Solids Total Phosphorus as P Not meeting criteria Not meeting criteria Not meeting criteria TMDL Approved (11122) TMDL Approved (11122, 11150) TMDL Approved (11122) Aquatic Wildlife (Warm Water) Agricultural Aquatic Wildlife (Warm Water) 2000 Low 2000 Low 2000 Low Lower Sevier River UT16030003-023_00 Sevier River-18 29.9 Miles 3 Insufficient Data Lower Sevier River UT16030003-001_00 Sevier River-19 0.1 Miles 3 Insufficient Data Lower Sevier River UT16030005-025_00 Sevier River-20 36.1 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2008 Low Lower Sevier River UT16030005-007_00 Sevier River-21 21.1 Miles 3 Insufficient Data Lower Sevier River UT16030005-026_00 Sevier River-22 39.0 Miles 4A Approved TMDL Sediment Total Phosphorus as P Not meeting criteria Not meeting criteria TMDL Approved (11124) TMDL Approved (11124) Aquatic Wildlife (Warm Water) Aquatic Wildlife (Warm Water) 1998 Low 1998 Low Lower Sevier River UT16030005-017_00 Sevier River-23 0.0 Miles 3 Insufficient Data Lower Sevier River UT16030005-027_00 Sevier River-24 17.2 Miles 5 Not Supporting but has Approved TMDL for some parameters pH Sediment Total Phosphorus as P Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Approved (11124) TMDL Approved (11124) Aquatic Wildlife (Warm Water), Agricultural, Recreation and Aesthetics (Infrequent Primary Contact) Aquatic Wildlife (Warm Water) Aquatic Wildlife (Warm Water) 2022 Low 1998 Low 1998 Low Lower Sevier River UT16030005-028_00 Sevier River-25 19.8 Miles 1 Fully Supporting Lower Sevier River UT16030005-029_00 Sevier River-26 0.0 Miles 3 Insufficient Data Lower Sevier River UT16030005-008_00 Sevier River-27 0.6 Miles 1 Fully Supporting Lower Sevier River UT16030003-022_00 Sevier River-5 9.3 Miles 3 Insufficient Data Lower Sevier River UT16030003-017_00 Sevier River-6 31.1 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2006 Low Lower Sevier River UT16030003-026_00 Sevier River-7 0.0 Miles 5 Not Supporting Temperature pH Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2014 Low 2014 Low Lower Sevier River UT16030003-015_00 Sevier River-8 29.4 Miles 1 Fully Supporting Lower Sevier River UT16030003-019_00 Sevier River-9 11.5 Miles 3 Insufficient Data Lower Sevier River UT16030004-003_00 Six Mile Creek - Sevier 40.2 Miles 5 Not Supporting Temperature Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Agricultural 2012 Low 2022 Low Lower Sevier River UT16030004-004_00 South Creek 33.5 Miles 2 No Evidence of Impairment Lower Sevier River UT16030005-003_00 Tanner Creek 15.1 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Severely Habitat-Limited) 2024 Low Lower Sevier River UT16030004-002_00 Twelve Mile Creek 71.6 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Lower Sevier River UT16030004-007_01 Upper Willow Creek 15.3 Miles 2 No Evidence of Impairment Lower Sevier River UT16030003-002_00 Willow Creek - Axtell 15.8 Miles 2 No Evidence of Impairment Southeast Colorado River UT14030001-004_00 Bitter Creek 3.8 Miles 3 Insufficient Data Southeast Colorado River UT14080201-001_00 Butler Wash 3.8 Miles 3 Insufficient Data Southeast Colorado River UT14030005-009_00 Castle Creek-1 12.9 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments E. coli Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Warm Water) Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) 2008 Low 2020 High Southeast Colorado River UT14030005-012_00 Castle Creek-2 6.7 Miles 1 Fully Supporting Southeast Colorado River UT14070001-003_00 Colorado River-2 15.3 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2024 Low Southeast Colorado River UT14030005-003_00 Colorado River-3 62.3 Miles 1 Fully Supporting Selenium Meeting criteria TMDL Approved (60105) Aquatic Wildlife (Warm Water) Southeast Colorado River UT14030005-004_00 Colorado River-4 35.9 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Frequent Primary Contact) 2020 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First 303(d) Listed Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Temperature Selenium Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) TMDL Approved Not meeting criteria (60104) Aquatic Wildlife (Warm Water) 2024 Low 2006 Low Southeast Colorado River UT14030001-005_00 Colorado River-5 33.3 Miles 4A Approved TMDL Selenium Not meeting criteria TMDL Approved (60103) Aquatic Wildlife (Warm Water) 2004 Low Southeast Colorado River UT14010005-001_00 Colorado River-6 3.8 Miles 4A Approved TMDL Selenium Not meeting criteria TMDL Approved (60100) Aquatic Wildlife (Warm Water) 2004 Low Southeast Colorado River UT14080201-011_00 Comb Wash 7.2 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2020 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2014 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2014 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2014 Low Southeast Colorado River UT14030001-001_00 Cottonwood Wash 22.7 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2014 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2020 Low Southeast Colorado River UT14080201-002_00 Cottonwood Wash-1 0.0 Miles 2 No Evidence of Impairment Southeast Colorado River UT14080201-006_00 Cottonwood Wash-2 5.7 Miles 5 Not Supporting but has Approved TMDL for some parameters Arsenic Not meeting criteria TMDL Needed Domestic Source 2022 Low Gross Alpha Not meeting criteria TMDL Approved (4013) Domestic Source 1998 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2022 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2012 Low Radium Not meeting criteria TMDL Needed Domestic Source 1998 Low Southeast Colorado River UT14080201-007_00 Cottonwood Wash-3 8.9 Miles 5 Not Supporting but has Approved TMDL for some parameters Gross Alpha Not meeting criteria TMDL Approved (4013) Agricultural, Domestic Source 2010 Low Radium Not meeting criteria TMDL Needed Agricultural, Domestic Source 2010 Low Southeast Colorado River UT14030005-017_00 Courthouse Wash 0.0 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2020 Low Southeast Colorado River UT14030005-018_00 Courthouse Wash 1.1 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2024 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2022 Low Southeast Colorado River UT14030004-001_00 Dolores River 61.6 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2020 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2014 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2024 Low Southeast Colorado River UT14080205-002_00 Grand Gulch 0.0 Miles 3 Insufficient Data Southeast Colorado River UT14030005-008_00 Grandstaff Canyon 8.6 Miles 1 Fully Supporting Southeast Colorado River UT14030004-002_00 Granite Creek - CRSE 10.8 Miles 3 Insufficient Data Southeast Colorado River UT14030005-014_00 Indian Creek-1 8.6 Miles 2 No Evidence of Impairment Southeast Colorado River UT14030005-002_00 Indian Creek-2 17.6 Miles 1 Fully Supporting Southeast Colorado River UT14080201-004_00 Johnson Creek 4.2 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2010 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Southeast Colorado River UT14030005-001_00 Kane Spring Wash 22.2 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2014 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2014 Low Southeast Colorado River UT14030002-001_01 La Sal Creek-1 23.9 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Southeast Colorado River UT14030002-001_02 La Sal Creek-2 0.0 Miles 3 Insufficient Data Southeast Colorado River UT14070006-007_01 Lake Powell Tributaries-4-1 1.4 Miles 3 Insufficient Data Southeast Colorado River UT14070006-007_02 Lake Powell Tributaries-4-2 0.0 Miles 3 Insufficient Data Southeast Colorado River UT14030001-002_00 Little Dolores River 7.2 Miles 3 Insufficient Data Southeast Colorado River UT14080202-001_00 McElmo Creek 18.8 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2024 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2024 Low Southeast Colorado River UT14030005-006_01 Mill Creek-2-Moab 11.2 Miles 2 No Evidence of Impairment Not Supporting but has Approved TMDL Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source, Recreation and Aesthetics (Frequent Southeast Colorado River UT14030005-005_00 Mill Creek1-Moab 28.5 Miles 5 for some parameters E. coli Not meeting criteria TMDL Needed Primary Contact) 2016 High Temperature Not meeting criteria TMDL Approved (4047) Aquatic Wildlife (Cold Water) 1998 Low Southeast Colorado River UT14080203-005_01 Montezuma Creek-1-1 0.0 Miles 2 No Evidence of Impairment Southeast Colorado River UT14080203-003_00 Montezuma Creek-2 5.6 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Aquatic Wildlife (Cold Water) 2024 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First 303(d) Listed Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Southeast Colorado River UT14080203-007_00 Montezuma Creek-3 10.1 Miles 5 Not Supporting Selenium Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Southeast Colorado River UT14030001-006_00 Nash Wash 6.4 Miles 2 No Evidence of Impairment Southeast Colorado River UT14030005-015_00 North Cottonwood Creek 28.6 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2014 Low Southeast Colorado River UT14080203-008_00 North Creek 4.5 Miles 3 Insufficient Data Southeast Colorado River UT14030005-010_00 Onion Creek Lower 8.7 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2024 Low Temperature Meeting criteria TMDL Approved (4008) Aquatic Wildlife (Warm Water) Total Dissolved Solids Not meeting criteria TMDL Approved (4008) Agricultural 2016 Low Southeast Colorado River UT14030005-013_00 Onion Creek Upper 2.8 Miles 1 Fully Supporting Not Supporting but has Approved TMDL Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source, Recreation and Aesthetics (Frequent Southeast Colorado River UT14030005-011_00 Pack Creek 8.9 Miles 5 for some parameters E. coli Not meeting criteria TMDL Needed Primary Contact) 2016 High Temperature Not meeting criteria TMDL Approved (4047) Aquatic Wildlife (Cold Water) 2006 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2006 Low Southeast Colorado River UT14030005-006_02 Pack Creek-2 15.6 Miles 1 Fully Supporting Southeast Colorado River UT14030005-019_00 Professor Creek 0.0 Miles 5 Not Supporting Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2012 Low Southeast Colorado River UT14080201-005_00 Recapture Creek-1 1.6 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2020 Low Southeast Colorado River UT14080201-003_00 Recapture Creek-2 3.7 Miles 3 Insufficient Data Southeast Colorado River UT14030004-003_00 Roc Creek 23.7 Miles 3 Insufficient Data Southeast Colorado River UT14030005-016_00 Salt Creek-Canyonlands 0.0 Miles 3 Insufficient Data Southeast Colorado River UT14030005-007_00 Salt Wash 22.1 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2024 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2016 Low Southeast Colorado River UT14080205-001_00 San Juan River-1 62.5 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2024 Low Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2024 Low Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2022 Low E. coli Not meeting criteria TMDL Needed Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) 2020 Low Iron Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2022 Low Lead Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Domestic Source 2022 Low Thallium Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Domestic Source 2022 Low Southeast Colorado River UT14080205-003_00 San Juan River-1 Triburaries 8.4 Miles 5 Not Supporting Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2012 Low Southeast Colorado River UT14080201-009_00 San Juan River-2 28.5 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2020 Low Cadmium Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2016 Low E. coli Not meeting criteria TMDL Needed Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) 2020 Low Iron Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2016 Low Lead Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2016 Low Thallium Not meeting criteria TMDL Needed Domestic Source 2022 Low Southeast Colorado River UT14080201-010_00 San Juan River-3 30.1 Miles 3 Insufficient Data Southeast Colorado River UT14080203-004_00 South Creek 0.0 Miles 3 Insufficient Data Southeast Colorado River UT14080203-006_00 Spring Creek 5.9 Miles 3 Insufficient Data Southeast Colorado River UT14010005-002_00 Unknown tribs 0.0 Miles 3 Insufficient Data Southeast Colorado River UT14080203-001_00 Verdure Creek-1 5.3 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Aquatic Wildlife (Cold Water) 2024 Low Southeast Colorado River UT14080203-002_00 Verdure Creek-2 11.0 Miles 3 Insufficient Data Southeast Colorado River UT14030001-003_00 Westwater Creek 18.4 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2012 Low Southeast Colorado River UT14080201-008_00 Westwater Creek 5.8 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2012 Low Selenium Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2012 Low Southeast Colorado River UT14030001-003_00 Westwater Creek 18.4 Miles 5 Not Supporting Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2012 Low Southeast Colorado River UT14070001-004_00 White Canyon 0.0 Miles 3 Insufficient Data Uinta Basin UT14060003-005_00 Antelope Creek 34.1 Miles 5 Not Supporting Arsenic Not meeting criteria TMDL Needed Domestic Source 2014 Low Boron Not meeting criteria TMDL Needed Agricultural 2008 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 1998 Low Uinta Basin UT14040107-002_00 Archie Creek 4.7 Miles 2 No Evidence of Impairment Uinta Basin UT14060010-001_00 Ashley Creek Lower 7.8 Miles 5 Not Supporting Selenium Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Agricultural 1992 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 1992 Low Uinta Basin UT14060010-007_00 Ashley Creek Upper 70.6 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2022 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Uinta Basin UT14060004-005_00 Avintaquin Creek 51.8 Miles 5 Not Supporting Arsenic Not meeting criteria TMDL Needed Domestic Source 2008 Low Uinta Basin UT14060008-006_00 Barrier Creek 1.0 Miles 3 Insufficient Data Uinta Basin UT14040106-027_00 Beaver Creek 1.5 Miles 2 No Evidence of Impairment Uinta Basin UT14060010-006_00 Big Brush Creek 38.3 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Uinta Basin UT14040106-006_00 Birch Creek-tribs 14.8 Miles 3 Insufficient Data Uinta Basin UT14040106-009_00 Birch Spring Draw 23.8 Miles 5 Not Supporting Cadmium Selenium Total Dissolved Solids Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed Aquatic Wildlife (Non-game Fish and Other) Agricultural, Aquatic Wildlife (Non-game Fish and Other) Agricultural 2024 Low 2012 Low 2012 Low Uinta Basin UT14050007-002_00 Bitter Creek Lower 0.0 Miles 5 Not Supporting Boron Temperature Minimum Dissolved Oxygen Selenium Total Dissolved Solids Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed TMDL Needed TMDL Needed Agricultural Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Agricultural 2014 Low 2014 Low 2020 Low 2014 Low 2014 Low Uinta Basin UT14050007-005_00 Bitter Creek Upper 27.5 Miles 5 Not Supporting Temperature Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Agricultural 2014 Low 2014 Low Uinta Basin UT14040107-001_00 Blacks Fork 180.3 Miles 5 Not Supporting Aluminum Zinc Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2014 Low 2024 Low Uinta Basin UT14060010-003_00 Brush Creek 25.7 Miles 5 Not Supporting E. coli Selenium Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) Aquatic Wildlife (Warm Water) 2014 Low 2004 Low Uinta Basin UT14040106-005_00 Burnt Fork Creek 44.0 Miles 2 No Evidence of Impairment Uinta Basin UT14040106-014_00 Cart Creek 17.7 Miles 5 Not Supporting Aluminum Minimum Dissolved Oxygen Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2014 Low 2020 Low Uinta Basin UT14040106-010_00 Carter Creek 111.7 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Uinta Basin UT14060004-009_00 Currant Creek Lower 71.0 Miles 1 Fully Supporting Uinta Basin UT14060004-015_00 Currant Creek Upper 74.1 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Uinta Basin UT14040106-001_00 Dahlgreen Creek 0.0 Miles 2 No Evidence of Impairment Uinta Basin UT14040106-016_00 Davenport Creek 5.8 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Uinta Basin UT14060003-012_00 Deep Creek - Uinta 27.8 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Uinta Basin UT14060010-013_00 Diamond Gulch 32.6 Miles 5 Not Supporting E. coli Minimum Dissolved Oxygen Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) Aquatic Wildlife (Cold Water) 2020 Low 2022 Low Uinta Basin UT14060010-008_00 Dry Fork Creek Lower 6.7 Miles 2 No Evidence of Impairment Uinta Basin UT14060010-009_00 Dry Fork Creek Upper 48.3 Miles 2 No Evidence of Impairment Uinta Basin UT14060003-009_00 Dry Gulch Creek 99.2 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Approved (4058) Recreation and Aesthetics (Infrequent Primary Contact) Agricultural 2014 Low 1998 Low Uinta Basin UT14060003-001_00 Duchesne River-1 17.2 Miles 5 Not Supporting but has Approved TMDL for some parameters Boron E. coli Total Dissolved Solids Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Approved (33615) Agricultural Recreation and Aesthetics (Infrequent Primary Contact) Agricultural 2024 Low 2014 Low 1998 Low Uinta Basin UT14060003-002_00 Duchesne River-2 30.9 Miles 5 Not Supporting but has Approved TMDL for some parameters Boron E. coli Total Dissolved Solids Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Approved (33616) Agricultural Recreation and Aesthetics (Infrequent Primary Contact) Agricultural 2016 Low 2014 Low 2016 Low Uinta Basin UT14060003-006_00 Duchesne River-3 43.4 Miles 3 Insufficient Data Uinta Basin UT14060003-017_00 Duchesne River-4 78.3 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Uinta Basin UT14040106-011_00 Eagle Creek 10.0 Miles 1 Fully Supporting Uinta Basin UT14040107-005_00 East Fork Smiths Fork 61.5 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Uinta Basin UT14050007-003_00 Evacuation Creek 0.4 Miles 5 Not Supporting Boron Temperature Minimum Dissolved Oxygen Total Dissolved Solids Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed TMDL Needed Agricultural Aquatic Wildlife (Warm Water) Aquatic Wildlife (Warm Water) Agricultural 2014 Low 2014 Low 2024 Low 2008 Low Uinta Basin UT14040106-012_01 Flaming Gorge Tributaries-1 0.0 Miles 3 Insufficient Data Uinta Basin UT14040106-012_02 Flaming Gorge Tributaries-2 10.7 Miles 3 Insufficient Data Uinta Basin UT14040106-012_03 Flaming Gorge Tributaries-3 0.0 Miles 3 Insufficient Data Uinta Basin UT14040106-012_04 Flaming Gorge Tributaries-4 3.0 Miles 2 No Evidence of Impairment Uinta Basin UT14060005-007_00 Florence Creek 33.6 Miles 3 Insufficient Data Uinta Basin UT14060008-004_00 Floy Creek 27.2 Miles 2 No Evidence of Impairment Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Uinta Basin UT14040107-004_00 Gilbert Creek 7.6 Miles 2 No Evidence of Impairment Uinta Basin UT14040106-015_00 Gorge Creek 8.4 Miles 2 No Evidence of Impairment Uinta Basin UT14040106-017_00 Goslin Creek 4.9 Miles 1 Fully Supporting Uinta Basin UT14040106-019_00 Green River-1 29.6 Miles 1 Fully Supporting Uinta Basin UT14040106-008_01 Green River-1 Tribs-1 14.9 Miles 1 Fully Supporting Uinta Basin UT14040106-008_02 Green River-1 Tribs-2 7.2 Miles 1 Fully Supporting Uinta Basin UT14040106-008_03 Green River-1 Tribs-3 5.0 Miles 2 No Evidence of Impairment Uinta Basin UT14040106-008_04 Green River-1 Tribs-4 0.0 Miles 1 Fully Supporting Uinta Basin UT14060010-010_00 Green River-2 99.7 Miles 5 Not Supporting E. coli pH Selenium Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed Recreation and Aesthetics (Frequent Primary Contact) Aquatic Wildlife (Warm Water), Agricultural, Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) Aquatic Wildlife (Warm Water) 2022 Low 2022 Low 2014 Low Uinta Basin UT14060010-011_01 Green River-2 Tribs-1 1.2 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) 2014 Low Uinta Basin UT14060010-011_02 Green River-2 Tribs-2 0.5 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) 2014 Low Uinta Basin UT14060010-011_03 Green River-2 Tribs-3 4.7 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) 2014 Low Uinta Basin UT14060010-011_04 Green River-2 Tribs-4 7.5 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) 2014 Low Uinta Basin UT14060005-009_00 Green River-3 111.7 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments pH Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Warm Water) Aquatic Wildlife (Warm Water), Agricultural, Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) 2024 Low 2020 Low Uinta Basin UT14060005-001_01 Green River-3 Tribs-1 2.6 Miles 3 Insufficient Data Uinta Basin UT14060005-001_02 Green River-3 Tribs-2 0.0 Miles 3 Insufficient Data Uinta Basin UT14060005-001_03 Green River-3 Tribs-3 0.1 Miles 3 Insufficient Data Uinta Basin UT14060005-001_04 Green River-3 Tribs-4 35.5 Miles 3 Insufficient Data Uinta Basin UT14060005-001_05 Green River-3 Tribs-5 23.4 Miles 3 Insufficient Data Uinta Basin UT14060005-001_06 Green River-3 Tribs-6 25.1 Miles 3 Insufficient Data Uinta Basin UT14060005-001_07 Green River-3 Tribs-7 0.0 Miles 3 Insufficient Data Uinta Basin UT14060005-001_08 Green River-3 Tribs-8 53.4 Miles 3 Insufficient Data Uinta Basin UT14060008-001_00 Green River-4 42.4 Miles 1 Fully Supporting Uinta Basin UT14060008-002_00 Green River-5 98.7 Miles 2 No Evidence of Impairment Uinta Basin UT14060008-003_00 Green River-5 Tributaries 7.9 Miles 2 No Evidence of Impairment Uinta Basin UT14040106-002_00 Henrys Fork River 60.0 Miles 2 No Evidence of Impairment Uinta Basin UT14060006-003_00 Hill Creek 105.3 Miles 3 Insufficient Data Uinta Basin UT14060008-005_00 Horse Canyon-Canyonlands 0.0 Miles 3 Insufficient Data Uinta Basin UT14060004-002_00 Indian Canyon Creek 48.2 Miles 5 Not Supporting Arsenic Boron Total Dissolved Solids Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed Domestic Source Agricultural Agricultural 2008 Low 2008 Low 1998 Low Uinta Basin UT14040106-020_00 Jackson Creek 11.4 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Uinta Basin UT14060010-012_00 Jones Hole Creek 6.0 Miles 1 Fully Supporting Uinta Basin UT14060003-008_00 Lake Fork-1 33.2 Miles 5 Not Supporting but has Approved TMDL for some parameters Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water), Aquatic Wildlife (Severely Habitat-Limited) 2020 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2000 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Total Dissolved Solids Not meeting criteria TMDL Approved (33617) Agricultural 2004 Low Uinta Basin UT14060003-015_00 Lake Fork-2 34.9 Miles 1 Fully Supporting Uinta Basin UT14060003-022_00 Lake Fork-3 29.9 Miles 3 Insufficient Data Uinta Basin UT14060010-004_00 Little Brush Creek Lower 8.5 Miles 2 No Evidence of Impairment Uinta Basin UT14060010-005_00 Little Brush Creek Upper 36.2 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2014 Low Uinta Basin UT14060010-002_00 Middle Ashley Creek 18.2 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2014 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Selenium Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2008 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2008 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Uinta Basin UT14040106-004_00 Middle Fork Beaver Creek 33.0 Miles 1 Fully Supporting Uinta Basin Uinta Basin UT14060003-021_00 UT14060005-003_00 Moon Lake Tributaries Ninemile 149.5 Miles 156.7 Miles 5 5 Not Supporting Not Supporting but has Approved TMDL for some parameters Minimum Dissolved Oxygen Temperature Not meeting criteria Not meeting criteria TMDL Needed TMDL Approved (68462) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2014 Low 1998 High Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Uinta Basin UT14060003-019_00 North Fork Duchesne 64.6 Miles 1 Fully Supporting Uinta Basin UT14040106-025_00 O-Wi-Yu-Kuts Creek 2.2 Miles 3 Insufficient Data Uinta Basin UT14060005-002_00 Pariette Draw Creek 59.1 Miles 5 Not Supporting but has Approved TMDL for some parameters Boron Not meeting criteria TMDL Approved (39159) Agricultural 1998 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2024 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2020 Low Selenium Not meeting criteria TMDL Approved (39159) Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 1998 Low Total Dissolved Solids Not meeting criteria TMDL Approved (39159) Agricultural 1998 Low Uinta Basin UT14060003-014_00 Pole Creek 35.8 Miles 1 Fully Supporting Uinta Basin UT14040106-021_00 Pot Creek 25.1 Miles 5 Not Supporting Iron Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Uinta Basin UT14040106-023_00 Pot Creek Lower 0.4 Miles 3 Insufficient Data Uinta Basin UT14060005-006_00 Range Creek Lower 9.3 Miles 2 No Evidence of Impairment Uinta Basin UT14060005-005_00 Range Creek Middle 26.4 Miles 2 No Evidence of Impairment Uinta Basin UT14060005-004_00 Range Creek Upper 6.4 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Uinta Basin UT14040106-018_00 Red Creek 15.7 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2020 Low Uinta Basin UT14060004-006_00 Red Creek Lower 6.3 Miles 2 No Evidence of Impairment Uinta Basin UT14060004-007_00 Red Creek Middle 20.1 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Uinta Basin UT14060004-008_00 Red Creek Upper 20.7 Miles 3 Insufficient Data Uinta Basin UT14060005-008_00 Rock Creek 28.1 Miles 3 Insufficient Data Uinta Basin UT14060003-016_00 Rock Creek Lower 29.9 Miles 3 Insufficient Data Uinta Basin UT14060003-020_00 Rock Creek Upper 104.4 Miles 1 Fully Supporting Uinta Basin UT14040106-022_00 Sears Creek 7.9 Miles 2 No Evidence of Impairment Uinta Basin UT14040106-007_00 Sheep Creek 122.1 Miles 1 Fully Supporting Uinta Basin UT14040106-013_00 Spring Creek 5.1 Miles 3 Insufficient Data Uinta Basin UT14060004-003_01 Starvation Tributaries-1 0.0 Miles 2 No Evidence of Impairment Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2020 Low Uinta Basin UT14060004-004_00 Stawberry River-2 22.4 Miles 5 Not Supporting Arsenic Not meeting criteria TMDL Needed Domestic Source 2020 Low Uinta Basin UT14060004-014_00 Strawberry River Upper 62.7 Miles 1 Fully Supporting Uinta Basin UT14060004-001_00 Strawberry River-1 6.5 Miles 1 Fully Supporting Uinta Basin UT14060004-010_00 Strawberry River-3 23.2 Miles 1 Fully Supporting Uinta Basin UT14060004-013_00 Strawberry-4 120.0 Miles 5 Not Supporting Assessed HNNC Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2014 Low Uinta Basin UT14050007-004_00 Sweetwater Creek 4.2 Miles 2 No Evidence of Impairment Uinta Basin UT14060008-007_00 Ten Mile Canyon - Grand 3.5 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2014 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2014 Low Uinta Basin UT14060004-011_00 Timber Canyon Creek 17.1 Miles 5 Not Supporting Arsenic Not meeting criteria TMDL Needed Domestic Source 2014 Low Uinta Basin UT14040106-026_00 Tolivers Creek 6.6 Miles 2 No Evidence of Impairment Uinta Basin UT14060003-003_00 Uinta River-1 6.0 Miles 4A Approved TMDL Total Dissolved Solids Not meeting criteria TMDL Approved (4056) Agricultural 2016 Low Uinta Basin UT14060003-004_00 Uinta River-2 7.2 Miles 4A Approved TMDL Total Dissolved Solids Not meeting criteria TMDL Approved (4056) Agricultural 1998 Low Uinta Basin UT14060003-010_00 Uinta River-3 76.7 Miles 3 Insufficient Data Uinta Basin UT14060003-024_00 Uinta River-4 95.7 Miles 5 Not Supporting Zinc Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Uinta Basin UT14040106-003_00 West Fork Beaver Creek 24.2 Miles 1 Fully Supporting Uinta Basin UT14060003-018_00 West Fork Duchesne 89.8 Miles 1 Fully Supporting Uinta Basin UT14040107-003_00 West Fork Smiths Fork 22.7 Miles 2 No Evidence of Impairment Uinta Basin UT14040108-001_00 West Muddy Creek 7.2 Miles 3 Insufficient Data Uinta Basin UT14050007-001_00 White River 70.8 Miles 1 Fully Supporting Uinta Basin UT14060003-011_00 Whiterocks River Lower 30.7 Miles 2 No Evidence of Impairment Uinta Basin UT14060003-013_00 Whiterocks River Upper 92.3 Miles 2 No Evidence of Impairment Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First 303(d) Listed Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Uinta Basin UT14060006-001_00 Willow Creek 74.6 Miles 5 Not Supporting Boron Temperature Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) Not meeting criteria TMDL Needed Agricultural 2014 Low 2022 Low 2020 Low Uinta Basin UT14040106-024_00 Willow Creek - Daggett 16.5 Miles 1 Fully Supporting Uinta Basin UT14060004-012_00 Willow Creek - Wasatch 15.9 Miles 2 No Evidence of Impairment Uinta Basin UT14060006-002_00 Willow Creek Upper 161.5 Miles 2 No Evidence of Impairment Uinta Basin UT14060003-023_00 Yellowstone Upper 126.2 Miles 2 No Evidence of Impairment Uinta Basin UT14060003-007_00 Zimmerman Wash 0.8 Miles 5 Not Supporting Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2020 Low Upper Provo River UT16020203-022_00 Bridal Veil Falls 0.0 Miles 3 Insufficient Data Upper Provo River UT16020203-011_00 Daniels Creek-1 10.7 Miles 2 No Evidence of Impairment Upper Provo River UT16020203-012_00 Daniels Creek-2 11.6 Miles 2 No Evidence of Impairment Upper Provo River UT16020203-026_00 Heber Valley 46.9 Miles 5 Not Supporting E. coli pH Not meeting criteria Not meeting criteria Recreation and Aesthetics (Infrequent TMDL Needed Primary Contact), Domestic Source Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent TMDL Needed Primary Contact), Domestic Source 2020 Low 2022 Low Upper Provo River UT16020203-019_00 Lake Creek-2 22.9 Miles 1 Fully Supporting Upper Provo River UT16020203-017_00 Little South Fork Provo 30.3 Miles 2 No Evidence of Impairment Upper Provo River UT16020203-020_00 Lost Creek and tributaries from 0.0 Miles 3 Insufficient Data Upper Provo River UT16020203-009_00 Main Creek-1 7.4 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments E. coli Temperature Minimum Dissolved Oxygen pH Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) Recreation and Aesthetics (Infrequent TMDL Needed Primary Contact), Domestic Source TMDL Needed Aquatic Wildlife (Cold Water) TMDL Needed Aquatic Wildlife (Cold Water) Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent TMDL Needed Primary Contact), Domestic Source 2016 Low 2010 Low 2020 Low 2022 Low 2024 Low Upper Provo River UT16020203-010_00 Main Creek-2 34.4 Miles 5 Not Supporting E. coli Not meeting criteria Recreation and Aesthetics (Infrequent TMDL Needed Primary Contact), Domestic Source 2016 Low Upper Provo River UT16020203-016_00 McHenry Creek 0.9 Miles 1 Fully Supporting Upper Provo River UT16020203-008_00 North Fork Provo River 8.0 Miles 2 No Evidence of Impairment Upper Provo River UT16020203-025_00 Provo Canyon 0.0 Miles 3 Insufficient Data Upper Provo River UT16020203-013_00 Provo Deer Creek 20.5 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Upper Provo River UT16020203-023_00 Provo Lower Tributaries 0.0 Miles 3 Insufficient Data Upper Provo River UT16020203-002_00 Provo River-2 4.0 Miles 5 Not Supporting Assessed HNNC Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Upper Provo River UT16020203-003_00 Provo River-3 6.3 Miles 5 Not Supporting Assessed HNNC Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Upper Provo River UT16020203-004_00 Provo River-4 14.3 Miles 1 Fully Supporting Upper Provo River UT16020203-005_00 Provo River-5 13.1 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Upper Provo River UT16020203-006_01 Provo River-6-1 26.4 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Upper Provo River UT16020203-006_02 Provo River-6-2 39.7 Miles 5 Not Supporting Aluminum Zinc Not meeting criteria Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low 2014 Low Upper Provo River UT16020203-006_03 Provo River-6-3 40.9 Miles 5 Not Supporting Aluminum Copper pH Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) TMDL Needed Aquatic Wildlife (Cold Water) Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent TMDL Needed Primary Contact), Domestic Source 2014 Low 2020 Low 2020 Low Upper Provo River UT16020203-028_01 Provo Tributaries-Heber-1 4.6 Miles 3 Insufficient Data Upper Provo River UT16020203-028_02 Provo Tributaries-Heber-2 10.9 Miles 3 Insufficient Data Upper Provo River UT16020203-024_00 Rock Canyon 3.4 Miles 3 Insufficient Data Upper Provo River UT16020203-014_00 Snake Creek-1 4.9 Miles 5 Not Supporting Arsenic Chromium Not meeting criteria Not meeting criteria TMDL Needed Domestic Source TMDL Needed Aquatic Wildlife (Cold Water) 2006 High 2022 Low Upper Provo River UT16020203-015_00 Snake Creek-2 17.3 Miles 5 Not Supporting Arsenic E. coli Not meeting criteria Not meeting criteria TMDL Needed Domestic Source Recreation and Aesthetics (Infrequent TMDL Needed Primary Contact), Domestic Source 2024 Low 2020 Low Upper Provo River UT16020203-018_00 South Fork Provo 30.6 Miles 1 Fully Supporting Upper Provo River UT16020203-007_00 South Fork Provo River 10.7 Miles 1 Fully Supporting Upper Provo River UT16020203-027_00 Spring Creek-Heber 11.7 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli pH Not meeting criteria Not meeting criteria TMDL Approved (R8- Recreation and Aesthetics (Infrequent UT-2022-01) Primary Contact), Domestic Source Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent TMDL Needed Primary Contact), Domestic Source 2016 High 2024 Low Upper Provo River UT16020203-021_00 Upper Falls Drainage 0.4 Miles 3 Insufficient Data Upper Sevier River UT16030002-008_00 Antimony Creek 28.1 Miles 1 Fully Supporting Upper Sevier River UT16030001-011_00 Asay Creek 47.4 Miles 1 Fully Supporting Upper Sevier River UT16030001-004_00 Bear Creek 8.2 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water) 2014 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC E. coli Recreation and Aesthetics (Infrequent Not meeting criteria TMDL Needed Primary Contact) Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Not meeting criteria TMDL Needed Primary Contact) 2020 Low Temperature 2014 Low pH 2022 Low Upper Sevier River UT16030002-007_00 Deer Creek 18.7 Miles 1 Fully Supporting Upper Sevier River UT16030001-010_00 Duck Creek 4.4 Miles 1 Fully Supporting Upper Sevier River UT16030002-005_00 East Fork Sevier River-4 27.3 Miles 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2006 Low Total Phosphorus as P Not meeting criteria TMDL Approved (30892) Aquatic Wildlife (Cold Water) 2000 Low Upper Sevier River UT16030002-010_00 East Fork Sevier-1 41.8 Miles 2 No Evidence of Impairment Upper Sevier River UT16030002-009_00 East Fork Sevier-2 137.3 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Upper Sevier River UT16030002-006_00 East Fork Sevier-3 24.5 Miles 1 Fully Supporting Upper Sevier River UT16030001-009_00 Mammoth Creek Lower 26.0 Miles 4A Approved TMDL Total Phosphorus as P Not meeting criteria TMDL Approved (11129) Aquatic Wildlife (Cold Water) 2004 Low Upper Sevier River UT16030001-015_00 Mammoth Creek Upper 28.3 Miles 3 Insufficient Data Upper Sevier River UT16030002-002_00 Otter Creek-1 96.4 Miles 5 Not Supporting Assessed HNNC Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Upper Sevier River UT16030002-004_00 Otter Creek-2 23.1 Miles 4A Approved TMDL Minimum Dissolved Oxygen Not meeting criteria TMDL Approved (900) Aquatic Wildlife (Cold Water) 2012 Low Sediment Not meeting criteria TMDL Approved (900) Aquatic Wildlife (Cold Water) 1998 Low Total Phosphorus as P Not meeting criteria TMDL Approved (900) Aquatic Wildlife (Cold Water) 1998 Low Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 1998 Low Upper Sevier River UT16030002-003_00 Otter Creek-3 29.8 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Sediment Not meeting criteria TMDL Approved (900) Aquatic Wildlife (Cold Water) 1998 Low Total Phosphorus as P Not meeting criteria TMDL Approved (900) Aquatic Wildlife (Cold Water) 1998 Low Upper Sevier River UT16030002-001_00 Otter Creek-4 23.6 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2016 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Upper Sevier River UT16030001-008_00 Panguitch Creek-1 25.3 Miles 1 Fully Supporting Upper Sevier River UT16030001-006_00 Panguitch Creek-2 39.2 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Upper Sevier River UT16030001-013_00 Piute 3.5 Miles 3 Insufficient Data Upper Sevier River UT16030001-001_00 Piute West 11.6 Miles 3 Insufficient Data Upper Sevier River UT16030001-012_00 Sevier River-1 34.6 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Upper Sevier River UT16030001-007_00 Sevier River-2 52.7 Miles 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Sediment Not meeting criteria TMDL Approved (11127) Aquatic Wildlife (Cold Water) 2002 Low Total Phosphorus as P Not meeting criteria TMDL Approved (11127) Aquatic Wildlife (Cold Water) 2002 Low Upper Sevier River UT16030001-005_00 Sevier River-3 22.1 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Sediment Not meeting criteria TMDL Approved (11126) Aquatic Wildlife (Cold Water) 1998 Low Total Phosphorus as P Not meeting criteria TMDL Approved (30892, 11126) Aquatic Wildlife (Cold Water) 1998 Low Upper Sevier River UT16030001-002_00 Sevier River-4 17.9 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Upper Sevier River UT16030001-014_00 Threemile Creek 25.1 Miles 5 Not Supporting Assessed HNNC Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Threatened TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Utah Lake-Lower Provo River UT16020201-016_00 American Fork 0.1 Miles 1 Fully Supporting Utah Lake-Lower Provo River UT16020201-001_00 American Fork River-1 7.1 Miles 1 Fully Supporting Utah Lake-Lower Provo River UT16020202-027_00 Beer Creek 16.4 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments E. coli Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Non-game Fish and Other) Recreation and Aesthetics (Infrequent Primary Contact) 2014 Low 2020 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2024 Low Utah Lake-Lower Provo River UT16020202-030_00 Benjamin Slough 6.2 Miles 5 Not Supporting Total Ammonia as N Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2016 Low Utah Lake-Lower Provo River UT16020202-024_00 Bennie Creek 4.8 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020202-019_00 Clear Creek-Tucker 13.6 Miles 2 No Evidence of Impairment Utah Lake-Lower Provo River UT16020202-011_00 Cottonwood Creek 11.4 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Utah Lake-Lower Provo River UT16020201-003_00 Currant Creek 4.2 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2002 Low Utah Lake-Lower Provo River UT16020201-017_00 Currant Creek-Goshen 19.4 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2022 Low Utah Lake-Lower Provo River UT16020201-014_00 Currant Creek-Juab Valley 21.3 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Utah Lake-Lower Provo River UT16020202-017_00 Dairy Fork 5.9 Miles 2 No Evidence of Impairment Utah Lake-Lower Provo River UT16020202-006_00 Diamond Fork-1 26.6 Miles 1 Fully Supporting Utah Lake-Lower Provo River UT16020202-007_00 Diamond Fork-2 4.3 Miles 1 Fully Supporting Utah Lake-Lower Provo River UT16020202-008_00 Diamond Fork-3 27.2 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Utah Lake-Lower Provo River UT16020202-035_00 Dry Creek-1 3.2 Miles 5 Not Supporting E. coli Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) Agricultural 2020 Low 2024 Low Utah Lake-Lower Provo River UT16020202-036_00 Dry Creek-2 8.7 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020202-003_00 Hobble Creek-1 10.5 Miles 1 Fully Supporting Utah Lake-Lower Provo River UT16020202-004_00 Hobble Creek-2 25.4 Miles 2 No Evidence of Impairment Utah Lake-Lower Provo River UT16020202-005_00 Hobble Creek-3 30.7 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Utah Lake-Lower Provo River UT16020201-006_00 Hop Creek 16.3 Miles 1 Fully Supporting Utah Lake-Lower Provo River UT16020202-021_00 Indian Creek 3.1 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020201-013_00 Ironton Canal Lower 0.1 Miles 2 No Evidence of Impairment Utah Lake-Lower Provo River UT16020202-016_00 Lake Fork 29.6 Miles 2 No Evidence of Impairment Utah Lake-Lower Provo River UT16020201-011_00 Lindon Hollow 0.8 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020202-018_00 Mill Fork 10.5 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020201-012_00 Mill Race Creek-1 0.5 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments E. coli Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Warm Water) Recreation and Aesthetics (Infrequent Primary Contact) 2016 Low 2020 Low Utah Lake-Lower Provo River UT16020202-031_00 Moark 0.0 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020202-025_00 Nebo Creek 40.2 Miles 2 No Evidence of Impairment Utah Lake-Lower Provo River UT16020202-028_00 Peteetneet Creek 22.0 Miles 2 No Evidence of Impairment Utah Lake-Lower Provo River UT16020201-010_00 Powell Slough 0.0 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2014 Low Utah Lake-Lower Provo River UT16020203-001_00 Provo River-1 11.1 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Temperature Minimum Dissolved Oxygen Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2008 Low 2024 Low 2022 Low Utah Lake-Lower Provo River UT16020201-004_00 Salt Creek-1 2.3 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020201-005_00 Salt Creek-2 22.6 Miles 5 Not Supporting pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2014 Low Utah Lake-Lower Provo River UT16020202-014_00 Sheep Creek 5.5 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020202-009_00 Sixth Water Creek 20.4 Miles 5 Not Supporting pH Selenium Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) Aquatic Wildlife (Cold Water) 2022 Low 2024 Low Utah Lake-Lower Provo River UT16020202-012_00 Soldier Creek-1 21.0 Miles 5 Not Supporting but has Approved TMDL for some parameters Temperature Sediment Total Phosphorus as P Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Approved (31023) TMDL Approved (31023) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2014 Low 1998 Low 1998 Low Utah Lake-Lower Provo River UT16020202-013_00 Soldier Creek-2 6.9 Miles 2 No Evidence of Impairment Utah Lake-Lower Provo River UT16020202-033_00 Soldier Creek-3 0.0 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020202-034_00 Soldier Creek-4 2.2 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020202-039_00 Soldier Creek-5 0.0 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020202-001_00 Spanish Fork River-1 16.6 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Utah Lake-Lower Provo River UT16020202-002_00 Spanish Fork River-2 6.6 Miles 2 No Evidence of Impairment Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First 303(d) Listed Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Utah Lake-Lower Provo River UT16020201-009_00 Spring Creek-Lehi 4.9 Miles 5 Not Supporting E. coli Temperature Minimum Dissolved Oxygen Recreation and Aesthetics (Infrequent Not meeting criteria TMDL Needed Primary Contact) Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low 2022 Low 2020 Low Utah Lake-Lower Provo River UT16020202-026_00 Spring Creek-Payson 13.3 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020202-042_00 Spring Creek-Springville 3.0 Miles 5 Not Supporting Total Ammonia as N Meeting criteria TMDL Needed Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2024 Low Total Ammonia as N Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2024 Low Utah Lake-Lower Provo River UT16020202-020_00 Starvation Creek 19.0 Miles 2 No Evidence of Impairment Utah Lake-Lower Provo River UT16020201-007_00 Summit Creek-Santaquin 8.0 Miles 2 No Evidence of Impairment Utah Lake-Lower Provo River UT16020202-010_00 Third Water Creek 24.7 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Utah Lake-Lower Provo River UT16020202-022_00 Thistle Creek-1 21.2 Miles 4A Approved TMDL Sediment Not meeting criteria TMDL Approved (33611) Aquatic Wildlife (Cold Water) 2008 Low Utah Lake-Lower Provo River UT16020202-023_00 Thistle Creek-2 20.6 Miles 2 No Evidence of Impairment Utah Lake-Lower Provo River UT16020202-037_00 Thistle Creek-3 10.5 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020202-038_00 Thistle Creek-4 1.2 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020202-032_00 Thistle Creek-5 0.0 Miles 3 Insufficient Data Utah Lake-Lower Provo River UT16020202-015_00 Tie Fork 14.9 Miles 2 No Evidence of Impairment Weber River UT16020102-053_00 Baer Creek-1 1.2 Miles 5 Not Supporting Copper E. coli Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Non-game Fish and Other) Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low 2020 Low Weber River UT16020102-051_00 Baer Creek-2 2.3 Miles 3 Insufficient Data Weber River UT16020102-036_00 Baer Creek-3 2.8 Miles 5 Not Supporting Aluminum Copper Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2024 Low 2022 Low Weber River UT16020102-043_00 Barnard Creek 1.9 Miles 5 Not Supporting Copper E. coli Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Recreation and Aesthetics (Infrequent Primary Contact) 2014 Low 2016 Low Weber River UT16020102-047_00 Barton Creek 3.6 Miles 5 Not Supporting Aluminum pH Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low 2024 Low Weber River UT16020101-029_00 Beaver Creek-1 15.9 Miles 1 Fully Supporting Weber River UT16020102-011_00 Beaver Creek-Weber 20.0 Miles 1 Fully Supporting Weber River UT16020101-030_00 Beaver Creek2-Kamas 22.5 Miles 5 Not Supporting Aluminum Copper Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2020 Low 2024 Low Weber River UT16020102-014_00 Burch Creek-1 3.2 Miles 1 Fully Supporting Weber River UT16020102-004_00 Burch Creek-2 4.1 Miles 2 No Evidence of Impairment Weber River UT16020101-008_00 Carruth Creek 7.9 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2020 Low Weber River UT16020102-044_02 Centerville Canyon 5.4 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Weber River UT16020101-012_00 Chalk Creek-2 5.6 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2020 Low Weber River UT16020101-016_00 Chalk Creek-4 54.8 Miles 5 Not Supporting but has Approved TMDL for some parameters Minimum Dissolved Oxygen Sediment Total Phosphorus as P Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Approved (239) TMDL Approved (239) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2020 Low 1998 Low 1998 Low Weber River UT16020101-010_00 Chalk Creek1-Coalville 8.2 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2024 Low Weber River UT16020101-014_00 Chalk Creek3-Coalville 17.2 Miles 4A Approved TMDL Sediment Total Phosphorus as P Not meeting criteria Not meeting criteria Not meeting criteria TMDL Approved (239) TMDL Approved (239) TMDL Needed Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 1998 Low 1998 Low 1998 Low Weber River UT16020102-056_00 Corbett Creek 1.8 Miles 3 Insufficient Data Weber River UT16020102-018_00 Cottonwood Creek 6.5 Miles 3 Insufficient Data Weber River UT16020102-041_00 Davis Creek 2.3 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Weber River UT16020102-024_00 East Canyon Creek-1 25.5 Miles 1 Fully Supporting Weber River UT16020102-026_01 East Canyon Creek-2-1 33.4 Miles 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Total Phosphorus as P Not meeting criteria TMDL Approved (399) Aquatic Wildlife (Cold Water) 1992 Low Weber River UT16020102-026_04 East Canyon Creek-2-2 3.1 Miles 2 No Evidence of Impairment Weber River UT16020102-025_00 East Canyon Creek-3 5.2 Miles 3 Insufficient Data Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Weber River UT16020101-015_00 East Fork Chalk Creek 35.2 Miles 1 Fully Supporting Weber River UT16020101-007_00 Echo Creek 44.4 Miles 5 Not Supporting but has Approved TMDL for some parameters Sediment Not meeting criteria TMDL Approved (30893) Aquatic Wildlife (Cold Water) 1998 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2014 Low Weber River UT16020102-039_00 Farmington Creek-1 0.2 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2020 Low Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2014 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2014 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2022 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Agricultural, Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low Weber River UT16020102-038_00 Farmington Creek-2 20.1 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2024 Low Weber River UT16020101-022_00 Fort Creek 11.1 Miles 1 Fully Supporting Weber River UT16020102-003_00 Four Mile Creek 2.7 Miles 1 Fully Supporting Weber River UT16020101-002_00 Francis Creek 8.1 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2024 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Weber River UT16020101-009_00 Grass Creek 10.2 Miles 3 Insufficient Data Weber River UT16020102-023_00 Hardscrabble Creek 27.8 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2012 Low Weber River UT16020102-035_00 Holmes Creek-1 10.0 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2014 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2014 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Agricultural, Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Weber River UT16020102-034_00 Holmes Creek-2 5.9 Miles 2 No Evidence of Impairment Weber River UT16020101-013_00 Huff Creek 20.5 Miles 5 Not Supporting but has Approved TMDL for some parameters Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Sediment Not meeting criteria TMDL Approved (239) Aquatic Wildlife (Cold Water) 1998 Low Total Phosphorus as P Not meeting criteria TMDL Approved (239) Aquatic Wildlife (Cold Water) 1998 Low Weber River UT16020102-031_00 Kays Creek 7.7 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2016 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2014 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Agricultural, Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Weber River UT16020102-027_00 Kimball Creek 13.7 Miles 5 Not Supporting Arsenic Not meeting criteria TMDL Needed Domestic Source 2014 Low Weber River UT16020101-001_00 Lost Creek1-Croydon 26.1 Miles 1 Fully Supporting Weber River UT16020101-003_00 Lost Creek2-Croydon 57.0 Miles 3 Insufficient Data Weber River UT16020101-005_00 Main Canyon 12.7 Miles 2 No Evidence of Impairment Weber River UT16020102-032_02 Middle Fork Kays Creek 0.0 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Weber River UT16020102-009_00 Middle Fork Ogden River 30.6 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Weber River UT16020102-050_00 Mill Creek1-Davis 0.2 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2014 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Agricultural, Recreation and Aesthetics (Infrequent Primary Contact) 2024 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2014 Low Weber River UT16020102-049_00 Mill Creek2-Davis 6.6 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Weber River UT16020102-026_02 Murnin Creek 7.4 Miles 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2014 Low Total Phosphorus as P Not meeting criteria TMDL Approved (399) Aquatic Wildlife (Cold Water) 1992 Low Weber River UT16020102-030_00 North Fork Kays Creek 2.2 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Weber River UT16020102-006_00 North Fork Ogden River 50.0 Miles 5 Not Supporting Assessed HNNC Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Weber River UT16020102-005_00 Ogden River-1 10.0 Miles 1 Fully Supporting Weber River UT16020102-044_01 Parrish Creek 3.9 Miles 1 Fully Supporting Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Weber River UT16020102-042_00 Ricks Creek 3.4 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Weber River UT16020102-052_00 Rudd Creek 1.1 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2022 Low Weber River UT16020101-031_00 Sawmill Creek 2.8 Miles 1 Fully Supporting Weber River UT16020102-037_00 Shepard Creek 0.0 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Weber River UT16020101-020_01 Silver Creek-1 13.2 Miles 5 Not Supporting but has Approved TMDL for some parameters Arsenic Not meeting criteria TMDL Needed Domestic Source 2006 Low Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Cadmium Not meeting criteria TMDL Approved (11152) Agricultural, Aquatic Wildlife (Cold Water), Domestic Source 1998 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2020 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2010 Low Zinc Not meeting criteria TMDL Approved (11152) Aquatic Wildlife (Cold Water) 1998 Low Not meeting criteria TMDL Needed Domestic Source 2014 Low Weber River UT16020101-020_02 Silver Creek-2 26.2 Miles 5 Not Supporting but has Approved TMDL for some parameters Arsenic Not meeting criteria TMDL Needed Domestic Source 2006 Low Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Cadmium Not meeting criteria TMDL Approved (11152) Agricultural, Aquatic Wildlife (Cold Water), Domestic Source 1998 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2020 Low Lead Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water), Domestic Source 2024 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Zinc Not meeting criteria TMDL Approved (11152) Aquatic Wildlife (Cold Water) 1998 Low Not meeting criteria TMDL Needed Domestic Source 2014 Low Weber River UT16020101-026_00 Smith Morehouse River-1 9.0 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Weber River UT16020101-027_00 Smith Morehouse River-2 13.9 Miles 3 Insufficient Data Weber River UT16020102-033_00 Snow Creek 0.0 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2022 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low pH Not meeting criteria TMDL Needed Agricultural, Recreation and Aesthetics (Infrequent Primary Contact), Aquatic Wildlife (Non-game Fish and Other) 2022 Low Weber River UT16020101-011_00 South Fork Chalk Creek 53.6 Miles 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Sediment Not meeting criteria TMDL Approved (239) Aquatic Wildlife (Cold Water) 1998 Low Total Phosphorus as P Not meeting criteria TMDL Approved (239) Aquatic Wildlife (Cold Water) 1998 Low Weber River UT16020102-032_01 South Fork Kays Creek 2.1 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2024 Low Weber River UT16020102-012_00 South Fork Ogden River 38.1 Miles 2 No Evidence of Impairment Weber River UT16020102-010_00 South Fork Ogden River-1 14.7 Miles 5 Not Supporting Assessed HNNC Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Weber River UT16020102-015_00 Spring Creek 2.4 Miles 2 No Evidence of Impairment Weber River UT16020204-034_00 State Canal 4.5 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2014 Low Total Ammonia as N Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2016 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2016 Low Weber River UT16020102-040_00 Steed Creek 1.9 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2022 Low Weber River UT16020102-046_00 Stone Creek-1 0.1 Miles 5 Not Supporting Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2016 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2016 Low Weber River UT16020102-045_00 Stone Creek-2 5.1 Miles 2 No Evidence of Impairment Weber River UT16020102-013_00 Strong Canyons Creek 1.4 Miles 2 No Evidence of Impairment Weber River UT16020102-026_03 Toll Canyon 0.1 Miles 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2014 Low Total Phosphorus as P Not meeting criteria TMDL Approved (399) Aquatic Wildlife (Cold Water) 1992 Low Weber River UT16020102-057_00 Unknown 2.4 Miles 3 Insufficient Data Weber River UT16020102-017_01 Weber Lower Tributaries-1-1 3.1 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Weber River UT16020102-017_02 Weber Lower Tributaries-1-2 38.9 Miles 3 Insufficient Data Weber River UT16020102-016_00 Weber Lower Tributaries-2 0.0 Miles 3 Insufficient Data Weber River UT16020102-021_00 Weber Lower Tributaries-3 24.6 Miles 1 Fully Supporting Weber River UT16020102-019_00 Weber Lower Tributaries-4 3.6 Miles 3 Insufficient Data Weber River UT16020102-055_00 Weber Lower Tributaries-5 27.0 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2020 Low Weber River UT16020102-054_00 Weber Lower Tributaries-6 1.1 Miles 3 Insufficient Data Weber River UT16020102-028_00 Weber Lower Tributaries-7 0.1 Miles 3 Insufficient Data Weber River UT16020102-029_00 Weber Lower Tributaries-8 0.0 Miles 3 Insufficient Data Weber River UT16020102-001_00 Weber River-1 108.7 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Waterfowl, Shorebirds, and Other), Aquatic Wildlife (Non-game Fish and Other) 2008 Low Weber River UT16020101-024_00 Weber River-10 50.5 Miles 1 Fully Supporting Weber River UT16020101-025_00 Weber River-11 39.1 Miles 1 Fully Supporting Weber River UT16020101-028_00 Weber River-12 27.7 Miles 5 Not Supporting Aluminum Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Copper Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Lead Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Weber River UT16020102-007_00 Weber River-2 0.5 Miles 2 No Evidence of Impairment Weber River UT16020102-002_00 Weber River-3 19.4 Miles 1 Fully Supporting Weber River UT16020102-020_00 Weber River-4 10.1 Miles 1 Fully Supporting Weber River UT16020102-048_00 Weber River-5 1.5 Miles 1 Fully Supporting Weber River UT16020102-022_00 Weber River-6 12.6 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Weber River UT16020101-004_00 Weber River-7 11.6 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Total Phosphorus as P Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Weber River UT16020101-017_00 Weber River-8 11.3 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Weber River UT16020101-023_00 Weber River-9 25.5 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Weber River UT16020101-006_00 Weber Upper Tributaries-1 1.5 Miles 3 Insufficient Data Weber River UT16020101-018_00 Weber Upper Tributaries-2 6.1 Miles 3 Insufficient Data Weber River UT16020101-019_00 Weber Upper Tributaries-3 23.2 Miles 2 No Evidence of Impairment Weber River UT16020101-021_00 Weber Upper Tributaries-4 10.1 Miles 2 No Evidence of Impairment Weber River UT16020102-008_00 Wheeler Creek 13.9 Miles 1 Fully Supporting West Desert UT16020306-004_00 Basin Creek 7.1 Miles 3 Insufficient Data West Desert UT16020308-002_00 Bettridge Creek 2.4 Miles 3 Insufficient Data West Desert UT16020308-008_00 Birch Creek 9.5 Miles 3 Insufficient Data West Desert UT17040211-003_00 Birch Creek - WD/C 5.4 Miles 2 No Evidence of Impairment West Desert UT16020309-002_00 Blue Creek 7.0 Miles 5 Not Supporting Boron Not meeting criteria TMDL Needed Agricultural 2020 Low E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact) 2020 Low pH Not meeting criteria TMDL Needed Aquatic Wildlife (Waterfowl, Shorebirds, and Other), Agricultural, Recreation and Aesthetics (Infrequent Primary Contact) 2012 Low Selenium Not meeting criteria TMDL Needed Aquatic Wildlife (Waterfowl, Shorebirds, and Other) 2012 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2012 Low West Desert UT17040210-006_00 Clear Creek-Sawtooth NF 19.3 Miles 3 Insufficient Data West Desert UT16020304-009_00 Clover Creek 3.5 Miles 3 Insufficient Data West Desert UT16020308-009_00 Cottonwood Creek 5.0 Miles 3 Insufficient Data West Desert UT16020309-001_00 Deep Creek 8.8 Miles 3 Insufficient Data West Desert UT16020306-005_00 Deep Creek - 1 WD/C 53.1 Miles 3 Insufficient Data West Desert UT16020308-001_00 Donner Creek 1.3 Miles 3 Insufficient Data Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC West Desert UT16020304-002_00 Faust Creek 13.6 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low West Desert UT17040211-001_01 Goose Creek-1 8.2 Miles 3 Insufficient Data West Desert UT17040211-001_02 Goose Creek-2 0.0 Miles 3 Insufficient Data West Desert UT16020306-002_00 Granite Creek 13.8 Miles 2 No Evidence of Impairment West Desert UT16020308-007_00 Grouse Creek 38.9 Miles 3 Insufficient Data West Desert UT16020301-002_00 Hamlin Valley Wash 3.3 Miles 2 No Evidence of Impairment West Desert UT17040210-005_00 Holt Creek 0.4 Miles 3 Insufficient Data West Desert UT17040210-004_00 Johnson Creek - WD/C 23.3 Miles 2 No Evidence of Impairment West Desert UT16030005-001_00 Judd Creek 3.8 Miles 3 Insufficient Data West Desert UT17040210-002_00 Junction Creek 9.7 Miles 3 Insufficient Data West Desert UT16020301-001_00 Lake Creek-Millard Co 19.5 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Aquatic Wildlife (Cold Water) 2020 Low West Desert UT16020304-007_00 Middle Canyon 4.6 Miles 3 Insufficient Data West Desert UT16020308-010_00 Muddy Creek 2.7 Miles 3 Insufficient Data West Desert UT16020304-003_00 North Willow Creek 4.2 Miles 3 Insufficient Data West Desert UT16020304-004_00 Ophir Creek 3.8 Miles 3 Insufficient Data West Desert UT16020308-004_00 Pine Creek 15.7 Miles 3 Insufficient Data West Desert UT17040211-002_00 Pole Creek 18.9 Miles 2 No Evidence of Impairment West Desert UT17040210-001_00 Raft River 24.3 Miles 2 No Evidence of Impairment West Desert UT16020308-003_00 Red Butte Creek 12.3 Miles 2 No Evidence of Impairment West Desert UT16020304-006_00 Settlement Canyon Creek 1.1 Miles 3 Insufficient Data West Desert UT16020304-005_00 Soldier Creek 6.6 Miles 3 Insufficient Data West Desert UT17040210-003_00 South Junction Creek 52.5 Miles 3 Insufficient Data West Desert UT16020304-008_00 South Willow Creek 3.5 Miles 3 Insufficient Data West Desert UT16020308-006_00 Straight Fork Creek 4.5 Miles 2 No Evidence of Impairment West Desert UT16020306-003_00 Thomas Creek 11.7 Miles 2 No Evidence of Impairment West Desert UT16020306-001_00 Trout Creek 14.4 Miles 2 No Evidence of Impairment West Desert UT16020304-001_00 Vernon Creek 13.5 Miles 5 Not Supporting pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact) 2014 Low West Desert UT16020308-005_00 Warm Creek 3.2 Miles 2 No Evidence of Impairment Western Colorado River UT14070005-015_00 Alvey Wash Lower 9.9 Miles 3 Insufficient Data Western Colorado River UT14070005-014_00 Alvey Wash Upper 0.0 Miles 3 Insufficient Data Western Colorado River UT14060009-004_02 Bear Canyon-1 1.2 Miles 5 Not Supporting but has Approved TMDL for some parameters Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2014 Low Total Dissolved Solids Not meeting criteria TMDL Approved (11137) Agricultural 2014 Low Western Colorado River UT14060009-003_04 Bear Canyon-2 1.0 Miles 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2014 Low Total Dissolved Solids Not meeting criteria TMDL Approved (11137) Agricultural 2016 Low Western Colorado River UT14070005-002_00 Birch Creek 30.3 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Western Colorado River UT14070005-018_00 Boulder Creek 58.6 Miles 3 Insufficient Data Western Colorado River UT14070007-003_00 Buckskin Gulch 2.5 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2024 Low Western Colorado River UT14070001-002_00 Bullfrog Creek 0.0 Miles 3 Insufficient Data Western Colorado River UT14070005-007_00 Calf Creek 8.1 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2008 Low Western Colorado River UT14060007-008_00 Coal Creek 31.4 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2014 Low Western Colorado River UT14070007-004_00 Cottonwood Creek 6.4 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2014 Low Not Supporting but has Approved TMDL Agricultural, Recreation and Aesthetics (Infrequent Primary Contact), Aquatic Western Colorado River UT14060009-011_00 Cottonwood Creek Lower 26.1 Miles 5 for some parameters pH Not meeting criteria TMDL Needed Wildlife (Non-game Fish and Other) 2014 Low Total Dissolved Solids Not meeting criteria TMDL Approved (11139) Agricultural 2014 Low Western Colorado River UT14060009-007_00 Cottonwood Creek Upper 21.7 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2014 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2014 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Western Colorado River UT14070005-017_00 Coyote Gulch 13.3 Miles 2 No Evidence of Impairment Western Colorado River UT14070006-005_00 Croton 2.3 Miles 3 Insufficient Data Western Colorado River UT14070005-008_00 Deer Creek (Garfield Co.) 64.9 Miles 2 No Evidence of Impairment Western Colorado River UT14060007-011_00 Desert Seep Wash 30.7 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water), Aquatic Wildlife (Waterfowl, Shorebirds, and Other), Aquatic Wildlife (Non-game Fish and Other) 2020 Low Western Colorado River UT14070004-001_00 Dirty Devil River 69.4 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2024 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2016 Low Western Colorado River UT14070004-002_00 Dirty Devil west side tributaries 11.1 Miles 1 Fully Supporting Western Colorado River UT14070003-007_00 Donkey Creek 36.4 Miles 3 Insufficient Data Western Colorado River UT14060009-001_00 Electric Lake Tributaries 17.3 Miles 3 Insufficient Data Assessed HNNC Western Colorado River UT14070005-011_00 Escalante River Lower 67.5 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2022 Low Western Colorado River UT14070005-012_00 Escalante River Upper 28.3 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2008 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2016 Low Western Colorado River UT14070005-013_01 Escalante Tributaries-1 0.0 Miles 3 Insufficient Data Western Colorado River UT14070005-013_05 Escalante Tributaries-5 0.1 Miles 3 Insufficient Data Western Colorado River UT14070005-013_06 Escalante Tributaries-6 0.0 Miles 3 Insufficient Data Western Colorado River UT14060009-012_00 Ferron Creek Lower 26.5 Miles 1 Fully Supporting Western Colorado River UT14060009-009_00 Ferron Creek Upper 104.6 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2022 Low Western Colorado River UT14070003-015_00 Fish Lake Tributaries 5.7 Miles 3 Insufficient Data Western Colorado River UT14070003-004_00 Fremont River-1 8.6 Miles 1 Fully Supporting Western Colorado River UT14070003-005_00 Fremont River-2 40.7 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Not meeting criteria TMDL Approved (R8- UT-2021-01) Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) 2020 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) 2014 Low Total Phosphorus as P Not meeting criteria TMDL Approved (4062) Aquatic Wildlife (Cold Water) 1998 Low Western Colorado River UT14070003-008_00 Fremont River-3 81.2 Miles 5 Not Supporting but has Approved TMDL for some parameters E. coli Not meeting criteria TMDL Approved (R8- UT-2021-01) Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) 2014 High Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2014 Low Western Colorado River UT14070003-014_00 Fremont River-4 82.9 Miles 4A Approved TMDL Total Dissolved Solids Not meeting criteria TMDL Approved (4063) Agricultural 1998 Low Western Colorado River UT14060007-006_00 Gordon Creek 57.6 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2020 Low Total Dissolved Solids Not meeting criteria TMDL Approved (11130) Agricultural 2014 Low Western Colorado River UT14060007-012_00 Grassy Trail Creek Lower 2.8 Miles 3 Insufficient Data Western Colorado River UT14060007-013_00 Grassy Trail Creek Upper 12.0 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Western Colorado River UT14070001-001_00 Halls Creek 0.0 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2020 Low Western Colorado River UT14070003-013_00 Henry Mountains 32.1 Miles 3 Insufficient Data Western Colorado River UT14060009-010_00 Huntington Creek-1 33.4 Miles 1 Fully Supporting Western Colorado River UT14060009-004_01 Huntington Creek-2 25.7 Miles 5 Not Supporting but has Approved TMDL for some parameters Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2014 Low Total Dissolved Solids Not meeting criteria TMDL Approved (11137) Agricultural 2024 Low Western Colorado River UT14060009-003_01 Huntington Creek-3-1 56.5 Miles 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2014 Low Total Dissolved Solids Not meeting criteria TMDL Approved (11137) Agricultural 2016 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Western Colorado River UT14060009-003_02 Huntington Creek-3-2 3.4 Miles Not Supporting but has Approved TMDL 5 for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Not meeting criteria TMDL Needed Primary Contact), Domestic Source TMDL Approved Not meeting criteria (11137) Agricultural 2014 Low Minimum Dissolved Oxygen 2014 Low pH 2014 Low Total Dissolved Solids 2016 Low Western Colorado River UT14070002-008_00 Ivie Creek Lower 16.1 Miles 5 Not Supporting but has Approved TMDL for some parameters Boron Not meeting criteria TMDL Needed Agricultural 2014 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2016 Low Total Dissolved Solids Not meeting criteria TMDL Approved (11145) Agricultural 2014 Low Western Colorado River UT14070002-004_01 Ivie Creek Upper-1 0.0 Miles 3 Insufficient Data Western Colorado River UT14070002-004_02 Ivie Creek Upper-2 28.1 Miles 2 No Evidence of Impairment Western Colorado River UT14060009-006_00 Joes Valley 44.6 Miles 3 Insufficient Data Western Colorado River UT14070003-001_00 Johnson Valley 18.4 Miles 5 Not Supporting E. coli Temperature Minimum Dissolved Oxygen Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2020 Low 2022 Low 2022 Low Western Colorado River UT14070001-005_00 Lake Canyon 0.0 Miles 3 Insufficient Data Western Colorado River UT14070006-004_00 Last Chance Creek 16.1 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Minimum Dissolved Oxygen Total Dissolved Solids Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed Aquatic Wildlife (Warm Water) Aquatic Wildlife (Warm Water) Agricultural 2008 Low 2022 Low 2014 Low Western Colorado River UT14070002-005_00 Last Chance Creek 6.6 Miles 3 Insufficient Data Western Colorado River UT14060009-002_00 LF Huntington Creek 41.2 Miles 3 Insufficient Data Western Colorado River UT14070005-019_00 Lower Escalante River Tributarie 0.0 Miles 3 Insufficient Data Western Colorado River UT14060009-005_00 Lowery Water 51.6 Miles 3 Insufficient Data Western Colorado River UT14070005-005_00 Mamie Creek 0.0 Miles 3 Insufficient Data Western Colorado River UT14060007-010_00 Miller Creek 27.5 Miles 5 Not Supporting Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2020 Low Western Colorado River UT14070002-009_00 Muddy Creek Lower 82.2 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2020 Low Western Colorado River UT14070002-006_00 Muddy Creek Middle 20.1 Miles 3 Insufficient Data Western Colorado River UT14070002-001_00 Muddy Creek Upper 80.7 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Temperature Minimum Dissolved Oxygen Total Dissolved Solids Not meeting criteria Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) Agricultural 2014 Low 2016 Low 2014 Low 2014 Low Western Colorado River UT14070001-006_00 Navajo Long Creek 0.0 Miles 3 Insufficient Data Western Colorado River UT14070005-003_00 North Creek-Escalante 49.8 Miles 5 Not Supporting Temperature Minimum Dissolved Oxygen Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Cold Water) Aquatic Wildlife (Cold Water) 2014 Low 2014 Low Western Colorado River UT14070001-093_00 North Wash 9.3 Miles 1 Fully Supporting Western Colorado River UT14070003-011_00 Oak Creek 30.3 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Western Colorado River UT14070007-001_00 Paria River-1 28.9 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Temperature Total Dissolved Solids Not meeting criteria Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed TMDL Needed Aquatic Wildlife (Non-game Fish and Other) Aquatic Wildlife (Non-game Fish and Other) Agricultural 2020 Low 2008 Low 2000 Low Western Colorado River UT14070007-002_00 Paria River-2 34.6 Miles 5 Not Supporting Temperature Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Non-game Fish and Other) Agricultural 2014 Low 2014 Low Western Colorado River UT14070007-005_00 Paria River-3 11.0 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Needed Aquatic Wildlife (Non-game Fish and Other) Agricultural 2008 Low 2014 Low Western Colorado River UT14070005-004_00 Pine Creek 33.0 Miles 3 Insufficient Data Western Colorado River UT14070003-006_00 Pine Creek (Wayne Co) 20.6 Miles 3 Insufficient Data Western Colorado River UT14060007-017_00 Pinnacle Wash 0.0 Miles 4A Approved TMDL Total Dissolved Solids Not meeting criteria TMDL Approved (11132) Agricultural 2016 Low Western Colorado River UT14070003-009_00 Pleasant Creek-1 57.9 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low Western Colorado River UT14070003-010_00 Pleasant Creek-2 10.3 Miles 3 Insufficient Data Western Colorado River UT14060007-003_00 Price River-1 82.3 Miles 5 Not Supporting Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Western Colorado River UT14060007-005_00 Price River-2 9.5 Miles 1 Fully Supporting Western Colorado River UT14060007-007_00 Price River-3 18.0 Miles 5 Not Supporting but has Approved TMDL for some parameters Boron Not meeting criteria TMDL Needed Agricultural 2014 Low Selenium Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Non-game Fish and Other) 2014 Low Draft 2024 Integrated Report: 305(b) and 303(d) Assessment unit information Associated parameter information Watershed Assessment AU Water Quality Parameter Parameter Status 303(d) Status Use(s) Cycle First Listed 303(d) Priority Management Unit Unit (AU) ID AU Name Water Size Unit Category Category Description HNNC Total Ammonia as N Total Dissolved Solids Not meeting criteria Not meeting criteria TMDL Needed TMDL Approved (11135) Aquatic Wildlife (Non-game Fish and Other) Agricultural 2014 Low 2014 Low Western Colorado River UT14060007-014_00 Price River-4 70.5 Miles 1 Fully Supporting Western Colorado River UT14060007-015_00 Price River-5 36.9 Miles 1 Fully Supporting Total Dissolved Solids Meeting criteria TMDL Approved (11131) Agricultural Western Colorado River UT14070002-007_00 Quitchupah Creek Lower 14.5 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2010 Low Total Dissolved Solids Not meeting criteria TMDL Approved (11144) Agricultural 2014 Low Western Colorado River UT14070002-002_00 Quitchupah Creek Upper 30.4 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2010 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Western Colorado River UT14060009-003_03 Rilda Canyon 0.0 Miles 5 Not Supporting but has Approved TMDL for some parameters Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2014 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2014 Low Total Dissolved Solids Not meeting criteria TMDL Approved (11137) Agricultural 2016 Low Western Colorado River UT14070002-003_00 Saleratus Creek - Emery 14.5 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2020 Low Western Colorado River UT14060009-014_00 San Rafael Lower 88.1 Miles 5 Not Supporting but has Approved TMDL for some parameters Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2010 Low Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Non-game Fish and Other) 2022 Low Total Dissolved Solids Meeting criteria TMDL Approved (11141) Agricultural Western Colorado River UT14060009-013_00 San Rafael Upper 24.4 Miles 2 No Evidence of Impairment Western Colorado River UT14070005-006_00 Sand Creek 46.1 Miles 2 No Evidence of Impairment Western Colorado River UT14070003-012_00 Sandy Creek 30.6 Miles 2 No Evidence of Impairment Western Colorado River UT14060007-002_00 Scofield Tributaries 98.5 Miles 5 Not Supporting Temperature Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2024 Low Minimum Dissolved Oxygen Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2016 Low pH Not meeting criteria TMDL Needed Agricultural, Aquatic Wildlife (Cold Water), Recreation and Aesthetics (Infrequent Primary Contact), Domestic Source 2024 Low Western Colorado River UT14060007-009_00 Soldier Creek 23.3 Miles 2 No Evidence of Impairment Western Colorado River UT14070005-010_00 The Gulch 44.5 Miles 5 Not Supporting Benthic Macroinvertebrates Bioassessments Not meeting criteria TMDL Needed Aquatic Wildlife (Warm Water) 2020 Low Western Colorado River UT14070001-094_00 Trachyte Creek 4.7 Miles 1 Fully Supporting Western Colorado River UT14070003-002_00 UM Creek 28.3 Miles 5 Not Supporting E. coli Not meeting criteria TMDL Needed Domestic Source, Recreation and Aesthetics (Frequent Primary Contact) 2020 Low Zinc Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2012 Low Not meeting criteria TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Western Colorado River UT14070003-003_00 UM Creek Lower 2.0 Miles 1 Fully Supporting Western Colorado River UT14070005-001_00 Upper Valley Creek 0.2 Miles 3 Insufficient Data Western Colorado River UT14070006-001_00 Wahweap Creek 0.1 Miles 5 Not Supporting Total Dissolved Solids Not meeting criteria TMDL Needed Agricultural 2014 Low Western Colorado River UT14070006-002_00 Warm Creek 0.0 Miles 3 Insufficient Data Western Colorado River UT14060007-001_00 White River-Colton 41.7 Miles 5 Not Supporting Threatened TMDL Needed Aquatic Wildlife (Cold Water) 2022 Low Western Colorado River UT14060007-004_00 Willow Creek - Carbon 48.3 Miles 3 Insufficient Data Western Colorado River UT14070005-016_00 Wolverine Creek 9.00E-04 Miles 3 Insufficient Data Draft 2024 Integrated Report: Delistings Watershed Management Unit Assessment Unit ID Assessment Unit Name Water Quality Parameter Delisting Reason Delisting Comment Bear River UT16010204-008_02 Bear River-2-2 Minimum Dissolved Oxygen Meeting water quality criteria with new data. Site 4901100 led to first listing in 2014IR. New data from 2020-2021 with 0/11 sample exceedances. Bear River UT16010204-006_00 Malad River-1 Total Ammonia as N Meeting water quality criteria with new data. Both impaired Sites(4902000 and 4902040) had 2/12 sample exceedances when first listed in the 2020IR. This cycle has 11 new samples with 0 sample exceedances. Jordan River UT16020204-019_00 Big Cottonwood Creek-1 E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Meeting water quality criteria Site 4994190 led to first listing in 2014. 0/5 samples exceeding criteria this cycle. Data was not assessed in 2022IR. Not even the method 200.8 samples are exceeding and that method has a higher positive bias. New data were part of a missing block of data from UPHL that was pushed to Jordan River UT16020204-023_00 Bingham Creek Selenium with new data. WQX after the 2022IR Call for Data. Jordan River UT16020204-024_02 Butterfield Creek Selenium Original listing incorrect. Site 4994420 led to first listing in 2014. The AU was split during 2018/2020IR. Site 4994420 is in UT16020204-024_01 AU. All other sites in the AU are FS or IDNE. Delist was due to a spatial site error. Jordan River UT16020204-033_00 Emigration Creek Lower E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Jordan River UT16020204-002_00 Jordan River-2 E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Jordan River UT16020204-003_00 Jordan River-3 E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Jordan River UT16020204-004_00 Jordan River-4 E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Jordan River UT16020204-005_00 Jordan River-5 E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Jordan River UT16020204-021_00 Little Cottonwood Creek-1 E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Jordan River UT16020204-024_01 Midas Creek E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Jordan River UT16020204-024_01 Midas Creek Selenium Meeting water quality criteria with new data. 0/5 samples exceeding criteria based on data from 2017-2018. Samples were part of a missing block of data from UPHL that were pushed to WQX after the 2022IR Call for data. Jordan River UT16020204-026_00 Mill Creek1-SLCity E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Jordan River UT16020204-017_00 Mill Creek2-SLCity E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Jordan River UT16020204-001_02 North Canyon Creek Minimum Dissolved Oxygen Original listing incorrect. Site 4990987 was originally listed when it was part of Jordan River-1 AU (UT16020204-001_01). Site 4990987 has been FS since 2020IR and has new data from 2020-2021. Jordan River UT16020204-025_00 Parleys Canyon Creek-1 E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Jordan River UT16020204-013_00 Parleys Canyon Creek-2 E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Jordan River UT16020204-035_00 Red Butte Creek Lower E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Jordan River UT16020204-035_00 Red Butte Creek Lower Minimum Dissolved Oxygen Original listing incorrect. Original listing applied the Early Life Stage DO Criteria incorrectly. Per IR Assessment Methods, ELS presence criteria is only applied to sites with confirmed ELS presence. For the 2022 IR, Site RB_02.16 had 6/14 sample exceedances, Site 4992084 had 6/52 sample exceedances, Site RB_04. 21 had 7/60 samples exceedances and Site RB_02.64 had 6/13 sample exceedances. Jordan River UT16020204-029_00 Rose Creek E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2023-01 Meeting water quality criteria Lower Colorado River UT15010003-005_00 Johnson Wash-2 Benthic Macroinvertebrates Bioasse with new data. New data with O/E =.93 Lower Sevier River UT16030004-003_00 Six Mile Creek - Sevier Minimum Dissolved Oxygen Original listing incorrect. Site 5943260 that triggered the listing in the 2012IR is now in UT16030004-001_00 AU. Delist due to spatial site error. Meeting water quality criteria Sites 4952400 and 4956290 were both impaired from 2012IR through the 2020IR. Site 4952400 has 0/41 sample exceedances. Site 4956290 has 0/47 sample exceedances. Data meets both chronic & Southeast Colorado River UT14030005-003_00 Colorado River-3 Selenium with new data. acute criteria. Almost half of the data is new this cycle. Meeting water quality criteria Sites 4952400 and 4956290 were both impaired from 2012IR through the 2020IR. Site 4952400 has 0/41 sample exceedances. Site 4956290 has 0/47 sample exceedances. Data meets both chronic & Southeast Colorado River UT14080201-011_00 Comb Wash Selenium with new data. acute criteria. Almost half of data is new this cycle. Southeast Colorado River UT14030005-018_00 Courthouse Wash Meeting water quality criteria Temperature with new data. 2 of the impaired samples from last cycle fell out of the POR with 10 new samples this cycle. 2 years of data have no samples exceeding. Meeting water quality criteria Site 4956390 led to first listing in 2014IR. With 15 new samples there are 0/28 sample exceedances. All other sites in the AU are FS. Multiple NPS restoration and water quality improvement projects Southeast Colorado River UT14030005-005_00 Mill Creek1-Moab Minimum Dissolved Oxygen due to restoration activities. were implemented between 2019-2021. Southeast Colorado River UT14030005-010_00 Onion Creek Lower Temperature Original listing incorrect. Site 4958280 triggered listing in 2013 with 2 samples exceeding. 12 new samples with 0/12 sample exceedances 12 samples from 2018-19 were below criteria. Site 4958285 was also listed in 1998; however, the site is 1.6 miles upstream of Site 4958280 and has been IDNE for the past four cycles. 4958280 is downstream and FS. Southeast Colorado River UT14030005-010_00 Onion Creek Lower Total Dissolved Solids TMDL Approved by EPA (4A) TMDL Action ID : 4008 Southeast Colorado River UT14030005-011_00 Pack Creek Meeting water quality criteria Selenium with new data. Site 4956460 was listed in 2010 but has not been resampled. Sites upstream (4956490 1.5mile upstream) and downstream (4956455 .5mile downstream) of originally impaired site are both FS. Draft 2024 Integrated Report: Delistings Watershed Management Unit Assessment Unit ID Assessment Unit Name Water Quality Parameter Delisting Reason Delisting Comment Southeast Colorado River UT14030005-019_00 Professor Creek Temperature Meeting water quality criteria with new data. All data collected since 2012 have been FS or IDNE. Site 4958240 is FS and is 1.6 miles down stream. It has been FS since last cycle, but has no new samples since 2019. Meeting water quality criteria Site 4934230 led to the original listing. Was assessed in 2018/20IR as IDEX. 8 samples in 2016- 2017 led to FS. The 2016-2017 data were not part of the 2022IR data package and were not Uinta Basin UT14060003-005_00 Antelope Creek Selenium with new data. assessed Meeting water quality criteria Site 4939490 led to first listing in 2014. Based on 2016-2017 data for this site, 0/10 sample exceedances. The data were part of a missing block of data from UPHL and were pushed to WQX Uinta Basin UT14040107-005_00 East Fork Smiths Fork Zinc with new data. after the 2022IR Call for data. Uinta Basin UT14060008-002_00 Green River-5 Temperature Meeting water quality criteria with new data. The impaired site 4930150 from the 2022IR had 3/20 sample exceedances. 15 new samples for current POR with 3/34 sample exceedances. Uinta Basin UT14060004-002_00 Indian Canyon Creek Selenium Meeting water quality criteria with new data. Site 4934530 triggered impairment in 2014. 0/27 sample exceedances. Data were not accepted nor rejected for the 2022IR cycle. Uinta Basin UT14040106-021_00 Pot Creek E. coli Meeting water quality criteria with new data. All assessed data from Site 4926360 is new data from the past 2 years. All impaired samples are out of the 2024IR POR. Upper Provo River UT16020203-016_00 McHenry Creek Cadmium Meeting water quality criteria with new data. Site 4997675 triggered the impairment in the 2016IR. 18 new samples allowed for the assessment of the chronic criteria with 1/24 sample exceedances. Upper Provo River UT16020203-004_00 Provo River-4 pH Original listing incorrect. Impaired site now in a different AU. The Spring Creek-Heber AU was redrawn to include all of Rock Creek. Site UTAHDWQ_WQX-4997314 that was in UT16020203-004_00 PR-4 is now in UT16020203-027_00. Delist due to spatial site error. Upper Provo River UT16020203-027_00 Spring Creek-Heber E. coli TMDL Approved by EPA (4A) TMDL Action ID : R8-UT-2022-01 Upper Sevier River UT16030002-002_00 Otter Creek-1 Benthic Macroinvertebrates Meeting water quality criteria Bioasse with new data. New sample O/E>.8 which is above the .76 threshold. Upper Sevier River UT16030001-007_00 Sevier River-2 Benthic Macroinvertebrates Meeting water quality criteria Bioasse due to restoration activities. New samples from 2020 put the O/E= 0.87. Delin Roundy Stream Bank Restoration project near sampled Site 4949642. Weber River UT16020102-036_00 Baer Creek-3 pH Meeting water quality criteria with new data. 3/21 samples exceeded in the 2022IR. There are 10 new samples with 3/31 samples exceeding but below 10% exceedance threshold. Weber River UT16020102-026_01 East Canyon Creek-2-1 Total Dissolved Solids Meeting water quality criteria with new data. Site 4925370 tripped the TDS listing but has not been resampled since 2014IR due to access issues. Site 4925410 is 500 ft downstream and is fully supporting. This site and all other sites in the AU are supporting. Weber River UT16020102-031_00 Kays Creek Total Dissolved Solids Meeting water quality criteria with new data. Impaired Site 4990110 had 3/22 sample exceedances during the 2022IR POR. For this cyle, there were 11 new samples with only 2/21 sample exceedances. Weber River UT16020101-020_01 Silver Creek-1 Nitrate as N Original listing incorrect. Original Nitrate impairment was due to Site 4926740 in UT16020101-020 AU. The AU was split and Site 4926740 now resides in UT16020101-020_02 AU. Delist due to spatial site error. Weber River Weber River UT16020101-020_02 UT16020101-020_02 Silver Creek-2 Silver Creek-2 Nitrate as N Total Dissolved Solids Meeting water quality criteria with new data. Meeting water quality criteria with new data. Site 4926740 was first listed in the 2014IR. Data from 2015-2016 had 4/12 sample exceedances for the 1C use and 10/12 sample exceedences for the 2B and 3A use. New samples from 2021-2022 show 0/11 sample exceedances. Silver Creek WRF was upgraded, including nitrogen removal. Sites 4926740,4926800,4926850,4926950 were first listed in the 2010IR. All 4 sites have new data from 2021-2022 and are now FS. Weber River UT16020101-011_00 South Fork Chalk Creek E. coli Meeting water quality criteria due to restoration activities. All assessed data from Site 4926360 is new data from the past 2 years. All impaired samples are out of POR. Rangeland grazing improvement awarded in AU in 2018. Western Colorado River UT14060009-010_00 Huntington Creek-1 Selenium Meeting water quality criteria with new data. New data. Site 4930518 has 0/13 samples exceedances and Site 4930520 has 0/16 sample exceedances. Last samples exceeding were in 2012. Western Colorado River UT14060007-015_00 Price River-5 Total Dissolved Solids Meeting water quality criteria with new data. Site USGS-9314500 first listed in 2016. Site is at the same location and was merged/assessed with Site UTAHDWQ_WQX-4931650 with 3/68 sample exceedances. Western Colorado River UT14060009-014_00 San Rafael Lower Total Dissolved Solids Meeting water quality criteria with new data. Sites USGS-09328500 and 4930270 both led to the impairment in the 2016IR but are now meeting criteria with new data. Site 4930270 has 1/13 sample exceedances. Site USGS-09328500 has 2/70 sample exceedances. Western Colorado River UT14070006-001_00 Wahweap Creek Temperature Meeting water quality criteria with new data. Site 5994530 led to the impairment in the 2014IR. Now, 3/40 sample exceedances. 86 Appendix 1 Data Quality Guideline Examples DWQ Sampling Analysis Plan Requirements Revision 2 January 1, 2017 Utah Division of Water Quality Checklist of Essential Elements for Sampling and Analysis Plans (SAPs) Monitoring Project/Program: Preparer(s): Reviewer(s): Date Submitted for Review: Date of Review: Parent QAPP or Equivalent Document: Instructions for Preparers: As required by DWQ’s Quality Assurance Program Plan for Monitoring Programs (DWQ QAPP), any monitoring activity conducted or overseen by DWQ must have a SAP, excluding one-time response actions (such as a spill) or compliance sampling. The SAP must be reviewed and revised for each field season/monitoring year. SAPs are approved and kept on file by the Monitoring Section QA Staff and must be distributed to everyone involved with a monitoring project. Provided below is a template and checklist to create a SAP. The SAP should contain or reference all the elements in this checklist but need not have the same format. Rather than extensive text, include as much information as possible in the form of tables, which are easier to refer to in the field. The SAP should be a usable, stand-alone document that can be taken into the field by Monitors. Definitions and Acronyms: DPM - Designated Project Manager. As defined by DEQ’s Quality Management Plan (QMP), the DPM is the staff member responsible for a specific project and has immediate managerial or technical control of that project. The DPM is responsible for specifying the quality of the data required for each project and initiating corrective actions when quality control is not being met. The DPM may also be a program manager. The DPM is responsible for designing monitoring strategies, setting project- specific data quality objectives (DQOs), and developing project-specific SAPs. DPMs are responsible for making sure all personnel involved with the project are briefed and/or trained on the procedures to be used. Roles of DPMs are further discussed throughout the DWQ QAPP. IR-Integrated Report SMP – Strategic Monitoring Plan Introduction and Background Information (This can be brief if it references some previous documentation or the IR or SMP, etc.) 87 • Site history • Regulatory framework • Summary of previous investigations • Location/characteristics of any known pollution sources at the site or in the area • Site location map showing area at a broad scale Objectives and Design of the Investigation (This should be very specific to the project and should be a result of discussions between DPM, data users, stakeholders, science panel, etc.) • Specific objectives of this study (describe how they support broader program goals/objectives or regulatory framework) • Provide the study design (i.e. spatial/temporal limits, sample characteristics, the smallest population, area, volume, or time frame for which decisions will be made). • Discuss representative sampling conditions and instructions for field personnel if they encounter non- representative sampling conditions • Describe parameters of concern (narrative – must conform to list(s) in sections 4 and 6) • Number, location, and frequency of samples and quality control samples • Sampling Site Locations • Rationale for site selection • Site map(s) showing sampling locations and “control” sites and any other pertinent features such as land use, etc. within the sampling area Special Precautions and Safety Plan • Detailed itemization of any specific safety concerns • Reference to an applicable safety plan • Any additional safety training required for project • Documentation that field personnel comply with your Invasive Species Plan and SOPs to prevent spread of invasive species Field Sampling Methods and Documentation • Any special training needed beyond those discussed in DWQ QAPP and where training documentation will be kept • Include a table listing each field instrument to be used (equipment, describe operation or indicate where operation manual is kept for field event, include calibration procedures, if any) • Include a table listing each sampling method to be used (sampling equipment if needed, cite method in SAP, attach applicable SOPs) • For any sampling equipment used, describe operation of any sampling equipment used or location of operation manual for field event, include decontamination procedures, if any, attach applicable SOPs • If not found in SOPs, include equipment lists and sampling trip organizing checklists if not found in SOPs • List corrective actions for problems that may occur in the field • Discuss what field documentation is required and how field records shall be generated and stored Laboratory Sample Handling Procedures • Describe sample containers, preservatives, holding times 88 • Describe field documentation (COC) and sample labeling procedures • Describe shipping plan for sample transport to laboratory Analytical Methods and Laboratory Documentation • Chemical – list parameter, cite preparation method and analytical method, list required sensitivity or detection limits • Biological – cite method or desired taxonomic level and organism target count, etc. • Required reporting procedures (e.g. hardcopy, electronic deliverables) and turn-around times • Be sure DWQ has obtained QA documentation for each laboratory used (check with Monitoring Section QA Staff), reference this information and any new/research analytical methods being used (obtain these protocols if available from lab) • List the required data package contents from the analyzing laboratories [or reference a service contract or Memorandum of Understanding (MOU)] Project Quality Control Requirements • Table of QC limits for field instruments (operation range, accuracy, and precision) • Table listing each Data Quality Indicator (precision, accuracy, bias, etc.), how it will be measured, and the performance criteria against which it will be evaluated (use the table in the DWQ QAPP and adapt it to this project if needed): (1) analytical (internal to lab) QC limits for chemical analyses (acceptable precision, accuracy, and negative control – lab method blank, (2) field sample QC limits for chemical analyses [Acceptable precision (field duplicates) and negative control (field or trip blanks)], and (3) QC limits for biological analysis [Acceptable precision (% diff in enumeration, 5 taxonomic difference)] • QC limits, schedule, and descriptions of planned field/lab audits/assessments • Data quality assurance review procedures: (1) describe system of data qualification, (2) describe measure of completeness relative to planned design, and (3) corrective actions for non-conformance Data Analysis, Record Keeping, and Reporting Requirements • Data interpretation approach (include means to temper decision-making if limited completeness of design occurs) • Describe project record keeping procedures and archive (hardcopies, electronic data) • Describe how and when DPM wishes to be notified of available laboratory/field results • Describe expected content and format of final project report and who will receive original/copies. Schedule and Budget • Table or figure showing project schedule with key project milestones • List funding sources for project and include anticipated equipment, consumables, personnel purchases/costs • Sample costs/lab resources per fee schedule Project Team and Responsibilities • Identify project team responsibilities and personnel • Identify sampling personnel • Identify subcontractors (e.g. chemical and biological labs) References (include references to DWQ-prepared documents) 89 Appendices and Attachments (include SOPs, Chain of Custody forms, Field Forms, Sample Labels, etc.) 90 Example Field Observation Form for Grab Samples 91 Appendix 2 Application of Secondary Review Process The table below contains a set of data considerations and concerns that may prompt a change to an assessment unit category during the secondary review process. Data Concern Secondary Review Process Data Application Temporal variation within a dataset Insufficient sampling frequency within an assessment period of record Individual data records Bias in sampling design (1) Event monitoring (review flow, weather, and spill/response/incident data; narrative criteria; field observations and photographs; satellite imagery; other data types collected in same (and around the) period of concern, etc.), (2) sample time of day (literature review to determine if parameter is impacted by the time of day sample is collected), (3) sampling a specific season (unless approved by DWQ in a SAP or is data- type specific (e.g., E. coli sampling during the recreation season)], (4) and locational bias Individual data records Data quality (1) Quality Assurance Program Plan For Environmental Data Operations, (2) field calibration documentation, (3) laboratory methods, (4) standard operating procedures, (5) demonstration of capability (if applicable to data type), and (6) discussion with sample collector Individual data records, and/or, parameter(s) in period of record, and/or monitoring location Wrongly monitored (1) Measured point source (vs. main water body), review imagery of area, flow, etc., (2) waterbody type DWQ does not assess, (3) grab sample vs. composite, (4) flow conditions (too low or not flowing), and (5) field observation that impacts quality of data Individual data records and/or monitoring location Outlier (1) Need more than a statistical test. Should be based on scientific or QA basis, (2) QA/QC field sampling blanks, duplicates/replicate, (3) laboratory Analytical Batch QC, (4) value is nonsensical (e.g., cannot be measured with field/laboratory method), and (5) refer to data quality (above) Individual data records 92 Magnitude of exceedance (1) Significant figures and (2) narrative criteria review Individual data records QA/QC concerns (1) Holding time, (2) laboratory comment, (3) dilutions, spikes, and (4) other laboratory QC performance checks Individual data records Data Concern Secondary Review Process Data Application Assessment unit grouping/spatial variation (1) Multiple locations not grouped correctly (either should or should not have been grouped), (2) AUs where water quality criterion exceedances are clearly isolated to a relatively small, hydrologically distinct portion of the larger AU and may need to be re-segmented to more accurately reflect that variation in water quality (please refer to 303(d) Assessment Methods section on “Assessment Unit Re-segmentation” for more information on the process), and (3) a surface water (e.g., a spring or seep) was sampled in the AU and was assessed but additional information indicates that the surface water may not have been flowing or did not connect, contribute, or influence downstream water quality Monitoring location Credible data (1) Data type applied incorrectly and (2) data type not considered. (Data type must meet credible and representative data requirements in 303(d) Assessment Methods, and if included in the assessment analysis would result in a change in the categorization of the waterbody and parameter Individual data records and/or parameter(s) in period of record, monitoring location Other (1) Parameters wrongly grouped (by CAS, fraction, or methods), (2) data type is laboratory measurement (when the data assessment requires a field measurement), (3) IR QA/QC flagged data, and (4) errors in standards Individual data records. Entire parameter assessments Conflicting DO assessments between grab and high frequency data Scenario: Two types of data available at the site(s) (i.e., grab or high frequency data) do not have the same preliminary assessment result. Reviews to consider: (1) sampling period captured, (2) duration of conditions below criterion, (3) frequency of recurrent low DO events, (4) magnitude of exceedance, (5) spatial extent of low DO, and (6) diel flux of DO Individual data records. Entire parameter assessments 93 Representativeness and Environmental Factors* Examples of extreme events include the following: (1) accidental spills of toxic chemicals, (2) scouring storm flows that lead to diminished aquatic-life beneficial uses, and (3) extreme drought conditions. Given the scope of these assessments, it is not always possible to identify where such circumstances may be influencing a specific sample, but DWQ will consider any evidence presented that a sample is not representative of ambient conditions. Examples of such a review may include reviewing flow, weather, spill data, narrative criteria, field observations and photographs, satellite imagery, other data types collected in the same (and around the) period of concern, etc. Individual data records Data Concern Secondary Review Process Data Application Pollution Indicators Secondary reviewers will incorporate indicator data into assessment category determinations, relying on multiple lines of evidence, including pollution indicator thresholds, the presence or absence of other indicator-associated water quality issues, potential pollutant sources, and other site or watershed-specific knowledge to determine whether listing or delisting on a pollution indicator parameter is appropriate or whether to prioritize waterbodies for additional monitoring. (1) Pollution indicator evaluations will be posted with the report(s (e.g. exceedance counts & frequencies), so DWQ programs and stakeholders can consider the results when planning for future monitoring, studies, evaluations, etc, (2) pollution Indicator evaluations may be included in a narrative assessment/standard not supporting or supporting assessment decision, (3) pollution indicators may be reported by the IR as a cause of pollution impairment, and (4) pollution indicators may be reported by the IR as the source of an impairment 94 *Footnote: Where these conditions are present in a dataset, DWQ will run the analysis without the extreme events/data record and will apply and document an appropriate assessment result for the waterbody using the methods outlined below. Category 1: Supporting: If analyses with and without the extreme events are supporting (Category 1. Category 2: No evidence of impairment: If analyses with the extreme events are supporting (Category 1), but the analyses without the extreme events show no evidence of impairment (Category 2) Category 2: No evidence of impairment: If analyses with and without the extreme events do not indicate evidence of impairment (Category 2) Category 2: No evidence of impairment: If analyses with the extreme events are evidence of impairment (Category 3 with exceedances), but the analyses without the extreme events show no evidence of impairment (Category 2) Category 2: No evidence of impairment: If analyses with the extreme events are not supporting (Category 5), but the analyses without the extreme events show no evidence of impairment (Category 2) Category 3: Insufficient Data, Exceedances: If analyses with and without the extreme events show evidence of impairment (Category 3) Category 3: Insufficient Data, Exceedances: If analyses with the extreme events are not supporting (Category 5), but the analyses without the extreme events are supporting (Category 1) Category 5: Not supporting: If analyses with the extreme events are evidence of impairment (Category 3), but the analyses without the extreme events are not supporting (Category 5) Category 5: Not supporting: If analyses with the extreme events are not supporting (Category 5), but the analyses without the extreme events show evidence of impairment (Category 3) Category 5: Not supporting: If analyses with and without the extreme events are not supporting (Category 5) 95 Appendix 3 Summarizing Assessments From Site to Assessment Unit Level This appendix uses a theoretical assessment unit (see Figure 28 below) to demonstrate how DWQ composes the overall assessment unit category using site-level parameter assessments of beneficial use support. The assessment unit (AU) below has four monitoring locations and two beneficial uses. In this example, the AU has been sampled for two water quality parameters: temperature and pH. Each heading below corresponds to a table demonstrating the scenario described. In each table, NS means not supporting (or not meeting criteria; impaired), FS means fully supporting (or meeting criteria), and ID means insufficient data. Not Supporting (EPA Category 5) The AU is categorized as not supporting if ANY site within the AU is not supporting for one or more parameters that are not covered under a TMDL or other pollution control mechanism. In the example scenario below, Site A is not supporting beneficial use 1 based on temperature criteria, but the AU has a TMDL for temperature. Sites B and D are not supporting beneficial use 2 based on pH criteria, and there is no TMDL in place to address pH. Site C is fully supporting beneficial use 1 based on temperature criteria. Because the AU has sites that are not supporting for a parameter that does not have an existing TMDL in place (rows highlighted in orange), the AU has the overall EPA Category 5. Note that this example is intended to show how Category 5 supersedes a TMDL Category 4A in an assessment unit, but any assessment unit with site- use-parameter combinations that are not supporting one or more beneficial uses and have no TMDL associated with any parameters would also fall under Category 5. Figure 28. Process of composing overall AU category using site-level parameter assessments of beneficial use support. 96 Assessment Unit Decision: Category 5 (Not supporting) for beneficial use 2 based on pH assessment and Category 4A for beneficial use 1 based on temperature assessment. Temperature is associated with an existing TMDL. TMDL Approved (EPA Category 4A) The assessment unit falls in the TMDL approved category if it is not supporting for one or more parameters at one or more sites for which the assessment unit has an approved TMDL. In the example scenario below, Site A is not supporting beneficial use 1 for temperature, but there is a TMDL associated with temperature in that assessment unit (row highlighted in green). Note that site C is fully supporting beneficial use 1 based on temperature criteria, but it is still covered by the AU’s temperature TMDL. Because all other beneficial uses and parameters are fully supporting at sites within the AU, the overall AU category is EPA Category 4A. Assessment Unit Decision: Category 4A (Approved TMDL) for beneficial use 1 based on temperature assessment. Insufficient Data (EPA Category 3) The assessment unit falls into the insufficient data category if an assessment has not been performed on ANY parameters at ANY of the sites in the assessment unit. In the example scenario below, all sites had data associated with either pH or temperature, but not enough data were collected (based on 303(d) assessment methods) at any site over the period of record to fully assess the site-use-parameter combination (all rows highlighted in blue denoting the site-use-parameter-level insufficient data assessment category). In this case, the overall AU category is EPA Category 3. DWQ also keeps track of any water quality samples that exceeded numeric criteria. These site-use-parameter combinations are usually prioritized for further sampling and a full assessment. 97 Assessment Unit Decision: Category 3 (Insufficient Data) based on both beneficial uses and parameter assessments at all four sites. No Evidence of Impairment (EPA Category 2) The assessment unit falls into the no evidence of impairment category if at least one use at one or more sites has been assessed and is fully supporting, but one or more uses have not been assessed at ALL sites within the AU. In the example scenario below, sites A, B, and C were sampled for temperature, which is used to assess support for beneficial use 1. Sites A, B, and D were sampled for pH, which is used to assess support for beneficial use 2. At sites A and B, enough pH data were collected to perform assessments of beneficial use support for use 2. Only one full assessment of beneficial use support at one site is required to represent a full assessment of beneficial use support for the AU. However, no site had enough data to fully assess temperature and thus beneficial use support for use 1 (rows highlighted in olive green). Because the AU beneficial use category for use 1 is insufficient data and the beneficial use category for use 2 is fully supporting, the overall assessment unit category is EPA Category 2, no evidence of impairment. Note that in this case, impairment and not supporting are synonymous terms. Assessment Unit Decision: Category 2 (No Evidence of Impairment) due to full support of beneficial use 1 based on the pH assessments and insufficient data to assess beneficial use 2 across all sites. Fully Supporting (EPA Category 1) The assessment unit is fully supporting if all uses have been assessed at AT LEAST one site (Table 5). Note that in this scenario, a site does not need to be fully assessed for all uses, but the AU must contain sites for which each use was fully assessed. In the example scenario below, use 1 was fully assessed using temperature data at Site A, and use 2 was fully assessed with pH data at Site B. Although some site-use- parameter level datasets had insufficient data to be fully assessed, both beneficial uses were fully assessed at one or more sites within the AU (rows highlighted in light blue), and can be used together to represent a full assessment of the AU’s beneficial uses. 98 Assessment Unit Decision: Category 1 (Fully Supporting) for beneficial uses 1 and 2 based on fully supporting pH and temperature assessments at sites within the assessment unit. 99 Appendix 4 4B Submission Policies and Procedures: Process for Determining Category 4B Classification An approved Category 4B demonstration plan is an alternative to listing an impaired segment on the state’s 303(d) list. A Category 4B demonstration plan, when implemented, must ensure that all applicable water quality standards are met through agreed-upon pollution-control mechanisms within a reasonable time period. These pollution-control mechanisms can include approved compliance schedules for capital improvements or plans enforceable under other environmental statutes (such as Comprehensive Environmental Response, Compensation, and Liability Act) and their associated regulations. A Category 4B demonstration can be used for segments impaired by point sources and/or nonpoint sources. Both DWQ and EPA must accept a Category 4B demonstration plan for the affected segment to be placed in Category 4B. In the event that the Category 4B demonstration plan is not accepted, the segment at issue will be included on the 303(d) list, Category 5. Generally speaking, the following factors will be considered necessary for Category 4B demonstration plan acceptance: 1) appropriate voluntary, regulatory, or legal authority to implement the proposed control mechanisms through permits, grants, compliance orders for Utah Pollutant Discharge Elimination System permits, etc.; 2) existing commitments by the proponent(s) to implement the controls; 3) adequate funding; and 4) other relevant factors appropriate to the segment. The following evidence must be provided as a rationale for a Category 4B demonstration plan: A statement of the problem causing the impairment 1. A description of a. The pollution controls to be used b. How these pollution controls will achieve attainment with all applicable water quality standards c. Requirements under which those pollution controls will be implemented 2. An estimate of the time needed to meet all applicable water quality standards. 3. A schedule for implementation of the necessary pollution controls. 4. A schedule for tracking progress, including a description of milestones. 5. A commitment from the demonstration plan proponent to revise the implementation strategy and pollution controls if progress toward meeting all applicable water quality standards is not shown. Timing for proposal submittal and acceptance by DWQ and EPA • Category 4B demonstration plans should be submitted to DWQ by July 1 of even numbered years, in order for DWQ to submit the plan to EPA by September 1 of even numbered years. Parties are encouraged to work with DWQ before this date as states are the entity required to submit these plans to EPA. 100 • Acceptance from EPA must be obtained by October 31 of even numbered years; otherwise, DWQ will continue to propose that the segment in question is included on the current cycle’s 303(d) list. • If EPA and DWQ accept the Category 4B plan, DWQ will notify the Water Quality Board and the public through proposed statement of basis and purpose language in its proposal that a Category 4B demonstration plan is accepted and is appropriate for this segment. EPA has several documents that contain additional information on Category 4B demonstration requirements, including: “2006 Integrated Report Guidance”; and “Information Concerning 2008 Clean Water Act Sections 303(d), 305(b), and 314 Integrated Reporting and Listing Decisions”. 101 Appendix 5 Delisting Guidelines DWQ must follow a consistent, well-documented delisting process to be approved by the EPA each cycle. The guidelines below outline the questions and scenarios DWQ considers when analyzing whether sufficient evidence exists to delist a waterbody for one or more pollutants. Does the AU/AU-parameter combination warrant further investigation? (See 303(d) Assessment Methods for more details). • Generally, this means that the AU was previously listed for one or more parameters that were not meeting criteria, but in the current assessment, parameter data are meeting criteria and fully supporting at the site- level. What was the original cause of impairment for the AU? What beneficial use was assessed? Is it the correct beneficial use? What IR assessment cycle was the AU and parameter first listed? • What datasets were used for that listing (e.g., the agency/sample collector)? • What was the period of record? (If unknown, use the longer period of record). • What MLIDs are in the AU? For impairments listed in a previous assessment cycle, compile data from all MLIDs in the AU, regardless of waterbody type. Which MLID(s) have/had exceedances in the pollutant of interest? • For MLIDs with impairments/exceedances that were not assessed in the current IR cycle, determine why the site was not resampled. If the AU is a delisting candidate, provide documentation as to why resampling was not done and why the site should meet water quality standards. Please refer to the good cause descriptions in the 303(d) methods. If the delisting reason does not demonstrate good cause, the documentation will need to be EPA-approved. • For MLIDs with historical or current impairments/exceedances assessed in the current IR cycle, DWQ will typically not delist an AU where the current parameter assessment for the MLID(s) is not fully supporting. However, DWQ will consider delisting when a secondary review applied to the parameter, MLID, or AU places it in the fully supporting category (or no evidence of impairment at the AU-level). The secondary review justification will need to be EPA-approved and checked for good cause. • Determine if the current parameter assessment is fully supporting (no secondary review applied to this parameter) and check for good cause. Consider: What is the oldest date in that period of record for that MLID/Parameter combo in the current assessment cycle? • Note: Confirm that if no new data are collected, the new assessment analysis is not fully supporting because the exceedances are out of the period of record for assessment analysis. This is not a delisting. EPA Delisting Codes Delisting Reason Code Comment WQS_NO_LONGER_THREATENED Applicable WQS attained; threatened water no longer threatened WQS_NEW_ASMT_METHOD Applicable WQS attained, according to new assessment method DELISTING_4C Not caused by a pollutant (4c) DELISTING_WQS_NOT_APPLICABLE WQS no longer applicable DELISTING_4B Other pollution control requirements (4b) DELISTING_4A TMDL Approved or established by EPA (4a) WQS_NEW_DATA Applicable WQS attained; based on new data WQS_LISTING_INCORRECT Applicable WQS attained; original basis for listing was incorrect REFINEMENT Clarification of listing cause WQS_RESTORATION_ACTIVITIES Applicable WQS attained, due to restoration activities WQS_RECOVERY_UNSPECIFIED Applicable WQS attained; reason for recovery unspecified DELISTING_NOT_IN_JURISDICTION Listed water not in state's jurisdiction WQS_STANDARDS_CHANGED Applicable WQS attained, due to change in WQS NOT_SPECIFIED Not specified DELISTING_NOT_WATER_OF_STATE Water determined to not be a water of the state DELISTING_ORIG_INCORRECT Data and/or information lacking to determine WQ status; original basis for listing was incorrect Appendix 6 Response to Comments: 303(d) Assessment Methods The following are public comments received for the 2024 303(d) Assessment Methodology and the Utah Division of Water Quality’s (DWQ) response. Please click the links below to jump to your section of interest. Daniel Lay Comment 1A: Identifying Causes of Impairments DWQ Response to comment 1A: Rob Dubuc, Friends of Great Salt Lake Comment 2A: Assessments Specific to Lakes and Reservoirs DWQ Response to comment 2A: Grant Wilson, Earth Law Center Comment 3A: Revising the 303(d) List and Other Categorical Assessments DWQ Response to comment 3A: Comment 3B: Revising the 303(d) List and Other Categorical Assessments DWQ Response to comment 3B: Shera Reems, EPA Region 8 Comment 4A: Assessments Specific to Rivers, Streams, and Canals, Table 11 DWQ Response to comment 4A: Comment 4B: Assessments Specific to Rivers, Streams, and Canals, Table 11 DWQ Response to comment 4B: Comment 4C: High Frequency Assessments for Dissolved Oxygen (DO) DWQ Response to comment 4C: Comment 4D: Nutrient Assessments Specific to Headwater Streams (Pages 40 to 41) DWQ Response to comment 4D: Comment 4E: Assessments Specific to Lakes, Reservoirs, and Ponds, Aquatic Life Use Support, Figure 9 (Page 49) DWQ Response to comment 4E: Comment 4F: Temperature and Dissolved Oxygen: Stratified Lakes and Reservoirs, Figure 12 (Page 52) DWQ Response to comment 4F: Comment 4G: Great Salt Lake (Pages 56 to 57) DWQ Response to comment 4G: Comment 4H: Harmful Algal Blooms (Pages 66 to 67) DWQ Response to comment 4H: Comment 4I: Harmful Algal Blooms (Pages 66 to 67) DWQ Response to comment 4I: Ellen Bailey, DWQ Comment 5A: Harmful Algal Blooms DWQ Response to comment 5A: Ashley A. Peck, Wasatch Front Water Quality Council Comment 6A: Harmful Algal Blooms DWQ Response to comment 6A: David Richards, OreoHelix Ecological Comment 7A: Biological Assessments, Figure 7 DWQ Response to comment 7A: Comment 7B: Biological Assessments, reliance on O/E as sole indicator of biological integrity DWQ Response to comment 7B: Comment 7C: Biological Assessments, definition of biological integrity DWQ Response to comment 7C: Comment 7D: Biological Assessments, O/E Reference Sites DWQ Response to comment 7D: Comment 7E: Biological Assessments, loss of predicted taxa DWQ Response to comment 7E: Comment 7F: Biological Assessments, probability of capture >50% DWQ Response to comment 7F: Comment 7G: Biological Assessments, RIVPACS O/E precision and predictive ability DWQ Response to comment 7G: Comment 7H: Biological Assessments, Figure 8 DWQ Response to comment 7H: Comment 7I: Biological Assessments, incorporation of 1st and 8th+ order streams and rivers DWQ Response to comment 7I: Comment 7J: Biological Assessments, taxonomic resolution DWQ Response to comment 7J: Comment 7K: Biological Assessments, seasonality effects DWQ Response to comment 7K: Comment 7L: Biological Assessments, reliance on PRISM data DWQ Response to comment 7L: Comment 7M: Biological Assessments, Implications of evenness on O/E Scores and UDWQ Bioassessments DWQ Response to comment 7M: Daniel Lay Comment 1A: Identifying Causes of Impairments Absence or lack of water in perennial systems due to drought, over-allocation of water rights, debris flows/wildfire should be considered a class 4C non-pollutant impairment. DWQ Response to comment 1A: As described in the assessment methods (page 12, Table 1 and page 74, Category 4C), DWQ may place a waterbody or parameter-specific impairment in category 4C when DWQ can demonstrate that a beneficial use impairment is driven by pollution and not by a pollutant or pollutant that causes pollution; including use impairments driven by hydrologic modification. DWQ recognizes the potential negative impacts hydrologic modification may have on beneficial use attainment and is currently actively engaged in an internal workgroup focused on improving our ability to identify, quantify, and evaluate the impacts of hydrologic modifications on beneficial use attainment in Utah. No method changes are required for DWQ to place impairments driven by hydrologic modification in category 4C. Stakeholders with information or evidence demonstrating that a beneficial use impairment is related to hydrologic modification may submit that information for review during the 2024 Integrated Report public comment period. Rob Dubuc, Friends of Great Salt Lake Comment 2A: Assessments Specific to Lakes and Reservoirs Specific to Great Salt Lake: The Division should develop a method for assessing GSL salinity. DWQ Response to comment 2A: DWQ is conducting an evaluation of the current status and trends of water levels, salinity, habitat availability, and aquatic biota in Gilbert Bay to develop appropriate assessment methods. Without defined numeric criteria, it is challenging to develop and implement clearly defined and repeatable assessment methods for assessing whether Great Salt Lake’s Bays’ including Gilbert Bay are meeting their beneficial uses. Therefore, new assessment methods for Great Salt Lake, including for salinity, have not been incorporated into the 2024 Integrated Report. Grant Wilson, Earth Law Center Comment 3A: Revising the 303(d) List and Other Categorical Assessments ELC has advocated for complete and accurate 303(d) lists and 305(b) reports for ten years, including in Utah. As you know, we were pleased that there were several flow-impaired waters listed under Category 4C in Utah’s 2022 Integrated Report. We also sincerely appreciate the ongoing dialogue and DWQ's openness to form a workgroup to evaluate potential methodologies to assess non-pollutant pollution impairments. We understand this will not be completed before the 2024 303(d) assessment method public comment period this fall. While these are all positive developments, we still urge you to include a simple statement allowing for Category 4C listings under a "weight of the evidence" approach in the 2024 Integrated report. Drawing inspiration from the "weight of evidence" approach used for Category 5 waters in California, the methodology could look something like this: When readily available information strongly indicates the non-attainment of water quality standards due to hydrological modification (i.e., 4C waters), a water segment shall be evaluated to determine whether the weight of evidence demonstrates that a water quality standard is not attained and, therefore, a listing is appropriate under Category 4C. When making a listing decision based on the situation-specific weight of evidence, the DWQ must justify its recommendation by: • Providing any data or information including current conditions supporting the decision; • Describing in fact sheets how the data or information affords a substantial basis in fact from which the decision can be reasonably inferred; • Demonstrating that the weight of evidence of the data and information indicate that the water quality standard is not attained; and • Demonstrating that the approach used is scientifically defensible and reproducible. Additionally, or in the alternative, the DWQ could commit to piloting a "weight of the evidence" approach for Category 4C listings beginning with those rivers that flow into the Great Salt Lake. As you know, the Great Salt Lake is undergoing an imminent ecological crisis in large part due to low inflows from the Jordan, Weber, and Bear rivers. Listing these rivers for Category 4C hydromodification, assuming such a listing is justified under a "weight of the evidence" approach, would send a strong message that the DWQ is using all available policy tools to help address one of the greatest, existential challenges facing Utah. DWQ Response to comment 3A: As described in the assessment methods (page 12, Table 1 and page 74, Category 4C), DWQ may place a waterbody or parameter-specific impairment in category 4C when DWQ can demonstrate that a beneficial use impairment is driven by pollution and not by a pollutant or pollutant that causes pollution; including use impairments driven by hydrologic modification. As the commenter notes, DWQ is currently actively engaged in an internal workgroup focused on improving our ability to identify, quantify, and evaluate the impacts of hydrologic modifications on beneficial use attainment in Utah. The commenter’s suggestions have been provided to that workgroup. No methods changes are required for DWQ to place impairments driven by hydrologic modification in category 4C in the manner recommended by the commenter, and the data and information used to make assessment decisions, including potential 4C determinations are published as part of the Integrated Report and available for public comment. Stakeholders with information or evidence demonstrating that a beneficial use impairment is related to hydrologic modification may submit that information for review during the 2024 Integrated Report public comment period. Comment 3B: Revising the 303(d) List and Other Categorical Assessments Finally, I would like to make you aware that there is a movement to recognize the Rights of the Great Salt Lake. This builds from other rights-based movements for waterways across the world--the Atrato River in Colombia, the Whanganui River in New Zealand, various waterways and watersheds in Colorado (recognized by non- binding resolution in the communities of Nederland, Grand Lake, and Ridgway), and the rights of Mar Menor in Spain. The DWQ may wish to consider how the rights of the Great Salt Lake, including mechanisms to give it a voice in governance, could benefit your efforts to protect and restore waterways. DWQ Response to comment 3B: Thank you for bringing these efforts to our attention. DWQ is deeply committed to protecting the Great Salt Lake ecosystem and all of Utah’s waterways. We look forward to seeing how these efforts progress. Shera Reems, EPA Region 8 Comment 4A: Assessments Specific to Rivers, Streams, and Canals, Table 11 How does DWQ communicate to the public the water bodies where early life stage presence has been confirmed? DWQ Response to comment 4A: DWQ develops tables that identify species present and associated seasons of early life stages for Utah Pollution Discharge Elimination System (UPDES) permits that desire that specificity when wasteloads are developed. These tables are developed on a case by case basis, and like any information that falls under our GRAMA guidance, can be provided to the public upon request. Comment 4B: Assessments Specific to Rivers, Streams, and Canals, Table 11 The last paragraph under notes for TDS should be deleted. It appears that this information should only be in the notes field for Sulfate. DWQ Response to comment 4B: DWQ appreciates you bringing this to our attention. The paragraph referenced in Table 11 in the TDS notes has been removed from the document. Comment 4C: High Frequency Assessments for Dissolved Oxygen (DO) In response to EPA’s informal question about the rationale for applying the 10% allowable exceedance frequency to the 7-day average and 30-day average DO criteria to high frequency DO data, UDWQ staff reminded EPA about the following language in R317-2-7: “For water quality assessment purposes, up to 10 percent of the representative samples may exceed the minimum or maximum criteria for dissolved oxygen, pH, E. coli, total dissolved solids, and temperature, including situations where such criteria have been adopted on a site-specific basis.” UDWQ emphasized that the 10% exceedance frequency (aka 10% rule) language is parameter specific. In reviewing the state’s assessment method for E. coli (pages 60 to 65), UDWQ only applies the 10% rule to the maximum E. coli criterion. To calculate the 30-day geometric mean, Scenario B of the assessment method suggests a minimum sample size of 5 grab samples. The methodology documents that a waterbody would be considered impaired if more than one geometric mean was exceeded. This method does not appear to require sufficient data to calculate whether 10% of the 30-day geometric means were exceeded. In contrast, for a more comprehensive dataset like high frequency DO, the state applies the 10% rule to the 7-day average and 30-day average and requires sufficient data to evaluate whether those averages are exceeded 10% of the time. Please explain this inconsistent application of the 10% rule cited in Section R317-2-7. EPA encourages UDWQ to consider revising the high frequency DO assessment method to align with the approach used to calculate the geometric mean for E. coli. Specifically, EPA recommends the state: a) define a less stringent minimum dataset for the calculation of the 7-day and 30-day average DO criterion (e.g., 3 to 5 days to calculate the 7-day average and 10 days to calculate the 30-day average), and b) place waterbodies on the 303(d) list with more than one exceedance of the 7-day or 30-day average. When assessing for DO, UDWQ should also consider the narrative criteria requirement for water quality conditions not to “…produce undesirable physiological responses in desirable resident fish, or other desirable aquatic life…” (R317-7.2). The 10% rule should not be implemented in a manner that obscures potentially harmful or lethal conditions to aquatic communities. DWQ Response to comment 4C: The difference in assessment methods between E. Coli and dissolved oxygen is derived from differences in water quality standards between the two parameters. The general 10% exceedance frequency language at R317-2-7.1 b. includes both dissolved oxygen and E. Coli. However, following EPA guidance, Utah’s E. Coli criteria includes an additional footnote (R317-2 Table 2.14.1, footnote 7) that specifically applies a 10% exceedance frequency for assessment to the two maximum criteria and excludes the 30-day geomean criteria: “For water quality assessment purposes, up to 10% of representative samples may exceed the 668 per 100 ml criterion (for 1C and 2B waters) and 409 per 100 ml (for 2A waters).” Only the general 10% exceedance frequency language is applied to dissolved oxygen criteria, and national guidance regarding appropriate exceedance frequencies for dissolved oxygen assessment is not currently available. Therefore, DWQ has not changed the exceedance frequency used for high frequency dissolved oxygen methods as recommended by the commenter. As described in the assessment methods, all waterbodies are subject to applicable narrative standard based water quality assessments such as biological assessments, observations of fish kills, and trophic state evaluations. Comment 4D: Nutrient Assessments Specific to Headwater Streams (Pages 40 to 41) During the 2022 Integrated Report cycle, EPA recommended DWQ consider including a column in the table, “Draft Integrated Report: 305(b) and 303(d)” that identifies headwater assessment units for which the numeric nutrient criteria apply. This information would also be helpful in the water quality data files that DWQ shares with the public. DWQ Response to comment 4D: All headwater watersheds are georeferenced. As suggested, DWQ will include this column in the referenced table. Comment 4E: Assessments Specific to Lakes, Reservoirs, and Ponds, Aquatic Life Use Support, Figure 9 (Page 49) In the second row of this Figure, should there be a “No” after the diamond “>10% of water column exceed criterion?” DWQ Response to comment 4E: Thank you for your comment. DWQ has updated the diagram in Figure 9 so that it is properly labeled. Comment 4F: Temperature and Dissolved Oxygen: Stratified Lakes and Reservoirs, Figure 12 (Page 52) Based on the information in the Figure, it appears that both a Tier I Not Supporting and Tier I Fully Supporting proceed to a Tier II Assessment. Is this correct? DWQ Response to comment 4F: The commenter is correct. The Tier II assessment process is independently applied to all lakes regardless of the results of the Tier I assessment methods. Comment 4G: Great Salt Lake (Pages 56 to 57) Previously, UDWQ indicated that the Great Salt Lake Water Quality Strategy components on Aquatic Life Numeric Criteria for Priority Pollutants and Strategic Monitoring and Research were in the process of being updated. Does UDWQ have an updated timeline for the completion of these components? DWQ Response to comment 4G: Updating the Great Salt Lake Water Quality Strategy and its core components is ongoing with a targeted completion date in mid-2024. Comment 4H: Harmful Algal Blooms (Pages 66 to 67) EPA appreciates DWQ’s work in assessing for Harmful Algal Blooms (HABs) and on updating the assessment method to rely on EPA’s recommended criteria for microcystin and cylindrospermopsin. Please clarify the following: Does UDWQ intend to apply these methods to benthic blooms similar to those observed in Zion National Park? DWQ Response to comment 4H: Thank you for asking for clarification. This assessment method will not be applied to any benthic harmful algal blooms affecting recreational beneficial use at this time. DWQ will be evaluating how to best incorporate appropriate assessment methodology for benthic blooms in the future. Comment 4I: Harmful Algal Blooms (Pages 66 to 67) Would UDWQ list waters as impaired for HABs if the waterbody exceeds UDWQ’s anatoxin-a warning threshold? DWQ Response to comment 4I: Until more information is available on the toxicity of anatoxin-a, DWQ chooses to withhold setting a specific cyanotoxin threshold for anatoxin-a in directly determining beneficial use support. DWQ looks forward to EPA recommending similar thresholds for other common cyanotoxins (including anatoxin-a) in the future. Anatoxin-a concentrations are, however, considered indirectly in beneficial use assessment. The second independent indicator of beneficial use support is waterbody recreational access or use limitations. Recreational advisories which may also list a waterbody as impaired, are generally issued by a health department when concentrations of anatoxin-a are greater than 15 ug/L. Ellen Bailey, DWQ Comment 5A: Harmful Algal Blooms There is a typo referring to table 16 in the HAB assessment. In the text it refers to table 15. DWQ Response to comment 5A: Thank you for pointing out these typos. DWQ has updated all the table references in the Harmful Algal Bloom section to the correct table. Ashley A. Peck, Wasatch Front Water Quality Council Comment 6A: Harmful Algal Blooms The Council has significant concerns with this approach because the HAB Guidance allows for the use of cyanobacteria cell density – on its own – to inform public health advisory decisions. This means that an impairment decision could also be based solely on two health advisories having been issued for the water body based on localized cell density sampling that is not representative of the water body as a whole – and notwithstanding whether cyanotoxin concentrations were above recreational guidelines. As EPA has recognized, cell density is not a reliable advisory trigger and is more stringent than the federal approach, in violation of Utah Code Section 19-5-105. Moreover, use of cell density-triggered health advisories as the basis for impairment decisions would impart a wholly subjective standard that likewise violates Utah Code Section 19-5-105. Under the HAB Guidance, cyanobacterial cell density greater than 100,000 cells/mL on its own could result in a “Warning Advisory” for the waterbody in question. However, relying on cell density is contrary to EPA guidance, which focuses exclusively on concentrations of microcystin and cylindrospermopsin to guide recreational health advisories. Indeed, EPA expressly declined to recommend issuing public health advisories based on cell counts, concluding that “available data are insufficient to develop quantitative recreational values” and that additional research is needed given the inconsistency in epidemiological studies. In other words, allowing cell counts to trigger warning advisories makes the HAB Guidance more stringent than its federal counterpart. This runs afoul of Utah Code Section 19-5-105, under which state standards developed in administering a program under the federal Clean Water Act can be no more stringent than federal standards addressing the same circumstances unless the Water Quality Board makes a written finding, after public comment and hearing, that the corresponding federal standard is not adequate to protect public health and the environment. Here, the Board has made no such finding. Because the inclusion of cell counts makes the HAB Guidance more stringent than its federal counterpart, DWQ should not tie impairment decisions to health advisories issued under the Guidance based on cell count. Instead, the HAB section of the Draft Assessment Methods should focus on whether microcystin and cylindrospermopsin concentrations have exceeded applicable thresholds. This will allow the final Assessment Methods to avoid being more stringent than, and conflicting with, federal standards. To achieve this, the Council requests that DWQ remove mention of warning advisories, danger advisories, and closures for recreational use from the HAB section of the Draft Assessment Methods or at minimum make both health advisories and cyanobacteria concentration together a trigger for impairment. Beneficial Use Supported The beneficial use is fully supported if, over the period of record: Cyanotoxin concentrations have not been identified above recreational use thresholds (Table 15), AND a Warning Advisory, Danger Advisory, or closure has not been issued for recreational access to a waterbody. Beneficial Use Not Supported The beneficial use is not supported if, in representative samples for recreational uses, in two or more years in the period of record: Cyanotoxin concentrations above recreational guidelines (Table 15) have been reported in more than three 10- day assessment periods in a recreational season, OR a Warning Advisory, Danger Advisory, or closure has been issued for recreational access to a waterbody for two or more 2-week periods in a recreational season. Insufficient Data and Information with Exceedances (IR Category 3) The waterbody will be placed in the insufficient data category if: It does not meet either of the Beneficial Use Not Supported criteria (above), but cyanotoxin concentrations exceeded recreational use thresholds (Table 15) in three or fewer 10-day assessment periods in a recreation season, OR a Warning Advisory, Danger Advisory, or closure has been issued for recreational use for less than two 2-week periods. These waterbodies will be prioritized for further sampling and evaluation. DWQ Response to comment 6A: Utah Code Section 19-5-105 prohibits the Water Quality Board from making rules that are more stringent than the corresponding federal regulations. The methodology for conducting beneficial use assessments isn’t a rule promulgated by the Water Quality Board. Similarly, the EPA guidance referenced by the commenter is not codified in federal regulation. As such, the inclusion of consideration of health advisories in the methodology for conducting beneficial use assessments is neither more nor less stringent than the federal Clean Water Act. Rather, health advisories simply provide an additional line of evidence that is independent from cyanotoxin benchmarks. DWQ strives to consider all readily available and relevant data in the assessment process. Formal waterbody assessments are not limited to numeric criteria as presumed by the commenter. Health advisories provide an opportunity to incorporate local risk assessment expertise into HAB assessments. Recreational use restrictions provide a direct indicator of whether recreational uses are supported in a waterbody. DWQ works collaboratively with local health departments and stakeholders through our Water Quality Health Advisory Panel to ensure that local health departments have the appropriate resources, scientific background, and technical support to make accurate decisions about health advisories. All assessment decisions are subject to a secondary review and public comments. Final assessment decisions consider the weight of evidence of quantitative data, the quality and robustness of available data, waterbody specific information and expertise, and public comment. Assessment decisions based on health advisory information can be modified in secondary review or following public comment if DWQ finds that the underlying data were inaccurate or if the weight of evidence of other indicators or other waterbody specific information demonstrated that to be appropriate. However, these decisions must be made on a case-by-case basis, carefully considering available information for a specific waterbody. No changes were made in response to this comment. David Richards, OreoHelix Ecological Comment 7A: Biological Assessments, Figure 7 [p. 2] Figure 7 on page 45 has been in the UDWQ IR methods for almost a decade. Its caption states that it is a hypothetical example of O/E, but it is delineated into Desert and Mountain ecoregions. This does not support the description of how the RIVPACS O/E model is used by UDWQ that states that the model is based on fifteen predictor variables which produce many more mostly watershed based expected reference taxa sites throughout the state than just two regions, Desert and Mountain. Figure 7 is obviously outdated and its continued use to illustrate the wonders of the RIVPACS O/E model as a sole metric for assessing biocriteria reaffirms my conclusion that UDWQ has put little effort into improving its understanding, assessment, and management of Utah’s rivers and streams using benthic macroinvertebrates. As a result, water quality of Utah’s cherished rivers and streams continues to be jeopardized. …[p. 6] Because this figure continues to be included in IR reports a naïve reader would conclude that UDWQ delineates all of Utah’s rivers and streams into only two regions, Desert and Mountain. Again, as I illustrated in Table 2 and discussed E for all mountain streams or all Desert streams would be a constant in this case E = 10 for desert streams, E = 30 for mountain streams. Multiply the denominator in O/E by its constant and all that is left is O, observed number of taxa i.e., Taxa Richness. DWQ Response to comment 7A: As stated directly in the caption, Figure 7 is a hypothetical example. The intent is to illustrate that O/E has the same meaning, even though Utah streams vary naturally in local richness. O/E compares the taxa predicted to occur at a stream in the absence of human disturbance against those taxa that were observed at the location. The figure simply indicates that O/E can generate similar scores among streams that naturally differ in biological condition. E is not a constant and contains site-specific information. The provided table and associated discussion reflects a misunderstanding of how O/E, particularly E, is calculated. RIVPACS model predictions are both site-specific and taxa-specific. Of course one can always multiply a fraction by its numerator to obtain its denominator, but doing so in this case eliminates many of the advantages of using O/E as opposed to using species richness. The calculations used to generate E are what allows these models to parse out natural changes in composition (including richness) from those associated with human-caused stressors. Briefly, E is calculated by first mathematically identifying groups of reference sites with similar taxonomic composition. For an assessed site, the geospatial predictor variables are used to quantify the probability that an assessed site would fall within each taxonomic group (Pg). The frequency with which each taxon occurs among reference sites within each group is then combined with the assessed site’s Pg across all groups to predict the probability of capturing (Pc) each individual taxon observed among all reference sites. E is the sum of those taxa with a 50% or greater chance of being observed at an assessed site based on that site’s specific geospatial watershed attributes. Moreover, O is not all taxa observed, but those observed taxa there were expected to be present in the absence of human disturbance (those predicted to occur), which is important because human-stress creates conditions that are advantageous for taxa that never would have otherwise occurred at a site. Richness is unable to make such distinctions. Details of these calculations are provided in the companion document cited in the methods or the hundreds of peer reviewed scientific papers that have been published on RIVPACS models, many of which have been provided to the commentator in previous Integrated Report cycles. Comment 7B: Biological Assessments, reliance on O/E as sole indicator of biological integrity [p. 2] The continued reliance and use of O/E metric by UDWQ as the sole measure of water quality ‘biological integrity’ is extremely troubling and reflects a poor understanding of biological integrity and the use of bioassessment methods as practiced throughout the world, including other neighboring states and counties, even Salt Lake County. No other water quality agency that I am familiar with relies on one metric, particularly with one such metric that has so many flaws as O/E. In fact, after the millions of taxpayer dollars spent on its development, it is no more informative than the Taxa Richness (number of taxa) metric that is easily calculated and used as the single most important bioassessment metric throughout the U.S…O/E is just one of many metrics. [p. 6] …I don’t agree that using a single taxon richness-based metric, RIVPACS O/E would constitute a robust index of biological integrity. It is only one metric that does not address anything other than richness and apparently does not do an adequate job of that (Richards 2016). There is also no reason to make a ‘robust IBI’ easily interpretable. Ecological interactions between dozens of organisms and their responses to human caused impairment are anything but easily interpretable. RIVPACS O/E models themselves are not easily interpretable. The data and algorithms used in these models are extremely difficult to obtain and often not available, thus not transparent. Other metrics used by other agencies, such as taxa richness, functional feeding group, etc. are very transparent and easily calculable. [p. 7]…Although O/E may have an intuitive biological meaning as stated by UDWQ, there are so many assumptions, generalizations, and errors associated with derivation of results that its accuracy in assessing loss of taxa and impairment is highly questionable. There are several other diversity metrics in use throughout the world that are much simpler to derive, provide insights into the causes of impairment, and are much easier to interpret than RIVPACS O/E (Table 1 for example and see Literature Cited). These metrics can easily substitute for O/E or at least supplement it. For example, richness and evenness are better indicators than O/E for several reasons, 1) they are not confounded with other models (e.g., PRISM, a costly and proprietary model that is not transparent except for those who can afford to pay for its use), 2) they are independently verifiable, and 3) they allow assessment of change at local-scale due to point source impacts. …[from results of study, p. 31]: There were strong effects of evenness and richness metrics on O/E scores, which apparently often affect biological assessments. Taxa richness obviously effects O/E scores because the O/E model is mostly based on this metric. Evenness directly effects taxa richness in a subsample and consequently directly and indirectly effects O/E scores. These effects need to be accounted for by water quality agencies before assigning an assessment score. DWQ Response to comment 7B: DWQ and independent experts reviewed this white paper and provided comments back to the commenter, including citations to numerous peer reviewed scientific papers that refute the claims. As discussed in previous IR cycles (see pp 70-72 in 2016 Integrated Report Response to Public Comments and pp 200-211 in Combined 2018 and 2020 Integrated Report), many of the opinions expressed in these comments (sometimes verbatim) are incorrect or incomplete. There are numerous peer reviewed scientific papers that have evaluated numerous aspects of O/E models, including: the relationship of O/E to richness and evenness, model complexity, their accuracy in identifying biological impairments, sensitivity to human-caused stressors, and many other topics. Many investigations have shown that O/E models are more accurate and often more sensitive to human caused stress than other biological indicators. As a result, RIVPACS continue to be used by numerous states and other countries around the world. This includes USEPA who uses these models in their national assessment programs. Other scientifically supported biological assessment tools exist, but this does not mean that O/E models are not a scientifically defensible method for identifying biologically degraded streams. Comment 7C: Biological Assessments, definition of biological integrity [p. 5] There is an urgent need to understand Clean Water Act biological integrity. Let me present one of the most widely used definitions of biological integrity, as defined by one of the leading experts, James Karr and colleagues. “Biological integrity refers to the capacity to support and maintain a balanced, integrated, adaptive biological system having the full range of elements (genes, species, assemblages) and processes (mutation, demography, biotic interactions, nutrient and energy dynamics, and metapopulation processes) expected in the natural habitat” … (Angermeier and Karr 1994, Karr and Dudley 1981, Karr et al. 1986). “Integrity implies an unimpaired condition or the quality or state of being complete or undivided; it implies correspondence with some original condition. Health, on the other hand, implies a flourishing condition, well- being, vitality, or prosperity”. “An ecosystem is healthy when it performs all its vital functions normally and properly; a healthy ecosystem is resilient, able to recover from many stresses; a healthy ecosystem requires minimal outside care” (Karr 1996). I have heard UDWQ staff try to define biological integrity at several meetings, and they consistently offer the “Readers Digest” condensed version of the above definitions in what I can only interpret as an excuse not to fully engage in the complexities of biological integrity and subsequently not fully protecting Utah’s water quality. DWQ Response to comment 7C: DWQ scientists understand Clean Water Act biological integrity and are familiar with these papers, but the information is appreciated. DWQ lacks sufficient information to respond to the comment regarding presentations at public meetings, but DWQ does sometimes simply present complex topics when presenting to the general public. Comment 7D: Biological Assessments, O/E Reference Sites [p. 5] UDWQ also claims that O/E is based on similar reference sites derived from fifteen predictor variables. If this is the case, then the expected number of taxa used in the metric becomes irrelevant…Derivation of expected number of taxa, E is problematic and filled with uncertainty that makes its use highly questionable. DWQ Response to comment 7D: Comments related to reference sites and model building were also addressed in previous IR cycles (see pp 70- 72 in 2016 Integrated Report Response to Public Comments and pp 200-211 in Combined 2018 and 2020 Integrated Report) along with peer reviewed scientific literature citations in the methods and responses that provides the background on RIVPACS models. In short, the models aren’t built with similar reference sites, but with a diversity of sites within the mountain and xeric west to capture natural variability. Comment 7E: Biological Assessments, loss of predicted taxa [p. 7] As I have emphasized to UDWQ on numerous occasions, RIVPACS O/E models do not quantify loss of predicted taxa. In the case of UDWQ assessments, O/E quantifies only those taxa that were identified from a single (N = 1) composite sample collected from several types of habitats (including riffles and runs) that can exhibit much variability between the macroinvertebrate assemblages. Samples were also identified in the laboratory using a subsample (typically 600 organisms, with large and rare counts). O/E simply quantifies what was observed in a sample, nothing more. Taxa not identified may have or may not have been lost from the waterbody they just weren’t counted because other taxa dominated the sample. UDWQ can only conclude that they simply weren’t observed, not lost. [p. 33]…Many RIVPAC O/E users continue to insist that a reduction in O/E scores reflects the extent to which taxa have become locally extinct due to human activities (UDWQ Integrate Report 2016). This is clearly not the case. The analyses included in this report highlight the fact that subsampling and evenness have significant effects on the number of taxa observed, especially the more uneven a sample and subsample. Taxa weren’t lost; they just weren’t found. They may not have even decreased in abundance. It is possible that other taxa could have disproportionally increased in abundance for whatever reason and that the ‘lost’ taxa simply weren’t counted. To continue to assume that native taxa have become locally extinct because O/E scores have decreased reflects a gross misinterpretation of RIVPACS O/E models. DWQ Response to comment 7E: Many of these comments were also addressed in previous IR cycles (see pp 70-72 in 2016 Integrated Report Response to Public Comments and pp 200-211 in Combined 2018 and 2020 Integrated Report). It is true that O/E does not directly measure the loss of taxa, but it does provide a quantitative site-specific estimate of the relative extent to which species loss has occurred among streams. As previously mentioned, the effect of sample error has been extensively evaluated in peer reviewed primary literature. Sampling error was calculated during model creation and these errors were used to create impairment thresholds. This O/E model has successfully identified biologically degraded streams, which is its primary function in the IR. It has also successfully been able to document improved biological conditions following stream restoration. Comment 7F: Biological Assessments, probability of capture >50% [p. 7] Again, as I have discussed on numerous occasions, probability of captures (Pc’s) >50% preclude those very macroinvertebrate taxa that constitute biological integrity in a water body (see definitions of biological integrity provided earlier in this response letter). As an example, waters in the Bonneville Basin and in some other parts of UT have unique mollusk assemblages found nowhere else in the world. Most of Utah’s mollusks, including native mussels, clams, and non pulmonate snails do not occur in UT waters at Pc rates > 50%. By relying on RIVPACS O/E > 50% Pc, UDWQ failed to protect the unique mollusk assemblages in UT and apparently was unaware of their declines during the time period when continued molluscan viability may have been protected/ensured. This is a tragic and unjustifiable loss of Utah’s unique natural heritage. Reliance on a single metric with > 50% Pc to assess biological integrity also likely is not protecting other rare and uncommon macroinvertebrates (< 50% Pc) that are again by definition, biological integrity. Calculating ‘E’ using a probability of capture (Pc) of >50% is extremely problematic and results in a poor assessment of biological integrity. Taxa with Pcs < 50% are likely the most sensitive taxa and the very taxa that respond to impairment more that those with Pc > 50%. The statement that “Using a Pc limit set at greater than 50% typically results in models that are more sensitive and precise, which results in a better ability to detect biological stress” is based on two relatively limited studies that evaluated precision using their own methods, i.e., circular reasoning and these were hardly typical. UDWQ is setting a precedent by using Pc > 50% based on results that are not solidly supported in the literature and not established scientific fact but based on a vague ill-defined term in the two studies, ‘sensitivity’. It appears that UDWQ is more interested in the continued reliance on a single metric (O/E) that had good statistical properties (e.g., more sensitive, and precise) than incorporating other metrics or using a < 50% Pc that may prevent loss of rare, uncommon, and unique taxa and provide greater insights into the types of impairments that Utah waterbodies experience. O/E models may be able to detect large levels of biological stress, but not biological integrity. …[p. 32] RIVPACS O/E models include a ‘probability of capture’ (Pc) component. Pc is the probability that a taxon occurs at a reference site and is used in the development of the “E” expected taxa list. To reduce ‘noise’ in results and to ease interpretation, many users, including UDWQ, use a PC > 50%. That is, the probability of a taxon occurring at a site is estimated to be greater than 50%. The decision to use a Pc > 50% has very strong negative implications for assessing the biological integrity of a river or stream in UT. Many ecologists agree that uncommon and rare taxa should be included in ecological assessments and by including these taxa detection of impacts is improved (Turak and Koop 2003; Nijboer and Schmidt-Kloiber 2004). It is also widely recognized that rare taxa are the first to become extinct due to human disturbance (Leitao 2016). Uncommon and rare taxa have also been shown to disproportionally contribute to ecosystem function and integrity (Leitao 2016). For example, native bivalves are extremely important for maintaining water quality via their filter feeding activity and of much concern for developing NH3 criteria. However, bivalves do not occur in >50% of Utah’s reference sites and unionids are likely on the brink of extinction in UT (Richards 2016b). A PC > 50% may easily overlook many, many, taxa that are unique to Utah’s rivers and streams including threatened and endangered species, important ecosystems providers, or simply an unknown number of taxa that occur in < 50% of reference streams. These taxa are the true measure of biological integrity and without which will result in a homogenous, biodiversity -limited condition lacking integrity. These taxa are also the most likely to be most sensitive to impacts because their niche breadth is much narrower that taxa that have Pcs > 50%. There is a well-known saying in ecology; ‘rare is common, and common is rare’ (Pimm et al. 2014). Modifications to RIVPACS O/E models have allowed researchers and managers in England to monitor rare species and to flag Red Data Book threatened species (http://www.ceh.ac.uk/services/rivpacs-reference-database), however they use much lower Pcs. Utah should consider the same. DWQ Response to comment 7F: All of these comments were made, in many cases verbatim, in previous IR cycles (see pp 70-72 in 2016 Integrated Report Response to Public Comments and pp 200-211 in Combined 2018 and 2020 Integrated Report) and DWQ created detailed responses to them. We also sent the comments and responses to other experts in biological assessments to ensure that our responses were valid. They were and remain so. The commenter is encouraged to reread those responses and the peer reviewed scientific literature cited in the responses. DWQ evaluated a Pc of 0 and 0.5 when Utah’s models were initially created. The Pc >0.5 model was more accurate and sensitive. More sensitive models, by definition, are better at identifying biologically impaired sites, which is important because that is the purpose of using the model in the IR. As we previously noted, this is hardly a precedent. There have been a number of studies supporting this. O/E is not biological integrity but an important aspect of it. Protecting, maintaining and restoring biological integrity is the central goal of the Clean Water Act, but that does not mean that DWQ needs to measure all of the many complex and important aspects of it. Doing so on a statewide basis is simply not possible. Instead, Utah and all states use indicators of biological integrity to evaluate water quality objectives. All numeric criteria work like this and so does the O/E model. As the commenter correctly notes, completely measuring all aspects of biological integrity is simply too complicated to accurately measure, particularly on a statewide basis. Comment 7G: Biological Assessments, RIVPACS O/E precision and predictive ability [p. 8] The new O/E model in the draft is claimed to be a less precise predictive model than the previous used by UDWQ. A loss of precision in the updated model should be critically reevaluated. Was this updated model selected because in saves time and money? As far as I can tell, O/E does not address intermittent stream benthic invertebrate assemblages. It is well known by all lotic ecologists that intermittent streams behave differently than perennial streams and that the benthic invertebrate assemblages differ dramatically. I have assisted the State of Idaho and the State of Arizona in their development of bioassessments for intermittent streams. It behooves UDWQ to realize that intermittent streams are abundant in Utah and are increasing due to global climate change and that intermittent streams need to have a different bioassessment paradigm and suite of assessment metrics than perennial streams/rivers. DWQ Response to comment 7G: These comments were made, in many cases verbatim, in previous IR cycles (see pp 70-72 in 2016 Integrated Report Response to Public Comments and pp 200-211 in Combined 2018 and 2020 Integrated Report) and DWQ created detailed responses to them. As our previous response indicated, the new model was selected because it was more applicable to a more physically and geographically heterogeneous group of streams. In particular, DWQ was interested in incorporating larger rivers. Also, climate change can potentially cause systematic changes in macroinvertebrate composition, even among reference sites, so it is important to update the models periodically to account for these changes. DWQ has not created assessment methods for intermittent streams and agrees that such methods would be useful. Hopefully resources will be available to expand to intermittent streams in the future. Comment 7H: Biological Assessments, Figure 8 [p. 9] There is no obvious starting point on the tree. It has two diamonds on the same top level that suggest starting points. However, following the first diamond “Were 3 or more samples collected?” if the answer was yes, leads to a nonsense conclusion, “Beneficial use Not Supported”. UDWQ constantly relies on diagrams to illustrate its methods and rational for decision making and this diagram has been used by UDWQ for several iterations of IRs and IR Methods. DWQ Response to comment 7H: DWQ thanks you for your comment. Figure 8 has been adjusted to clarify the starting point of the diagram. Comment 7I: Biological Assessments, incorporation of 1st and 8th+ order streams and rivers [p. 9] All aquatic ecologists know that there is a big difference in macroinvertebrate assemblages in typical 1rst order vs. 2nd to 5th streams and between 8th plus rivers and 2nd to 5th order stream (please review the River Continuum Concept by Vannote et al.). DWQ Response to comment 7I: This comment and others relating to stream size was made in previous IR cycles (see pp 70-72 in 2016 Integrated Report Response to Public Comments and pp 200-211 in Combined 2018 and 2020 Integrated Report) and DWQ completed detailed responses to them. As the commenter suggests, all aquatic ecologists know of ecological changes that occur along a river continuum, those at DWQ included. This is one of the main advantages of O/E models over other biological assessment methods such as IBIs. O/E scores scale along a continuum of ecological conditions using a variety of site-specific geospatial stream characteristics, whereas IBIs assume that streams in large, predetermined bins should have similar characteristics. The commenter is encouraged to reread previous responses to comments related to stream heterogeneity in previous IR cycles for additional details. Comment 7J: Biological Assessments, taxonomic resolution [p. 9] A coarser taxonomic resolution results in a major loss of valuable information provided by individual taxa when 'rolled up' to higher taxonomic level. It also means that some unique or ecologically valuable taxa may be unaccounted for and lost from the AU without knowledge by UDWQ. For example: combining all species of caddisflies in the genus Rhyacophila at least 5 species or more could be lost without UDWQs knowledge. Or by combining all species of the mayfly genus Baetis, several of the more sensitive species may have been lost. UDWQ is well aware that taxonomic (phylogenetic) similarity has very little predictive power for sensitivity to different types of impairment (Richards 2016, UDWQ 2017). DWQ Response to comment 7J: These comments were made, verbatim, in previous IR cycles (see pp 70-72 in 2016 Integrated Report Response to Public Comments and pp 200-211 in Combined 2018 and 2020 Integrated Report) and DWQ created detailed responses to them. The commenter is encouraged to reread previous responses for additional details. In short, DWQ requests that all taxa be identified to the lowest possible taxonomic resolution, but this is not always possible. The taxonomic resolution reflects these practical constraints. Despite taxonomic resolution constraints, this model has been able to accurately identify biologically degraded streams throughout Utah, which is its primary function for IR purposes. DNA barcoding and similar techniques are helping address this issue and hopefully DWQ will be able to incorporate these data in future biological assessment tools. Using traditional taxonomy, using a nationally accredited lab and requesting that all individuals be identified to the lowest possible level of taxonomic resolution seems reasonable. Comment 7K: Biological Assessments, seasonality effects [p. 10] Seasonality also affects macroinvertebrate assemblages. Summer season has fewer taxa in larval stages that are needed for taxonomic identification and O/E derivation. Comparing summer collected vs. late autumn to early spring samples increases variability and thus precision and accuracy O/E results (e.g., summer samples likely will have fewer taxa and lower O). DWQ Response to comment 7K: DWQ is aware that the composition and abundance of macroinvertebrate assemblages varies seasonally. If the general pattern in this comment was true everywhere, this problem would be easier to address. Utah is a geographically diverse place and the periods of maximum abundance and diversity can vary considerably from region-to-region and year-to-year. This temporal variation undoubtedly contributes to declines in model precision and accuracy. DWQ has tried to account for this variation in the modeling process. Interestingly, all versions prior to the current model included ‘Day-of-Year’ as a predictor variable, but this variable was not a significant source of variation in compositional differences among reference sites for the current model. The use of PRISM predictor variables likely helps account for some of the systematic difference in temporal variation patterns (see also DWQ response to comment 7L). It is also possible that temporal variation is minimized by other model construction decisions (Pc > 0.5, higher level OTUs). If true, this would explain why these models are more accurate and more sensitive in identifying biologically degraded streams. Comment 7L: Biological Assessments, reliance on PRISM data [p. 10] As discussed in earlier comment letters; PRISM models are proprietary black box and as such are not independently verifiable and thus are scientifically invalid. The scientific method requires the possibility of independent validations. PRISM models are not reproducible or transparent, which as we all agree, is what we are striving for. PRISM models rely on historic data (e.g., most of the climate data metrics in Table 12). As an example, “Watershed maximum of mean 1961-1990 annual number of wet days’ was 28-year old past data. Conditions likely have changed substantially in 28 years. Clearly the past has absolutely nothing to do with the macroinvertebrates collected next year. Similarly, the average of multiple years has nothing to do with invertebrate assemblages that are mostly multivoltine or univoltine. Their lives are shaped only by the conditions in the years during which they lived… not over multiyear averages. Variables in Table 12 had nothing to do with environmental conditions during the time when the sampled invertebrates lived. This introduces an unmeasurable and significant error to every Pc calculated and prevents the use of field data, which would be site specific. It may have been useful in developing regional models… but it has no place in continued assessment/monitoring and should never be used as such. Only field measurements should be used when possible. PRISM data errors are also spatially derived mostly from misuse of regional models to monitor local scale changes. These models will complicate every O/E assessment conducted anywhere that there are natural gradients, introducing error in every local assessment. PRISM data often are not precise, and values can change substantially between small changes in elevation within a watershed and sometimes within a few hundred meters. In addition, PRISM values are model predicted values and subject to error. DWQ Response to comment 7L: These comments were made, verbatim, in previous IR cycles (see pp 70-72 in 2016 Integrated Report Response to Public Comments and pp 200-211 in Combined 2018 and 2020 Integrated Report) and DWQ created detailed responses. The commenter is encouraged to reread previous responses for additional details, because as noted in previous responses many of these assertions are incorrect or reflect a misunderstanding of how O/E models are constructed. PRISM data are not proprietary and are freely available. They have been independently tested and validated. They are used by a very large community of scientists across a wide range of disciplines and are continually updated and corrected. O/E models perform best when the predictor variables describe longer-term, generalized conditions. The predictors are site-specific, but ultimately we are trying to distinguish between different types (i.e, low elevations vs high elevation, mesic vs. xeric, high- vs low-gradient). Prism data provide excellent reach scale information that strongly correlates with the spatial heterogeneity of stream conditions. For any given stream, the past is the best predictor of what should be there; long-term data show that community composition is stable. In fact, if bioassessment programs had historical data for all streams, predictive models would be unnecessary. Climate change is causing systematic changes in the composition of macroinvertebrate assemblages, which is one reason DWQ periodically updates the models with new reference site data. DWQ is initiating a new round of reference site collections in 2023. Comment 7M: Biological Assessments, Implications of evenness on O/E Scores and UDWQ Bioassessments [from study, p. 32] UDWQ uses a mean O/E score of > 0.76 as ‘fully supporting’ and in general, a score of < 0.69 as ‘not supporting’ (UDWQ Integrated Report 2016). If the SEM standardized loadings (coefficients) for the total effects of evenness on O/E scores in Table 9 are reasonable, then that would suggest that a 0.07 decrease in O/E score from 0.76 (fully supporting) to 0.69 (not supporting) would only require a decrease in evenness of about 0.044 (0.037 to 0.053). As discussed in footnote 2, page …, taxa abundances in macroinvertebrate samples are rarely if ever even, and this relatively small change in evenness could easily trigger an assessment from ‘fully supporting’ to ‘not supporting’. DWQ Response to comment 7M: Thresholds are derived based on an understanding of model error (which is based on actual field measures) and the specific values represent an attempt to balance type I (false positive) and type II (false negative) errors. This is a common dilemma for any regulatory agency in general and perhaps more so with those using biological data. DWQ has stated in the chapter the cost-benefit of ensuring that type I and II errors are appropriately balanced and are not arbitrarily set. DWQ has been using O/E models for over a decade and they have proven to provide robust assessments of biological use support. Follow-up investigations at impaired sites have almost always revealed one or more human stressors and the index has also been responsive to improving conditions following stream restoration.