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Home My WebLink AboutDWQ-2024-008838Charge Questions Update and Next Steps Science Panel Meeting | September 4, 2024 Overarching Charge Questions 1.What was the historical condition of Utah Lake with respect to nutrients and ecology pre-settlement and along the historical timeline with consideration of trophic state shifts and significant transitions since settlement? 2.What is the current state of the lake with respect to nutrients and ecology? 3.What additional information is needed to define nutrient criteria that support existing beneficial uses? [addressed as part of strategic research plan] 4.Can the lake be improved given current management constraints? Charge Question Responses 1.Evidence Evaluation Focus: technical Detailed analysis of studies that inform the question (Utah Lake and related) Figures from cited studies 2.Synthesis Focus: plain-language, non-technical Overall response to the question Includes assessment of SP confidence in the response Overview of Subgroup Outcomes & Next Steps •April-May 2024: Subgroups met to discuss updates to interim charge question responses •SP subgroups discussed: Minor edits to evidence evaluation Additional citations of related studies Additional context for interpretations Recommendations for translating synthesis bullets into paragraph form Recommendations for level of confidence In a few cases, more substantive recommendations for deeper dives into existing and/or upcoming studies Since June SP Meeting… •Sediment and mass balance subgroups met •Ongoing discussions about sediment research, particularly: Role of sediments in nutrient retention and release Potential impact of nutrient load reductions in in-lake concentrations (equilibrium sediment conditions, recovery time, etc.) •Outstanding analyses Sediment discussions (this meeting!) Mass balance analysis Mechanistic watershed and lake model analysis Confidence Evaluation Confidence Evaluation •High confidence Direct evidence in Utah Lake Well-established methods Consistent behavior of Utah Lake compared to lakes in the literature If multiple studies/lines of evidence, findings were consistent •“Big picture” conclusions more often resulted in high confidence •Sometimes very specific items or interacting drivers resulted in lower confidence •Questions needing analysis from mass balance and/or mechanistic models were not assessed for confidence yet High Confidence Evaluations Topic Confidence statement Historical Historical dominance of benthic diatoms, shifting to planktonic Shift from more sensitive taxa to more pollution- tolerant taxa Historical Historical presence of macrophytes in bays and shallow areas Historical Major changes in the lake: shift from macrophyte- to phytoplankton-dominated state, introduction of carp, European settlement and subsequent population- associated changes, increasing nutrient concentrations Historical Increasing primary production, shift from diatoms to green algae to cyanobacteria High Confidence Evaluations Topic Confidence statement Macrophytes & Diatoms Increased water clarity is needed to re- establish macrophytes (though several factors involved) Macrophytes & Diatoms Fluctuating water levels negatively impact macrophyte reestablishment Macrophytes & Diatoms Wind and carp have negative impacts on macrophyte reestablishment Macrophytes & Diatoms Macrophytes have a positive impact on sediment stabilization Aquatic Life Carp removal relieve negative pressures on macrophyte reestablishment, nutrient recycling, and bioturbation High Confidence Evaluations Topic Confidence statement Sediments Calcite scavenging plays a large role in the Utah Lake phosphorus cycle Sediments Rates of sediment oxygen demand, higher in Provo Bay than main basin Sediments Seasonal thermal stratification is not a driver of anoxia, P release, and HAB formation (redox gradients may occur transiently) High Confidence Evaluations Topic Confidence statement HABs Spatial hotspots for HABs HABs Nutrient limitation of HABs is driven by both N and P, with variability in co-limitation, timing, seasonality, light limitation HABs Larger blooms are associated with lower lake levels, which could be associated with temperature, nutrient dilution, water clarity, water residence time, and/or sediment-water interactions (correlation established, causation not established) HABs Majority of light attenuation is caused by suspended sediment, with a minor but substantial part due to phytoplankton Medium Confidence Evaluations Topic Confidence statement Historical Geographic specificity of historical macrophyte cover outside of bays and shallow areas (limited paleo evidence) Macrophytes & Diatoms Macrophyte restoration efforts take time and can require a combination of active management activities (several interacting factors) Sediments Rates of sediment nutrient fluxes (different approaches, scaling over time and space) Aquatic Life Introduction of carp is associated in time with the transition to eutrophic conditions (difficult to parse carp vs. other anthropogenic impacts concurrently) Aquatic Life Contribution of carp to the nutrient budget of the lake (extrapolation of uncertainty) Aquatic Life Relative influence of carp vs. wind on sediment resuspension Aquatic Life Spawning and rearing habitat meets the needs of some species at some sites, but not others Outstanding Charge Questions •What are current sediment equilibrium P concentrations (EPC) throughout the lake? What effect will reducing inputs have on water column concentrations? If so, what is the expected lag time for lake recovery after nutrient inputs have been reduced? •What is the sediment oxygen demand of, and nutrient releases from, sediments in Utah Lake under current conditions? •Does lake stratification [weather patterns] play a result in anoxia and phosphorus release into the water column? Can this be tied to HAB formation? •What would be the current nutrient regime of Utah Lake assuming no nutrient inputs from human sources? This question may require the identification of primary sources of nutrients. •If the lake stays in a phytoplankton-dominated state, to what extent can the magnitude, frequency, and extent of harmful and nuisance algal blooms be reduced through nutrient reductions? Overview of Subgroup Outcomes & Next Steps Draft Response Document Preparation TT to compile all charge question responses into a master document SP to review charge question responses Additional Evidence When evidence comes in, incorporate findings into the charge Q responses Discuss with relevant subgroups Final Response Document At SP meeting, seek to approve charge question responses Potential discussion with Steering Committee Questions and Discussion Note: all information and data presented are considered draft, in-process material UTAH LAKE WATER QUALITY STUDY Mass Balance Subgroup Update September 4, 2024 1 •What are current sediment equilibrium P concentrations (EPC) throughout the lake? What effect will reducing inputs have on water column concentrations? If so, what is the expected lag time for lake recovery after nutrient inputs have been reduced? •What is the sediment oxygen demand of, and nutrient releases from, sediments in Utah Lake under current conditions? •What would be the current nutrient regime of Utah Lake assuming no nutrient inputs from human sources? This question may require the identification of primary sources of nutrients. •If the lake stays in a phytoplankton-dominated state, to what extent can the magnitude, frequency, and extent of harmful and nuisance algal blooms be reduced through nutrient reductions? Outstanding Charge Questions •Purpose: Review the mass balance model (and other lines of evidence) to discuss how the model inform responses to the charge questions. Mass Balance Subgroup Purpose Meeting #1 •Definition of “baseline” total phosphorus in Utah Lake •How to characterize uncertainty in the mass balance model •Difference between net internal loading and gross internal loading •What happens to the sigma value (i.e., the first order rate constant) if external phosphorus loading is reduced? Subgroup Discussion Points Meeting #2 •Review of Utah Lake nutrient cycling visualization and discussion of the difference between net loading, gross loading, and “pools” •Presentation from Dr. Steve Nelson and discussion about gross loading diffusion estimates –268 mT/year (pH=8) –421 mT/year (pH=6.5) Subgroup Discussion Points Meeting #3 •Follow-up discussion on baseline phosphorus concentrations and net internal loading •Estimated sediment phosphorus accrual rates Subgroup Discussion Points •Evidence and discussion points were compiled into a visual diagram. •Today’s agenda is focused on: –A discussion of the existing evidence and conceptual diagram –How the existing evidence informs the Science Panel response to the outstanding charge questions Today’s Discussion QUESTIONS? 8 Technical Support Update and Next Steps Science Panel Meeting | September 4, 2024 Note: all information and data presented are considered draft, in-process material •Provide the technical basis for the development of numeric nutrient criteria (NNC) to protect designated uses •Recreation •Aquatic Life •Others (Agriculture, Downstream) •Conduct analyses to support multiple lines of evidence in the NNC framework Purpose of the Technical Support Document Note: all information and data presented are considered draft, in-process material •Discussions of magnitude, duration, frequency, and extent •Assessment methodology and DWQ monitoring •Approaches in other states (e.g., Beaver Lake, AR) Summary of Criteria Subgroup Activities Note: all information and data presented are considered draft, in-process material Criteria Elements •Magnitude Identify from TSD lines of evidence: reference, stressor-response, literature Final magnitude will depend on most sensitive use, plus application of weight-of-evidence •Duration Subgroup has discussed single sample vs. seasonal value (geomean as preferred aggregation) This choice may depend on which use and endpoint(s) are the most sensitive •Frequency Allowable exceedance frequency hasn’t been discussed extensively •Extent Utah Lake has 2 Assessment Units: Provo Bay and Main Basin Discussions of single-site exceedances vs. whole-lake Note: all information and data presented are considered draft, in-process material Other State Magnitude/Frequency/Duration Components Note: all information and data presented are considered draft, in-process material •Evaluated statewide and site- specific standards •Most TP criteria have unspecified frequency and duration components In many cases, these may just be “buried” in footnotes, assessment methods, minimum data requirements, etc. In other cases, may be unofficially interpreted. •Mix of temporal aggregation, percentiles, and max values Scott and Haggard 2015: Beaver Lake, AR •Site-specific criterion was adopted for Beaver Lake 8 µg/L chlorophyll 1.1 m Secchi depth Growing season geometric mean Weight-of-evidence approach •Standard development did not include assessment methodology recommendation allowable violations not defined •Goal: hindcast compliance with regard to spatial and temporal variability Note: all information and data presented are considered draft, in-process material Conclusions for Beaver Lake & Applicability to Utah Lake •Recommendation of chlorophyll and Secchi depth criteria was made without consideration of assessment method Long-term average of 8 µg/L chlorophyll expected to be exceeded ~half the time Conclusion of the paper was to recommend exceedances >1/2 the assessment period (e.g., 3 of 5) •In Utah Lake, we can consider the assessment method proactively! Incorporate risk/probability of exceedance into the analysis to derive magnitude Statistically translate between single-day observations and seasonal conditions, if applicable Note: all information and data presented are considered draft, in-process material Buoy Locations •High-frequency data: DO pH Chl & phycocyanin fluorescence •4 locations: 4917365 4917390 4917715 4917450 •Likely want regular monitoring to cover these sites Note: all information and data presented are considered draft, in-process material Chlorophyll Spatial Coverage DWQ Monitoring: Implications for Assessment Procedure •Scott provided a summary of current DWQ monitoring activities Staff time and budget are not unlimited! Program is conducive to periodic (i.e., monthly) sampling to capture “typical” conditions HAB advisory program does sample opportunistically could also be used to inform •“Reality Check” on feasible budget allocations Monthly sampling May-October (n = 6) 6 open water sites 5 marina sites (reducing to 2) 4 buoy sites Note: all information and data presented are considered draft, in-process material State Criteria Context: Jake Vander Laan Note: all information and data presented are considered draft, in-process material WQ standards rulemaking process 1.Water quality standards workgroup 2.Permission from Utah Water Quality Board to commence rulemaking 3.Submit rule change package to OAR (includes financial analysis) 4.Proposed rule published in state bulletin, 120 days to complete 5.Public notice, comment period, and hearing. DWQ responds to all comments. 6.Recommend adoption to WQ board, board vote is required for adoption 7.Obtain Attorney General certification of compliance with Utah law for rule adoption 8.EPA review and approval Note: all information and data presented are considered draft, in-process material Duration and frequency: things to consider •Timescale of target responses (direct toxic effects vs. indirect effects) •Timescale of implementation actions Assessment Point source effluent limits Non-point source controls •Variability in nutrient concentrations, uncertainty in estimating means Accounted for with a combination of duration, frequency, and minimum data requirements Not to exceed, long duration Shorter duration, magnitude adjusted for an acceptable exceedance frequency •Future data requirements and resource limitations for implementation Note: all information and data presented are considered draft, in-process material Example: National Lakes •Section 3.3 Duration and Frequency, examples in appendices D & E •Criteria magnitudes derived through a series of stressor/response models for DO, zooplankton, cyanotoxins, chlorophyll a, and nutrients •Recommended duration: growing season average •Adjust magnitude to account for uncertainty in estimating means and generate any desired frequency (operation criteria) •Consider generating multiple thresholds with different management responses (e.g. indicator value triggers additional sampling to estimate a mean) Note: all information and data presented are considered draft, in-process material Example: Arizona •Title 18 Chaper 11 F. Nutrient criteria •Magnitudes: annual mean, annual 90th percentile, and single sample maximum •Durations: annual and instantaneous •For 90th percentile: Min 10 samples, 10 days apart, consecutive 12 month period Not more than 10 percent of the samples may exceed the 90th percentile criterion Note: all information and data presented are considered draft, in-process material Example: Wisconsin •NR 102.06 Phosphorus Criteria magnitudes specified by waterbody type or on site-specific basis •NR 102.07 Assessing phosphorus concentration Duration: 2-10 year growing season mean (lakes & reservoirs) Minimum sample sizes (at monthly for 3 months) and representative sampling (2 m depth, near deepest part of lake) defined in rule Use a confidence interval approach for assessment: NR 102.52(2)(b) –“For metrics expressed as a mean or percentile of a group of samples, the department may use the two- sided 80 percent confidence interval of the mean or percentile for assessment.” Frequency: Not to exceed Note: all information and data presented are considered draft, in-process material Next Steps: SP and DWQ Coordination Note: all information and data presented are considered draft, in-process material Next Steps •SP and DWQ to coordinate which aspects of criteria will be recommended by SP and which will be incorporated into the assessment methodology by DWQ “Typical” state approach is to specify magnitude and sometimes duration in the criteria, and the specifics are described in the assessment methodology Does DWQ have guidance on elements that are set in stone, or elements with a strong preference? Do SP members have prior experience with implementing criteria that can inform this effort? •Discussions of calculation procedures Translating between different durations: EPA national recommendation for operational criteria Other state examples: would any of these be useful to apply here? Note: all information and data presented are considered draft, in-process material Note: all information and data presented are considered draft, in-process material Magnitude Frequency Duration Extent Definition Concentration of target parameter (e.g., chlorophyll, TN, TP) Acceptable exceedance frequency that would result in attainment The time period over which the criteria are calculated (e.g., average over a season) The spatial extent over which the criteria are applied Details Magnitude depends on weight- of-evidence evaluation of most sensitive use Examples include: •Not-to-exceed •1 in x years •Percentile (e.g., 10%) Depending on the relevant use and endpoint, a single-day sample or seasonal value may be appropriate Greater spatial extent would inherently require a lower magnitude to protect uses Option A: Least SP guidance SP provides recommendation for a magnitude that is protective of the most sensitive designated use SP recommends that DWQ identifies an acceptable exceedance frequency SP recommends that DWQ identifies an appropriate duration in the assessment method SP recommends that DWQ determines an appropriate spatial extent in the assessment methods Option B: Moderate SP guidance SP provides recommendation for a magnitude that is protective of the most sensitive designated use SP recommends that criteria are either applied as a not-to- exceed standard or with an allowable exceedance SP recommends that magnitude is evaluated over x duration (e.g., single sample, seasonal geomean) SP recommends that spatial extent be evaluated on a sampling site or whole lake basis Option C: Most SP guidance SP provides recommendation for a magnitude that is protective of the most sensitive designated use SP recommends a specific exceedance frequency along with rationale SP recommends that magnitude is evaluated over x duration, along with requirements for minimum sampling frequency and minimum number of samples SP recommends the spatial extent to be evaluated, along with zones of interest, minimum sampling sites, and aggregation approach Potential Workflow Associated with Options A, B, and C 1.Review recommended and example criteria from elsewhere 2.Present and discuss the range of options and examples 3.Synthesize SP discussion/feedback on criteria options 4.Identify pros, cons, and dealbreakers on potential criteria 5.Weigh findings, recommend an option 6.Draft and propose criteria 7.Update draft criteria following feedback 8.Finalize proposed criteria and proceed with state rulemaking Note: all information and data presented are considered draft, in-process material Option A: •DWQ executes steps 1-6 •SP provides feedback on proposed approach •DWQ executes steps 7-8 Option C: •SP executes steps 1-6 •DWQ provides feedback on proposed approach •SP executes step 7 •DWQ executes step 8 Option B: •SP executes steps 1-5 •DWQ executes steps 6-8 Questions and Discussion Note: all information and data presented are considered draft, in-process material Weight of Evidence Approach Discussion Science Panel Meeting | September 5, 2024 Note: all information and data presented are considered draft, in-process material Lines of Evidence 1.Reference-based Results from paleolimnological studies Utah Lake Nutrient Model prediction/extrapolation of reference conditions 2.Stressor-response analysis Utah Lake Nutrient Model output Statistical models 3.Scientific literature Scientific studies of comparable/related lake ecosystems Support/supplement other lines of evidence Note: all information and data presented are considered draft, in-process material Reference: Paleolimnological Reconstruction •Lines of Evidence Diatom community Macrophytes: physical remains, eDNA, C:N, H index Anodonta and Gastropods: physical remains C, N, H index/ratios and isotopes Cyanobacteria: eDNA, phytopigments Charcoal Sediment P concentrations and speciation Metals Note: all information and data presented are considered draft, in-process material Reference: Paleolimnological Reconstruction •Quantitative vs. Qualitative? Many lines of evidence are directional rather than directly quantifiable Some lines of evidence support inferences about nutrient concentrations –Shift from meso-oligotrophic to eutrophic –Approximate doubling of P concentrations Paleo reference evidence can be used as supporting evidence for stressor-response Note: all information and data presented are considered draft, in-process material Reference-Based Analysis •Model-based prediction (coming soon!) Run watershed model under a “reference conditions” scenario watershed nutrient loading Watershed conditions then used as boundary conditions for the lake model Run lake model with new boundary conditions, then analyze in-lake nutrient concentrations quantitative estimation of historical nutrient concentrations Note: all information and data presented are considered draft, in-process material Stressor-Response Analysis: Empirical •Types of regressions: Linear Quantile Logistic Bayesian network •All models will generate thresholds (if significant) and estimates of variability •WoE could be applied based on risk management and uncertainty around the relationship Note: all information and data presented are considered draft, in-process material Stressor-Response Analysis: Mechanistic •EFDC-WASP will be run under different scenarios: Current Reference Reduced nutrients •Can treat each of these scenarios as a point along the stressor-response curve, then run S-R models: Chlorophyll ~ TN Chlorophyll ~ TP Can use chlorophyll targets generated by other models and/or the mechanistic model to identify TN and TP targets Note: all information and data presented are considered draft, in-process material Literature Analysis Note: all information and data presented are considered draft, in-process material Weight of Evidence •Most sensitive use will dictate nutrient targets •But, ranges of nutrients may be deemed protective of most sensitive use across lines of evidence how to combine into a recommendation? Note: all information and data presented are considered draft, in-process material Combining Lines of Evidence: Weight of Evidence If more than one line of evidence has sufficient weight, need to merge Note: all information and data presented are considered draft, in-process material Questions and Discussion Note: all information and data presented are considered draft, in-process material 1 Utah Lake Science Panel September 5, 2024 Weight-of-Evidence: Application for Transparent and Defensible Nutrient Criteria Development 1 The views expressed here are those of the authors and do not necessarily represent the views or the policies of the U.S. Environmental Protection Agency. Acknowledgments Jesse Miller Kate Schofield Caroline RidleySylvia Lee Doug Kaylor Sam Penry Thank you to •EPA Office of Water and Regional Nutrient Coordinators •Several anonymous State staff •Author Team •Contract support: TetraTech 2 Presentation Outline •Background •WoE and NNC: The Basics •Why and how to use weight-of- evidence methods in criteria development 1.Planning/problem formulation 2.Analysis* 3.Criteria derivation* •State examples 3 Background 4 5 Problem: Resources were not readily available for how to conduct weight-of-evidence (WoE) when developing numeric nutrient criteria (NNC), despite its value and recommendation by EPA. Action: Develop materials with definitions, best practices, and examples to show how WoE can be used to combine diverse evidence applicable to NNC development. Result: States, Tribes and Territories have additional tools that complement OW’s N-STEPS program and other technical guidance that enable (1) maximum use of all available evidence during the criteria development process and (2) decisions about which WoE methods to use given unique evidence, resource, and timeline constraints. Impact: States, Tribes and Territories further strengthen transparency and defensibility of NNC that protect designated uses. Background Final Report Available Now! https://www.epa.gov/water- research/application-weight-evidence- methods-transparent-and-defensible- numeric-nutrient •Downloadable report •Future home of additional implementation resources •Templates •Short videos 6 What Report DOES ✓Complements existing guidance and support for criteria development ✓Focuses on freshwater criteria, although approaches and methods can be used for estuarine criteria, in principle ✓Uses plain language ✓Provides lots of visual examples 7 What Report Is NOT × NOT prescriptive- methods are NOT requirements × NOT exhaustive- most useful methods in the context of numeric criteria that we know about; if a method does not appear, that doesn’t mean it’s not good or appropriate given the right circumstances × NOT deriving criteria in any of the examples 8 WoE and NNC: The Basics 9 Weight-of-evidence is a process in which evidence is assembled, evaluated, and integrated to make a technical inference in an assessment. Gather an unbiased base of information. •Conduct studies and analyze data to produce evidence; search, screen and extract evidence from published literature; solicit evidence from experts and stakeholders. Determine the influence each piece of evidence should have on overall conclusions. •Evaluate and score relevance, strength, and reliability of evidence; combine scores to determine weight. Combine individual pieces of weighted evidence to form lines of evidence and determine which hypothesis is supported and with how much confidence. •Integrate evidence to produce weight of the body of evidence; interpret the body of evidence; explain discrepancies and uncertainties. What is Weight-of-Evidence (WoE)? W e i g h Body ofEvide n c e Wei g h t Eviden c e Asse m b l e Evid e n c e 10 Weight-of-evidence is a process in which evidence is assembled, evaluated, and integrated to make a technical inference in an assessment. Gather an unbiased base of information. •Conduct studies and analyze data to produce evidence; search, screen and extract evidence from published literature; solicit evidence from experts and stakeholders. Determine the influence each piece of evidence should have on overall conclusions. •Evaluate and score relevance, strength, and reliability of evidence; combine scores to determine weight. Combine individual pieces of weighted evidence to form lines of evidence and determine which hypothesis is supported and with how much confidence. •Integrate evidence to produce weight of the body of evidence; interpret the body of evidence; explain discrepancies and uncertainties. What is Weight-of-Evidence (WoE)? W e i g h Body ofEvide n c e Wei g h t Eviden c e Asse m b l e Evid e n c e 11 Weight-of-evidence is a process in which evidence is assembled, evaluated, and integrated to make a technical inference in an assessment. Gather an unbiased base of information. •Conduct studies and analyze data to produce evidence; search, screen and extract evidence from published literature; solicit evidence from experts and stakeholders. Determine the influence each piece of evidence should have on overall conclusions. •Evaluate and score relevance, strength, and reliability of evidence; combine scores to determine weight. Combine individual pieces of weighted evidence to form lines of evidence and determine which hypothesis is supported and with how much confidence. •Integrate evidence to produce weight of the body of evidence; interpret the body of evidence; explain discrepancies and uncertainties. What is Weight-of-Evidence (WoE)? W e i g h Body ofEvide n c e Wei g h t Eviden c e Asse m b l e Evid e n c e 12 Weight-of-evidence is a process in which evidence is assembled, evaluated, and integrated to make a technical inference in an assessment. What is Weight-of-Evidence (WoE)? W e i g h Body ofEvide n c e Wei g h t Eviden c e Asse m b l e Evid e n c e 13 Core Principles Transparency Documentation Communication Definitions Evidence:Information that enables inferences regarding a condition, cause, prediction, or outcome; ≠ data 14 Modified from EFSA 2017 and Suter 2016 Qual. or Quant. information and analysis Line of evidence Body of evidence of evidence (taken from pub lit) of evidence (taken from pub lit) Piece of evidence (literature) Line of evidence Line of evidence Piece of evidence Piece of evidence Piece of evidence Raw data (i.e., primary data) This Work Supports … 15 Planning Problem Formulation Analysis Criteria Adoption Data Collection Criteria Derivation This Work Supports … 16 Planning Problem Formulation Analysis Criteria Adoption = Assemble Evidence = Weight Evidence = Weigh Body of Evidence Data Collection Criteria Derivation This Work Supports … 17 Planning Problem Formulation Analysis Criteria Adoption = Assemble Evidence = Weight Evidence = Weigh Body of Evidence Data Collection Criteria Derivation Another Way to Think About WoE 18 Each container is a piece or line of evidence. Containers that are on this scale are relevant evidence. The size of the container is the reliability of the evidence. Where it is placed on the scale reflects the strength of the evidence. When experts gather the containers, decide if they go on the scale, how big they are, where they are placed, and ultimately which way the scale tips, they are conducting the weight-of-evidence process. Salafsky et al 2019 Strongly supports (++) Strongly refutes (--) Weakly refutes (--) Mixed support (+/-) Weakly supports (+) -+ Why and how to use weight-of-evidence methods in criteria development 19 1.Planning/problem formulation 2.Analysis 3.Criteria derivation 20 Criteria Development Phase Basic WoE Framework Element Key Suggested PracticesIntended Outcomes PlanningCore principlePlanning is transparent, documented, and leverages collective expertise. Decision-makers and stakeholders understand and trust the criteria development process. Planning minimizes bias, is realistic, and meets stakeholder needs. Assemble, weight, weighWoE methods are used to group water bodies. When Criteria Derivation Phase is reached,candidate criteria for each water body grouping have acceptably low amounts of variation. Problem FormulationAssemble, weight, weighWoE methods are used to select endpoints. Endpoints are relevant to management goals,measurable, ecologically relevant, sensitive to nutrients, and important to stakeholders. 21 Planning and Problem Formulation Phases 1.Planning/problem formulation 2.Analysis 3.Criteria derivation 22 Take home: Unbiased assembly of evidence is a best practice to ensure NNC are based on transparent data and information of sufficient amount and quality. Analysis Phase: Assemble Evidence Asse m b l e Evid e n c e 23 Sources of evidence (1)Evidence generated from data you collect and analyze (2)Literature-based evidence (3)Syntheses and meta-analyses (4)Generalized knowledge of aquatic systems; expert or stakeholder knowledge Considerations for unbiased assembly Analysis Phase: Assemble Evidence (1)Evidence generated from data you collect and analyze •Difference between bias in data vs. bias in individual analyses vs. bias in assembling evidence base- minimize and acknowledge •Relative comfort when scale of evidence matches scale of inference (e.g., intra-state), but considering larger (and smaller!) datasets can strengthen evidence base and fill evidence gaps •Unexpected or surprising evidence should trigger critical examination, not necessarily exclusion at this stage Asse m b l e Evid e n c e 24 Considerations for unbiased assembly (continued) Analysis Phase: Assemble Evidence (2) Literature-based evidence and (3) Syntheses and meta-analyses •Implement a transparent search strategy that meets your needs o Do you need to be comprehensive? = Broad, extensive search o Do you want to be reasonably sure you have the most relevant literature? = Targeted search •Establish clear inclusion and exclusion rules (4) Generalized knowledge of aquatic systems; expert or stakeholder knowledge •Intentionally diverse panels or workgroups •Public calls for information Asse m b l e Evid e n c e 25 Take home: Weighting evidence by establishing, objectively evaluating, and documenting qualities of that evidence shows how much influence individual evidence will have on overall NNC conclusions. 1.Relevance- degree of correspondence between the evidence and the conditions, stressors, and endpoints to which it is applied (e.g., biological, chemical, environmental) 2.Strength- degree of differentiation from control, reference, or randomness (e.g., magnitude, association, number often reported as a statistic) 3.Reliability- inherent properties that increases confidence in the evidence (e.g., study design, sample size, transparency) Analysis Phase: Weight Evidence Wei g h t Eviden c e 26 Take home: Weighting evidence by establishing, objectively evaluating, and documenting qualities of that evidence shows how much influence individual evidence will have on overall NNC conclusions. 1.Relevance- degree of correspondence between the evidence and the conditions, stressors, and endpoints to which it is applied (e.g., biological, chemical, environmental) •How closely does the study/analysis coincide with abiotic conditions of waters for which NNC are being derived? •How closely do the nutrient stressors and biological endpoints used in the study/analysis align with those under consideration for NNC? Analysis Phase: Weight Evidence Wei g h t Eviden c e 27 28 Analysis Phase: Weight Evidence 2.Strength- degree of differentiation from control, reference, or randomness •Magnitude: Commonly expressed as the effect size, difference between means, or a ratio of means. •Direction: Sign of an effect (i.e., positive or negative). •Association: Commonly expressed as a correlation coefficient or slope. •Number: The number of elements within a piece of evidence (e.g., of symptoms or overt effects in a response or of steps in a causal pathway) that are reported to be observed or the number of occurrences. This should not be confused with a candidate criterion value. 3.Reliability- inherent properties that increases confidence in the evidence •Design and execution: Evidence generated with a good study design that is well performed is more reliable. •Abundance: Evidence from more numerous data is more reliable, because it reflects greater replication or resolution. •Minimized confounding: Evidence is more reliable when the sampling design or analysis controls extraneous correlates. •Corroboration: Using models, indicators, or symptoms that have been verified by many studies and are accepted technical practice can greatly increase reliability. 29 Analysis Phase: Weight Evidence Reliability Analysis Phase: Weight Evidence Modified from Mupepele et al 2016 High reliability Low reliability Critically deficient Modified from Bennett et al 2021 Wei g h t Eviden c e Studies without underlying data Individual expert opinion Mechanism-based reasoning Observational studies (Inferential) studies with statistical testing (Descriptive) studies without statistical testing or Multiple lines of weak evidence Studies with a reference/control Case-control Before-after control-impact or Multiple lines of moderate evidence Review Systematic review Conventional review 1 2 3 4 We a s l e y 2 0 0 9 Ma l f o y 1 9 8 8 Be l l a e t a l . 2 0 1 1 Gr a n g e r e t a l . 2 0 1 3 He r m e s e t a l . 2 0 1 4 Va d e r e t a l . 2 0 0 7 -1 Va d e r e t a l . 2 0 0 7 -2 Methods clarity Study timeframe/duration Uncertainty measurement Gradient definition Reporting bias Overall reliability Study Re l i a b i l i t y 30 Qualitative methods for weighting Analysis Phase: Weight Evidence •Relevance, strength, and reliability are assessed independently. •Weights are conceptual, scores are symbolic. •Determine how to judge quality BEFORE the decision-making process begins; tailor weights to state- specific question(s). Wei g h t Eviden c e 31 Evidence Table: Hypothetical Example 32 Piece of Evidence Relevance (Rv) Strength (St) Reliability (Rb) Overall Weight Result (1) TP- Diatom Index S-R curve: Analysis generated with State field data +++++++++Field data from streams inside state (Rv) shows Index changepoint at TP=x mg/L with narrow CI (St); large sample size and wide nutrient gradient included (Rb) (2) TP- Diatom Index S-R curve: Analysis generated with field data outside of State +++0 0 Field data from streams outside state but with good environmental similarity (Rv) shows Index changepoint at TP=y mg/L with wide CI (St); single season data only (Rb) (3) Meta-analysis of TP-Diatom richness relationship: Literature ++++++++Meta-analysis of stream studies across the US (Rv) show a negative correlation between nutrient and biological endpoint for TP= >z mg/L (St); methods are well documented and repeatable (Rb) (4) Mesocosm phosphorus dosing experiment: Literature +0+++Experiment conducted in realistic stream mesocosm (Rv) shows no statistical change (St) in diatom richness with increasing doses of phosphorus; good sample size, reported experimental and analysis methods would be repeatable (Rb) 1.Planning/problem formulation 2.Analysis 3.Criteria derivation 33 Take home: Methods for integrating evidence to derive criteria can range from simple to sophisticated; selected methods should be logical, informed by evidence availability and stakeholder needs, and communicated clearly. •Combine individual pieces or lines of evidence to determine which hypothesis is supported and with how much confidence (that is- which way does the scale tip?). 1.Integrate evidence 2.Interpret bodies of evidence 3.Explain ambiguities and discrepancies Derivation Phase: Weigh Body of Evidence W e i g h Body ofEvid e n c e 34 Derivation Phase: Weigh Body of Evidence 35 of 62 W e i g h Body ofEvid e n c eStressor-Response Reference Condition NNC from other States Mechanistic Modeling Shape = Source of evidence Color = Analysis approach Size = Weight Opt 1: By analysis approach Opt 2: By source Primary data analysis Literature S-R S-R Thresh Ref Cond Ref Cond Mech Mod S-R S-R Ref Cond Mech Mod Ref Cond Thresh S-R Thresh S-R Thresh Evidence Aggregation: Example 36 UDEQ 2019 W e i g h Body ofEvid e n c e •Once aggregated, evidence can be integrated in several ways. ➢ Select the weightiest line of evidence to determine criterion. 37 Derivation Phase: Weigh Body of Evidence W e i g h Body ofEvid e n c e Evidence Table: Hypothetical Example Piece of EvidenceOverall WeightCandidate criterion Explanation (1) TP-Diatom Index S-R curve:Analysis generated with State field data ++TP=x mg/L with narrow CI Primary data analysis that has resulted in weightiest evidence. (2) TP-Diatom Index S-R curve:Analysis generated with field data outside of State 0TP=y mg/L with wide CI Similar primary data analysis as in (1), but underlying data represent only a single season, so evidence has unacceptably low reliability. Working with neighboring state to include multiple seasons in future analyses. (3) Meta-analysis of TP- Diatom richness relationship: Literature ++TP=α mg/L Threshold identified, but endpoint is not sensitive to nutrient change at low TP concentrations, resulting in substantial uncertainty around candidate criterion. (4) Mesocosm phosphorus dosing experiment: Literature +TP=β-γ mg/L TP candidate criterion range identified from low and medium dosage, but not statistically different from high dosage concentration. β<x<γ. Conclusion ++TP=x mg/L (1) selected to inform final criterion value. (4) is not strong, but corroborates value derived from (1). 38 •Once aggregated, evidence can be integrated in several ways. ➢ Select the weightiest line of evidence to determine criterion. ➢ Merge lines of evidence. •This has generally been a successful approach in criteria development/adoption. •Describe characteristics of evidence base as a whole (number of lines, coherence, absence of bias, diversity). •Characterize criterion- Magnitude, duration, frequency. 39 Derivation Phase: Weigh Body of Evidence W e i g h Body ofEvid e n c e Derivation Phase: Weigh Body of Evidence If merging lines of evidence, deriving a numeric criterion can happen in several ways. •One-step – should be consistent in nutrient and endpoint ➢ Arithmetic mean, geometric mean, median •Two-step combined criteria – confirming biota should also be sensitive to nutrients •More sophisticated ➢ Species sensitivity distributions ➢ Cumulative distribution functions ➢ Models used in meta-analysis ➢ Bayesian hierarchical models ➢ Multi-criteria decision analysis 40 W e i g h Body ofEvid e n c e Dealing with challenges •Uncertainty- incomplete understanding of state or true value ➢Increase sample size by including additional high quality (i.e., reliable) data •Variability- inherent heterogeneity of data ➢Include co-variates, more finely subdivide unit of analysis (e.g., classification) •Ambiguity- evidence with no clear meaning or more than one possible meaning ➢Solicit external expert review ➢Acknowledge plausible interpretations and be transparent about which ultimately informs the decision •Discrepancy- inconsistency in the evidence base ➢Understand which are logical ➢Critical look at underlying reliability of evidence ➢Design follow up studies that target resolution of discrepancy 41 Derivation Phase: Weigh Body of Evidence W e i g h Body ofEvid e n c e Communication: Weigh Body of Evidence 42 UDEQ 2019 W e i g h Body ofEvid e n c e Communication: Weigh Body of Evidence 43 Heiskary et al 2013 W e i g h Body ofEvid e n c e Documentation Best Practices ✓ Begin at Planning Phase- Technical plan provides transparency and a benchmark for how you intend the process to go; when things change, you can specify how and why in relation to the plan. ✓ Should enable repeatability- Just like the Methods section of a journal article, good documentation should enable someone to repeat your WoE process. ✓ Checklists and templates- Can make recording and communicating the details of your process easy. 44 Examples of helping states in different situations 45 State “A” versus State “C” Profiles State Timetable Availability of Primary Data Capacity to Analyze Primary Data Availability of Published Literature Capacity to Conduct New Studies Potential lines of evidence Potential derivation method A Inland waters: <1 year High Not Limited Low/Medium High •Literature •Stressor-Response •Reference Mean C Lakes and streams: 3-5 years Medium Limited Medium/High Medium •Literature •Stressor-Response •Reference TBD 47 State “A” versus State “C” Profiles State Timetable Availability of Primary Data Capacity to Analyze Primary Data Availability of Published Literature Capacity to Conduct New Studies Potential lines of evidence Potential derivation method A Inland waters: <1 year High Not Limited Low/Medium High •Literature •Stressor-Response •Reference Mean Key points: •Being later in the process means WoE methods could be used to strengthen existing approaches (e.g., enhancing documentation). •The abundance of primary data and capacity to analyze it doesn’t mean you don’t need evidence from published literature,but it could mean literature plays a different role- as a point of comparison or aid in selection of most relevant approach, for instance. •Identifying data gaps during derivation can guide conduct of new studies. 47 State “A” versus State “C” Profiles State Timetable Availability of Primary Data Capacity to Analyze Primary Data Availability of Published Literature Capacity to Conduct New Studies Potential lines of evidence Potential derivation method C Lakes and streams: 3-5 years Medium Limited Medium/High Medium •Literature •Stressor-Response •Reference TBD Key points: •Being earlier in the process means WoE process can help structure criteria development from the beginning. •Constraints with primary data and an abundance of published literature indicates the latter could be a valuable source of evidence and worth fully developing. •Derivation method options can be discussed/prioritized, with flexibility built in to accommodate final nature of the evidence. 48 Concluding Thoughts Criteria Development Phase Basic WoE Framework Element Key Suggested PracticesIntended Outcomes AnalysisAssembleEvidence is assembled in an unbiased way. Conclusions reached in the Criteria Derivation Phase are objective and defensible because they are based on evidence that accurately and fairly represents what is known about nutrients and their effects in water bodies. WeightWeighting criteria are established ahead of time; relevance, strength, and reliability of evidence are assessed and documented. Each piece of evidence has influence on the conclusions in the Criteria Derivation Phase that appropriately corresponds to its objectively evaluated relevance, strength, and reliability. Core principle Processes for assembling and weighting evidence are documented and communicated clearly. Decision-makers and stakeholders understand the pieces of evidence that make up the body of evidence and how they influence conclusions in the Criteria Derivation Phase. 49 Concluding Thoughts Criteria Development Phase Basic WoE Framework Element Key Suggested PracticesIntended Outcomes Criteria DerivationWeighIf necessary, evidence is logically aggregated. Integration method is appropriate for the evidence. Derived criteria are sound and defensible, because the method to either (a) select the weightiest evidence or (b) merge multiple lines of sufficiently weighty evidence is technically appropriate and justified to protect the designated use. Core principleConclusions are clearly communicated. Decision-makers and stakeholders understand and trust the derived criteria. 50 Additional resources 51 Additional Resources •Forthcoming •Template for documenting WoE process •Fillable PDF •Short videos •Intro to WoE •Using online evidence repositories to gather unbiased literature-based evidence 52 References and Resources •Bennett, MG; Lee, SS; Schofield, KA; Ridley, CE; Washington, BJ; Gibbs, DA. 2021. Response of chlorophyll a to total nitrogen and total phosphorus concentrations in lotic ecosystems: A systematic review. Environ Evid 10: 23. •Heiskary, S., R. W. Bouchard, and H. Markus. 2013. Minnesota nutrient criteria development for rivers. Environmental Analysis and Outcomes, Minnesota Pollution Control Agency, St Paul, Minnesota. (Available from:http://www.pca.state.mn.us/) •Mupepele, A.-C., Walsh, J.C., Sutherland, W.J. and Dormann, C.F. 2016. An evidence assessment tool for ecosystem services and conservation studies. Ecol Appl, 26: 1295-1301.https://doi.org/10.1890/15-0595 •Ridley et al. EcoDIVER: Ecological Database of Interactive Visualizations and Evidence Records. Web tool. www.epa.gov/ecodiver •Salafsky, N.,Boshoven, J.,Burivalova, Z. et al. 2019.Defining and using evidence in conservation practice.Conservation Science and Practice,1, e27.https://doi.org/10.1111/csp2.27 •Smith, A.J., and Tran, C.P. 2011.A weight-of-evidence approach to define nutrient criteria protective of aquatic life in large rivers.J. N. Am. Benthol. Soc.29:875–891. doi:https://doi.org/10.1899/09-076.1 •UDEQ. 2019. Numeric nitrogen and phosphorus criteria: Utah headwater streams. Utah Division of Water Quality, Salt Lake City, UT. •US EPA. 2016. Weight of evidence in ecological assessment.U.S. Environmental Protection Agency, Washington, DC.: Risk Assessment Forum; Report no. EPA/100/R-16/001. •US EPA. 2021.Ambient Water Quality Criteria to Address Nutrient Pollution in Lakes and Reservoirs.Office of Water, U.S. Environmental Protection Agency,Washington, DC. Report no.EPA/822/R-21/005. 53 Thank you! ridley.caroline@epa.gov 54 Extra slides 55 Summary of Suggested Practices and Intended Outcomes Criteria Development Phase Basic WoE Framework Element Key Suggested PracticesIntended Outcomes PlanningCore principlePlanning is transparent, documented, and leverages collective expertise.Decision-makers and stakeholders understand and trust the criteria development process. Planning minimizes bias, is realistic, and meets stakeholder needs. Assemble, weight, weighWoE methods are used to group water bodies.When Criteria Derivation Phase is reached,candidate criteria for each water body grouping have acceptably low amounts of variation. Problem FormulationAssemble, weight, weighWoE methods are used to select endpoints.Endpoints are relevant to management goals,measurable, ecologically relevant, sensitive to nutrients, and important to stakeholders. AnalysisAssembleEvidence is assembled in an unbiased way.Conclusions reached in the Criteria Derivation Phase are objective and defensible because they are based on evidence that accurately and fairly represents what is known about nutrients and their effects in water bodies. WeightWeighting criteria are established ahead of time; relevance, strength, and reliability of evidence are assessed and documented. Each piece of evidence has influence on the conclusions in the Criteria Derivation Phase that appropriately corresponds to its objectively evaluated relevance, strength, and reliability. Core principle Processes for assembling and weighting evidence are documented and communicated clearly. Decision-makers and stakeholders understand the pieces of evidence that make up the body of evidence and how they influence conclusions in the Criteria Derivation Phase. Criteria DerivationWeighIf necessary, evidence is logically aggregated. Integration method is appropriate for the evidence. Derived criteria are sound and defensible, because the method to either (a) select the weightiest evidence or (b) merge multiple lines of sufficiently weighty evidence is technically appropriate and justified to protect the designated use. Core principleConclusions are clearly communicated.Decision-makers and stakeholders understand and trust the derived criteria. 56 1.Planning/problem formulation 2.Analysis 3.Criteria derivation 57 Planning Phase •Opportunity to craft a transparent plan for all other steps leading to criteria adoption •WoE Framework can help structure the plan and inform specific approaches that the technical team will use •Tailored to specific decision context of State/Tribe/Territory •Flexibility can be built in ➢ Collective expertise can be leveraged from a workgroup or individual with a review process 58 Take home: Activities undertaken during planning provide a transparent foundation for developing NNC; transparency is a core principle of WoE. Grouping water bodies during Planning is amenable to WoE because diverse evidence may need to be combined. W e i g h Bod y ofEvide n c e Wei g h t Evide n c e Asse m b l e Evid e n c e Basic WoE Framework Planning Document 59 A planning document can have text and figures describing: •How candidate endpoints will be selected •How water bodies will be classified •What evidence and analysis approaches (e.g., stressor-response, reference conditions, and literature) will be considered •Discussion of dealing with limitations and trade-offs Planning Document: Hypothetical Example 60 Criteria development process for streams Stream classification Streams definition Further classify streams by geology, watershed boundaries, and nutrient distributions Instream protection Reference distribution approach 1.ID reference populations for TN and TP 2.Compute reference distributions 3.Select percentile of reference distribution as TN, TP criteria Downstream protection 1.Lakes- ID empirical or mechanistic models to calculate TN and TP in streams which would be protective of downstream lakes 2.Estuaries- Approach TBD Adding some WoE details to a plan Problem Formulation Phase •Results in (1)assessment endpoints that adequately reflect management goals and the ecosystem they represent (2)conceptual models that describe key relationships between nutrients and assessment endpoints 61 •WoE process can be used WITHIN a phase of criteria development in addition to ACROSS phases Take home: Selecting endpoints during Problem Formulation is also a process to which WoE could be applied when diverse evidence needs to be combined. Conceptual models developed during problem formulation can help inform what evidence should be assembled for the Analysis Phase. Endpoint Selection: Two Examples 1.The body of evidence supports recently recommended endpoints for lake and reservoir WQC that are measurable, sensitive to nutrients, and nationally relevant to management goals. Evidence includes mechanism-based reasoning, literature, and existing stressor-response models (EPA 2021). 2.Lake managers from northeastern states are developing diatom-based endpoints that are sensitive to nutrients and regionally ecologically relevant. Evidence includes primary data analyses of diatom assemblage information, literature, and expert knowledge. 62 Number of quantitative stressor-response relationships between nutrients and chlorophyll-a, diatoms, and macroinvertebrates in streams and rivers Literature-based evidence Analysis Phase: Assemble Evidence Adapted from Bennett et al 2021EcoDIVER available now! Meta-analysis •Response of chlorophyll to TN and TP •Summarizes evidence from dozens of individual studies to show strength and direction of relationships Asse m b l e Evid e n c e 63 Integrating Evidence: Two Examples •Example of selecting weightiest evidence: U.S. EPA’s guidance and models for the development of nutrient criteria in lakes creates a path for developing a single relevant, strong, and reliable line of evidence that informs numeric criteria (U.S. EPA 2021). •Example of merging evidence: Based on biological changepoints and cluster analysis, a weighted mean was calculated to recommend TP criterion for large rivers in New York (Smith and Tran 2010). 64 UTAH LAKE WATER QUALITY STUDY Science Panel Update September 5, 2024 1 Major Tasks Completed Over the Past Year •Implementation of the Strategic Research Plan •Updates the charge question responses •Advancement toward developing Numeric Nutrient Criteria (NNC) recommendations Science Panel Major Tasks STRATEGIC RESEARCH PLAN UPDATE 3 Purpose •Identify major remaining knowledge and data gaps that are constraining the certainty and confidence with which the SP can respond to charge questions and recommend NNC •Recommend strategic research to fill those knowledge and data gaps Strategic Research Plan - Overview Studies Conducted •Sediment Nutrient Interactions Study •Carbon, Nitrogen, and Phosphorus Budget Study •Bioassay Study •Littoral Sediment Study •Phosphorus-Binding Study •Paleolimnology Study •TSSD Limnocorral Study* •Atmospheric Deposition Study* Strategic Research Plan – Study Overview Strategic Research Plan – Study Status Study Name Primary Investigator Purpose Status Sediment Nutrient Interaction Study Dr. Ramesh Goel, University of Utah Determine the importance of nutrient exchanges between the sediments and water column. 100% Complete Carbon, Nitrogen, and Phosphorus Budget Study Dr. Kateri Salk, Tetra Tech Determine the nutrient loads and amount of water entering and leaving Utah Lake annually. 100% Complete Bioassay Study Dr. Zach Aanderud, Brigham Young University Determine which nutrients are controlling algal growth and how it changes across the lake and throughout the year. 100% Complete Strategic Research Plan – Study Status Study Name Primary Investigator Purpose Status Littoral Sediment Study Dr. Erin Rivers, Utah State University Determine how the wetting and drying of sediments due to changing lake levels affect nutrient cycling. 100% Complete Phosphorus-Binding Study Dr. Josh LeMonte, Brigham Young University Determine how phosphorus molecules interact with other molecules, like calcite, in Utah Lake and how those interactions affect how much phosphorus is available for living organisms (e.g., algae and cyanobacteria) 100% Complete Paleolimnology Study Dr. Janice Brahney, Utah State University Determine the historical condition of Utah Lake and describe how water quality changed over time. 100% Complete Timpanogos Special Services District (TSSD) Limnocorral Studies •Research presented at the 2023 June Science Panel meetings •2022 and 2023 reports completed and distributed to Science Panel •Studies ongoing for 2024 Strategic Research Plan – Ongoing Studies •Aug 2022 to Feb 2023: A Science Panel subgroup met 20 times to discuss atmospheric deposition data. •Science Panel voted to accept the number; it was not an unanimous vote. Strategic Research Plan – Atmospheric Deposition Science Panel Majority Estimate (Metric Tons/Year) Science Panel Minority Estimate (Metric Tons/Year) Dissolved Inorganic Nitrogen 220 Range: 218 to 249 N/A Total Phosphorus 32 Range: 31-43 150 Range: 93-200 CHARGE QUESTION UPDATE 10 High-Level Charge Questions 1.What was the historical condition of Utah Lake with respect to nutrients and ecology pre-settlement and along the historical timeline with consideration of trophic state shifts and significant transitions since settlement? 2.What is the current state of the lake with respect to nutrients and ecology? 3.What additional information is needed to define nutrient criteria that support existing beneficial uses? [addressed as part of strategic research plan] 4.Can the lake be improved given current management constraints? High-Level Charge Questions Charge Question Process Overview •Aug-Oct 2021: Science Panel met in subgroups to develop interim charge question responses. •Jan 2022: Steering Committee and Science Panel jointly met to review and discuss the interim charge question responses. •Apr-May 2024: Science Panel met in subgroups to update the charge question responses using new available data from completed studies. •Ongoing: Science Panel continue to review responses with the goal of approving them in the near future. Outstanding Charge Questions •What are current sediment equilibrium P concentrations (EPC) throughout the lake? What effect will reducing inputs have on water column concentrations? If so, what is the expected lag time for lake recovery after nutrient inputs have been reduced? •What is the sediment oxygen demand of, and nutrient releases from, sediments in Utah Lake under current conditions? •What would be the current nutrient regime of Utah Lake assuming no nutrient inputs from human sources? This question may require the identification of primary sources of nutrients. •If the lake stays in a phytoplankton-dominated state, to what extent can the magnitude, frequency, and extent of harmful and nuisance algal blooms be reduced through nutrient reductions? Additional Evidence •Additional evidence that will be assessed to develop charge question responses: •Dr. Mike Brett’s Mass Balance Analysis •Dr. Steve Nelson’s Diffusion Estimates White Paper •Mechanistic watershed and lake model analysis NUMERIC NUTRIENT CRITERIA RECOMMENDATION DEVELOPMENT 16 Technical Support Document Purpose of the Technical Support Document •Provide the technical basis for the development of numeric nutrient criteria (NNC) to protect designated uses •Recreation •Aquatic Life •Others (Agriculture, Downstream) •Conduct analyses to support multiple lines of evidence in the NNC framework Technical Support Document Lines of Evidence 18 •Reference-based •Results from paleolimnological studies •Utah Lake Nutrient Model prediction/extrapolation of reference conditions •Stressor-response analysis •Utah Lake Nutrient Model output •Statistical models •Scientific literature •Scientific studies of comparable/related lake ecosystems •Support/supplement other lines of evidence Current focus of the Science Panel Science Panel Next Steps 19 Ongoing Work Continue to discuss the Stressor-Response statistical analyses Watershed/In-Lake Model Update •Watershed model is nearly completed. •In-lake model is currently being calibrated (expected in Nov/Dec). •Next step is to connect the watershed model to the lake model. QUESTIONS? 20 Intro to Implementation Planning Scott Daly Division of Water Quality (UDEQ) Project Milestone 2015 2018 Data gathering; process development Phase I Phase II: Criteria Development 2021 Nutrient Criteria Framework Strategic Research Develop Criteria Framework Implementation Plan Phase III: Implementation Planning Implementation 203020222025 Implementation Framework Framework Development Process •POTW considerations •Steering Committee considerations Implementation Framework Implementation Objectives •Effective strategies result in measurable improvements •Address all significant sources •Practical •Cost effective & feasible •Flexible & adaptive “…roadmap for negotiating, defining, and developing all elements of a stakeholder-supported process…” Implementation Framework 1. ULWQS Phase 2 2. Build Partnerships 3. Characterize Watershed 4. Management Strategies 5. Permitting Approach 6. Cost & Feasibility 7. Assemble Plan In-Lake Strategies •Carp and fisheries management •Macrophyte reestablishment •Nutrient recycling •Biological, chemical, and mechanical treatments 4. Nutrient Management Strategies Courtesy Utah Lake Authority Watershed Strategies •Nonpoint sources •Point sources •Stormwater •Atmospheric deposition Technical Support Contractor Technical Support Tasks & Deliverables Subtask Framework Element Name Framework Element # (Line #) Deliverable Task 1.1 Watershed Characterization 3 (lines 9-12)  Data compilation & gaps  Source ID & quantification  Critical source areas  Future growth scenario Task 1.2 Assess Potential Nutrient Management Strategies 4 (lines 15-20)  ID potential management practices  Evaluate effectiveness Task 1.3 Permit Implementation 5 (lines 21, 23)  NNC permitting approach Task 1.4 Cost and Feasibility 6 (line 26)  Cost & feasibility for selected alternatives Task 1.5 Assemble the Implementation Plan 7 (lines 27-33)  Draft & final water quality implementation plan Schedule & Milestones 6 Month Schedule Meeting Schedule Task Work Element ASAP – October Introduce Technical Support Team Task 1.1. Watershed characterization Data compilation & gaps, critical source areas, future growth and land use scenario November – December Task 1.1. Watershed characterization Critical source areas and growth scenario December – February Task 1.2. Assess management strategies BMP evaluation framework, identify optimal BMPs for each source Questions? Contact us Scott Daly Utah Lake Watershed Coordinator PHONE (385) 321-6501 EMAIL sdaly@utah.gov utahlake.deq.utah.gov