DWQ-2024-005209

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Utah Division of Water Quality Statement of Basis ADDENDUM Wasteload Analysis and Antidegradation Level I Review Date: June 19, 2024 Prepared by: Christopher L. Shope Standards and Technical Services
Facility: Parleys Water Treatment Facility
UPDES Permit No. UT-7PARWTF This addendum summarizes the wasteload analysis that was performed to determine water quality based effluent limits (WQBEL) for this discharge. Wasteload analyses are performed to
determine point source effluent limitations necessary to maintain designated beneficial uses by evaluating projected effects of discharge concentrations on in-stream water quality. The wasteload analysis also takes into account downstream designated uses (UAC R317-2-8). Projected concentrations are compared to numeric water quality standards to determine acceptability. The numeric criteria in this wasteload analysis may be modified by narrative
criteria and other conditions determined by staff of the Division of Water Quality. Discharge Outfall 001 discharges on the southwest side of the treatment facility into the retention basin described as Sherwood/s Pond, which flows into Parleys Creek.
The specific design flow details were not explicitly provided in the application. However, in discussions with the Permit Writer, the estimated average daily discharge is 0.0049 MGD. It was suggested that estimated maximum daily design flow rate would double the average daily discharge. Therefore, the presumptive maximum daily design flow rate is 0.0098 MGD.
Receiving Water Per UAC R317-2-13.5.a, the designated beneficial uses Parley's Creek and tributaries, from 1300 East in Salt Lake City to Mountain Dell Reservoir are: 1C,2B,3A.
• Class 1C - Protected for domestic purposes with prior treatment by treatment processes
as required by the Utah Division of Drinking Water
• Class 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
• Class 3A -- Protected for cold water species of game fish and other cold water aquatic
life, including the necessary aquatic organisms in their food chain.
Utah Division of Water Quality Wasteload Analysis
Parleys Water Treatment Facility, UPDES Permit No. UT-7PARWTF
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Flow Typically, the critical flow for the receiving water in a wasteload analysis is considered the lowest stream flow for seven consecutive days with a ten-year return frequency (7Q10). Daily
in-stream flow records were analyzed from USGS 10171600 PARLEYS CR @ SUICIDE ROCK NR SALT LAKE CITY, UT monitoring location to calculate the seasonal 7Q10 critical flow conditions. The period of record available was from 1963 through 1990. The calculated critical low flow values are listed in Table 1.
Table 1. Critical Low Flow USGS 10171600 PARLEYS CR @ SUICIDE ROCK NR SALT LAKE CITY UT
Season Critical Low Flow (cfs)
Summer (July-Sept) 1.59
Fall (Oct-Dec) 1.47
Winter (Jan-Mar) 1.45
Spring (Apr-June) 2.24
Receiving water quality was characterized using data from DWQ Monitoring Station DWQ 4992170 MOUNTAIN DELL CK @ U65 XING BL LIL DELL RES for the period 2014-2024. Total Maximum Daily Load (TMDL)
According to the Utah’s Final 2022 Integrated Report on Water Quality dated December 9, 2022, the receiving water for the discharge, “Parley's Creek and tributaries, from 1300 East in Salt Lake City to Mountain Dell Reservoir (Assessment Unit UT16020204-025_00)” was listed as “Not Supporting” for Dissolved Oxygen and Benthic Macroinvertebrates Bioassessments. A TMDL is needed, however, the priority is low.
Mixing Zone The maximum allowable mixing zone is 15 minutes of travel time for acute conditions, not to exceed 50% of stream width, and 2,500 feet for chronic conditions, per UAC R317-2-5. Water
quality standards must be met at the end of the mixing zone. Acute limits were calculated using
50% of the seasonal critical low flow. Parameters of Concern The potential parameters of concern identified for the discharge/receiving water were determined
in consultation with the UPDES Permit Writer, the Watershed Coordinator, the Utah Water Quality
Assessment Reports, and the industry SIC codes from https://www.osha.gov/data/sic-search. The potential parameters of concern for this facility include: total suspended solids (TSS), dissolved oxygen (DO), BOD5, COD, total organic carbon (TOC), fluorine, iron, and aluminum.
WET Limits
The percent of effluent in the receiving water in a fully mixed condition, and acute and chronic dilution in a not fully mixed condition are calculated in the WLA in order to generate WET limits. The LC50 (lethal concentration, 50%) percent effluent for acute toxicity and the IC25 (inhibition concentration, 25%) percent effluent for chronic toxicity, as determined by the WET
test, needs to be below the WET limits, as determined by the WLA. The WET limit for LC50 is
typically 100% effluent and does not need to be determined by the WLA. Table 2 provides the seasonal WET limits and the associated dilution ratio.
Utah Division of Water Quality Wasteload Analysis
Parleys Water Treatment Facility, UPDES Permit No. UT-7PARWTF
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Table 2: WET Limits for IC25
Season Percent Effluent Dilution Ratio
Summer 0.9 % 105.0
Fall 1.0 % 97.0
Winter 1.0 % 95.5
Spring 0.7 % 147.5
Wasteload Allocation Methods Effluent limits were determined for conservative constituents using a simple mass balance mixing analysis (UDWQ 2021). The mass balance analysis is summarized in the Wasteload Addendum.

The Utah Rivers Model was used to evaluate the DO sag and implications on nutrients and BOD. The analysis is summarized in the Wasteload Addendum. The water quality standard for chronic ammonia toxicity is dependent on temperature and pH,
and the water quality standard for acute ammonia toxicity is dependent on pH. The AMMTOX
Model developed by University of Colorado and adapted by Utah DWQ and EPA Region VIII was used to determine ammonia effluent limits (Lewis et al. 2002). The effluent limits for DO and BOD5 in order to meet minimum DO criteria in the receiving water
was evaluated using the Utah River Model.
Models and supporting documentation are available for review upon request. Antidegradation Level I Review
The objective of the Level I ADR is to ensure the protection of existing uses, defined as the
beneficial uses attained in the receiving water on or after November 28, 1975. No evidence is known that the existing uses deviate from the designated beneficial uses for the receiving water. Therefore, the beneficial uses will be protected if the discharge remains below the WQBELs presented in this Wasteload.
A Level II Antidegradation Review (ADR) is required for this facility. The proposed permit is a is a new permit that has not been previously authorized. Documents:
WLA Document: 240528-SLCDPW_Parleys_WTF_WLA_2024.docx Wasteload Analysis and Addendums: 240528-SLCDPW_Parleys_WTF_WLA_2024.xlsm
References: Tetra Tech Inc. 2004. TMDL Water Quality Study of the Virgin River Watershed. Utah Division of Water Quality.
Utah Division of Water Quality. 2022. Final 2022 Integrated Report on Water Quality. https://documents.deq.utah.gov/water-quality/monitoring-reporting/integrated-report/DWQ-2022-002386.pdf Utah Division of Water Quality. 2021. Utah Wasteload Analysis Procedures Version 2.0. https://documents.deq.utah.gov/water-quality/standards-technical-services/DWQ-2021-000684.pdf
Utah Division of Water Quality
Salt Lake City, Utah
WASTELOAD ANALYSIS [WLA]= not included in the WLA 5/28/2024
Addendum: Statement of Basis 4:00 PM
Facilities: SLCDPW Parleys Water Treatment Facility UPDES No:UT-7PARWTF
Discharging to:Parleys Creek - Jordan River - Great Salt Lake
I. Introduction
Wasteload analyses are performed to determine point source effluent limitations necessary to maintain designated
beneficial uses by evaluating projected effects of discharge concentrations on in-stream water quality. The
wasteload analysis also takes into account downstream designated uses [R317-2-8, UAC]. Projected concen-
trations are compared to numeric water quality standards to determine acceptability. The anti-degradation
policy and procedures are also considered. The primary in-stream parameters of concern may include metals
(as a function of hardness), total dissolved solids (TDS), total residual chlorine (TRC), un-ionized ammonia (as a
function of pH and temperature, measured and evaluated interms of total ammonia), and dissolved oxygen.
Mathematical water quality modeling is employed to determine stream quality response to point source discharges.
Models aid in the effort of anticipating stream quality at future effluent flows at critical environmental conditions
(e.g., low stream flow, high temperature, high pH, etc).
The numeric criteria in this wasteload analysis may always be modified by narrative criteria and other conditions
determined by staff of the Division of Water Quality.
II. Receiving Water and Stream Classification
Parleys Creek - Jordan River - Great Salt L 1C,2B,3A
Antidegradation Review:Level I review completed. Level II review is required.
III. Numeric Stream Standards for Protection of Aquatic Wildlife
Total Ammonia (TNH3)Varies as a function of Temperature and
pH Rebound. See Water Quality Standards
Chronic Total Residual Chlorine (TRC)0.011 mg/l (4 Day Average)
0.019 mg/l (1 Hour Average)
Chronic Dissolved Oxygen (DO) 6.5 mg/l (30 Day Average)
9.5 mg/l (7Day Average)
8.0 mg/l (1 Day Average)
Maximum Total Dissolved Solids N/A mg/l Background
Acute and Chronic Heavy Metals (Dissolved)
4 Day Average (Chronic) Standard 1 Hour Average (Acute) Standard
Parameter Concentration Load*Concentration Load*
Aluminum 87.00 ug/l**0.007 lbs/day 750.00 ug/l 0.061 lbs/day
Arsenic 150.00 ug/l 0.012 lbs/day 340.00 ug/l 0.028 lbs/day
Cadmium 1.80 ug/l 0.000 lbs/day 5.21 ug/l 0.000 lbs/day
Chromium III 200.45 ug/l 0.016 lbs/day 4193.72 ug/l 0.343 lbs/day
ChromiumVI 11.00 ug/l 0.001 lbs/day 16.00 ug/l 0.001 lbs/day
Copper 22.51 ug/l 0.002 lbs/day 36.97 ug/l 0.003 lbs/day
Iron 1000.00 ug/l 0.082 lbs/day
Lead 11.82 ug/l 0.001 lbs/day 303.21 ug/l 0.025 lbs/day
Mercury 0.0120 ug/l 0.000 lbs/day 2.40 ug/l 0.000 lbs/day
Nickel 124.75 ug/l 0.010 lbs/day 1122.05 ug/l 0.092 lbs/day
Selenium 4.60 ug/l 0.000 lbs/day 20.00 ug/l 0.002 lbs/day
Silver N/A ug/l N/A lbs/day 22.28 ug/l 0.002 lbs/day
Zinc 286.93 ug/l 0.023 lbs/day 286.93 ug/l 0.023 lbs/day
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Utah Division of Water Quality
Salt Lake City, Utah
* Allowed below discharge
**Chronic Aluminum standard applies only to waters with a pH < 7.0 and a Hardness < 50 mg/l as CaCO3
Metals Standards Based upon a Hardness of 280.29 mg/l as CaCO3
IV. Numeric Stream Standards for Protection of Agriculture
4 Day Average (Chronic) Standard 1 Hour Average (Acute) Standard
Concentration Load*Concentration Load*
Arsenic ug/l lbs/day
Boron ug/l #VALUE!lbs/day
Cadmium ug/l #VALUE!lbs/day
Chromium ug/l lbs/day
Copper ug/l lbs/day
Lead ug/l lbs/day
Selenium ug/l lbs/day
TDS, Summer mg/l tons/day
V. Numeric Stream Standards for Protection of Human Health (Class 1C Waters)
4 Day Average (Chronic) Standard 1 Hour Average (Acute) Standard
Metals Concentration Load*Concentration Load*
Arsenic 50.0 ug/l 0.433 lbs/day
Barium 1000.0 ug/l 8.660 lbs/day
Cadmium 10.0 ug/l 0.087 lbs/day
Chromium 50.0 ug/l 0.433 lbs/day
Lead 50.0 ug/l 0.433 lbs/day
Mercury 2.0 ug/l 0.017 lbs/day
Selenium 10.0 ug/l 0.087 lbs/day
Silver 50.0 ug/l 0.433 lbs/day
Fluoride (3)1.4 ug/l 0.012 lbs/day
to 2.4 ug/l 0.021 lbs/day
Nitrates as N 10.0 ug/l 0.087 lbs/day
VI. Numeric Stream Standards the Protection of Human Health from Water & Fish Consumption [Toxics]
Maximum Conc., ug/l - Acute Standards
Class 1C Class 3A, 3B
Metals
Antimony 14.0 ug/l 0.12 lbs/day
Arsenic 50.0 ug/l 0.43 lbs/day 4300.00 ug/l 37.24 lbs/day
Asbestos 7.00E+06 ug/l 6.06E+04 lbs/day
Beryllium
Cadmium
Chromium (III)
Chromium (VI)
Copper
Cyanide 1.30E+03 ug/l 11.26 lbs/day 2.2E+05 ug/l 1905.09 lbs/day
Lead 700.0 ug/l 6.06 lbs/day
Mercury 0.15 ug/l 0.00 lbs/day
Nickel 4600.00 ug/l 39.83 lbs/day
Selenium 0.1 ug/l 0.00 lbs/day
Silver 610.0 ug/l 5.28 lbs/day
Thallium 6.30 ug/l 0.05 lbs/day
Zinc
There are additional standards that apply to this receiving water, but were not
considered in this modeling/waste load allocation analysis.
VII. Mathematical Modeling of Stream Quality
Model configuration was accomplished utilizing standard modeling procedures. Data points were
plotted and coefficients adjusted as required to match observed data as closely as possible.
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Utah Division of Water Quality
Salt Lake City, Utah
The modeling approach used in this analysis included one or a combination of the following
models.
(1) The Utah River Model, Utah Division of Water Quality, 1992. Based upon STREAMDO IV
(Region VIII) and Supplemental Ammonia Toxicity Models; EPA Region VIII, Sept. 1990 and
QUAL2E (EPA, Athens, GA).
(2) Utah Ammonia/Chlorine Model, Utah Division of Water Quality, 1992.
(3) AMMTOX Model, University of Colorado, Center of Limnology, and EPA Region 8
(4) Principles of Surface Water Quality Modeling and Control. Robert V. Thomann, et.al.
Harper Collins Publisher, Inc. 1987, pp. 644.
Coefficients used in the model were based, in part, upon the following references:
(1) Rates, Constants, and Kinetics Formulations in Surface Water Quality Modeling. Environmen-
tal Research Laboratory, Office of Research and Development, U.S. Environmental Protection
Agency, Athens Georgia. EPA/600/3-85/040 June 1985.
(2) Principles of Surface Water Quality Modeling and Control. Robert V. Thomann, et.al.
Harper Collins Publisher, Inc. 1987, pp. 644.
VIII. Modeling Information
The required information for the model may include the following information for both the
upstream conditions at low flow and the effluent conditions:

Flow, Q, (cfs or MGD)D.O. mg/l
Temperature, Deg. C.Total Residual Chlorine (TRC), mg/l
pH Total NH3-N, mg/l
BOD5, mg/l Total Dissolved Solids (TDS), mg/l
Metals, ug/l Toxic Organics of Concern, ug/l
Other Conditions
In addition to the upstream and effluent conditions, the models require a variety of physical and
biological coefficients and other technical information. In the process of actually establishing the
permit limits for an effluent, values are used based upon the available data, model calibration,
literature values, site visits and best professional judgement.
Model Inputs
The following is upstream and discharge information that was utilized as inputs for the analysis.
Dry washes are considered to have an upstream flow equal to the flow of the discharge.
Current Upstream Information
Stream
Critical Low
Flow Temp.pH T-NH3 BOD5 DO TRC TDS
cfs Deg. C mg/l as N mg/l mg/l mg/l mg/l
Summer (Irrig. Season)1.6 10.7 8.2 0.03 3.80 8.19 0.00 717.6
Fall 1.5 6.9 8.1 0.03 2.80 --- 0.00 428.1
Winter 1.4 6.0 8.1 0.03 2.30 --- 0.00 428.1
Spring 2.2 9.7 8.1 0.03 2.30 --- 0.00 428.1
Dissolved Al As Cd CrIII CrVI Copper Fe Pb
Metals ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l
All Seasons 16.80 2.50 0.50 3.40 2.65*6.00 15.0 1.50
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Utah Division of Water Quality
Salt Lake City, Utah
Dissolved Hg Ni Se Ag Zn Boron
Metals ug/l ug/l ug/l ug/l ug/l ug/l
All Seasons 0.0000 5.00 0.50 1.00 15.00 10.0 * 1/2 MDL
Projected Discharge Information

Season Flow, MGD Temp.TDS mg/l TDS
tons/day
Summer 0.00980 14.0 387.94 0.01585
Fall 0.00980 10.1
Winter 0.00980 6.5
Spring 0.00980 9.9
All model numerical inputs, intermediate calculations, outputs and graphs are available for
discussion, inspection and copy at the Division of Water Quality.
IX. Effluent Limitations
Current State water quality standards are required to be met under a variety of conditions including
in-stream flows targeted to the 7-day, 10-year low flow (R317-2-9).
Other conditions used in the modeling effort coincide with the environmental conditions expected
at low stream flows.
Effluent Limitation for Flow based upon Water Quality Standards
In-stream criteria of downstream segments will be met with an effluent flow maximum value as follows:
Season Daily Average
Summer 0.010 MGD 0.015 cfs
Fall 0.010 MGD 0.015 cfs
Winter 0.010 MGD 0.015 cfs
Spring 0.010 MGD 0.015 cfs
Flow Requirement or Loading Requirement
The calculations in this wasteload analysis utilize the maximum effluent discharge flow of 0.0098 MGD. If the
discharger is allowed to have a flow greater than 0.0098 MGD during 7Q10 conditions, and effluent limit
concentrations as indicated, then water quality standards will be violated. In order to prevent this from occuring,
the permit writers must include the discharge flow limititation as indicated above; or, include loading effluent
limits in the permit.
Effluent Limitation for Whole Effluent Toxicity (WET) based upon WET Policy
Effluent Toxicity will not occur in downstream segements if the values below are met.
WET Requirements LC50 >3.2%Effluent [Acute]
IC25 >0.9%Effluent [Chronic]
Season
Receiving
Water Flow
(cfs)
Effluent
Flow (MGD)
Effluent
Flow (cfs)
Combined
Flow (cfs)
Totally
Mixed
Chronic
IC25 %
Effluent
Acute
LC50 %
Effluent
Summer 1.59 0.0 0.0 1.6 NO 0.9%0.1%
Fall 1.47 0.0 0.0 1.5 NO 1.0%0.1%
Winter 1.45 0.0 0.0 1.5 NO 1.0%0.1%
Spring 2.24 0.0 0.0 2.3 NO 0.7%0.0%
Effluent Limitation for Biological Oxygen Demand (BOD) based upon Water Quality
Standards or Regulations
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Utah Division of Water Quality
Salt Lake City, Utah
In-stream criteria of downstream segments for Dissolved Oxygen will be met with an effluent BOD
limitation as follows:
Season Concentration
Summer 10.6 mg/l as BOD5 0.9 lbs/day
Fall 10.6 mg/l as BOD5 0.9 lbs/day
Winter 10.6 mg/l as BOD5 0.9 lbs/day
Spring 10.6 mg/l as BOD5 0.9 lbs/day
Effluent Limitation for Dissolved Oxygen (DO) based upon Water Quality Standards
In-stream criteria of downstream segments for Dissolved Oxygen will be met with an effluent
D.O. limitation as follows:
Season Concentration
Summer 6.00
Fall 6.00
Winter 6.00
Spring 6.00
Effluent Limitation for Total Ammonia based upon Water Quality Standards
In-stream criteria of downstream segments for Total Ammonia will be met with an effluent
limitation (expressed as Total Ammonia as N) as follows:
Season
Concentration Load
Summer 4 Day Avg. - Chronic 217.6 mg/l as N 17.8 lbs/day
1 Hour Avg. - Acute 143.3 mg/l as N 11.7 lbs/day
Fall 4 Day Avg. - Chronic 338.7 mg/l as N 27.7 lbs/day
1 Hour Avg. - Acute 238.0 mg/l as N 19.4 lbs/day
Winter 4 Day Avg. - Chronic 233.6 mg/l as N 19.1 lbs/day
1 Hour Avg. - Acute 179.7 mg/l as N 14.7 lbs/day
Spring 4 Day Avg. - Chronic 224.9 mg/l as N 18.4 lbs/day
1 Hour Avg. - Acute 159.4 mg/l as N 13.0 lbs/day
Acute limit calculated with an Acute Zone of Initial Dilution (ZID) to be equal to 50.%.
Effluent Limitation for Total Residual Chlorine based upon Water Quality Standards
In-stream criteria of downstream segments for Total Residual Chlorine will be met with an effluent
limitation as follows:
Season Concentration Load
Summer 4 Day Avg. - Chronic 1.061 mg/l 0.09 lbs/day
1 Hour Avg. - Acute 0.964 mg/l 0.08 lbs/day
Fall 4 Day Avg. - Chronic 0.981 mg/l 0.08 lbs/day
1 Hour Avg. - Acute 0.892 mg/l 0.07 lbs/day
Winter 4 Day Avg. - Chronic 0.966 mg/l 0.08 lbs/day
1 Hour Avg. - Acute 0.879 mg/l 0.07 lbs/day
Spring 4 Day Avg. - Chronic 1.486 mg/l 0.12 lbs/day
1 Hour Avg. - Acute 1.347 mg/l 0.11 lbs/day
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Utah Division of Water Quality
Salt Lake City, Utah
Effluent Limitations for Total Dissolved Solids based upon Water Quality Standards
Season Concentration Load
Summer Maximum, Acute 51834.4 mg/l 2.12 tons/day
Fall Maximum, Acute 82230.9 mg/l 3.36 tons/day
Winter Maximum, Acute 82146.6 mg/l 3.36 tons/day
Spring 4 Day Avg. - Chronic 75798.6 mg/l 3.10 tons/day
Colorado Salinity Forum Limits Determined by Permitting Section
Effluent Limitations for Total Recoverable Metals based upon
Water Quality Standards
In-stream criteria of downstream segments for Dissolved Metals will be met with an effluent
limitation as follows (based upon a hardness of 280.29 mg/l):
4 Day Average 1 Hour Average
Concentration Load Concentration Load
Aluminum N/A N/A 39,232.5 ug/l 3.2 lbs/day
Arsenic 15,633.27 ug/l 0.8 lbs/day 18,053.9 ug/l 1.5 lbs/day
Cadmium 138.06 ug/l 0.0 lbs/day 252.5 ug/l 0.0 lbs/day
Chromium III 20,885.04 ug/l 1.1 lbs/day 224,125.4 ug/l 18.3 lbs/day
Chromium VI 748.42 ug/l 0.0 lbs/day 647.1 ug/l 0.1 lbs/day
Copper 1,755.25 ug/l 0.1 lbs/day 1,662.4 ug/l 0.1 lbs/day
Iron N/A N/A 52,698.4 ug/l 4.3 lbs/day
Lead 1,094.65 ug/l 0.1 lbs/day 16,138.5 ug/l 1.3 lbs/day
Mercury 1.27 ug/l 0.0 lbs/day 128.4 ug/l 0.0 lbs/day
Nickel 12,695.07 ug/l 0.7 lbs/day 59,751.1 ug/l 4.9 lbs/day
Selenium 434.98 ug/l 0.0 lbs/day 1,043.5 ug/l 0.1 lbs/day
Silver N/A ug/l N/A lbs/day 1,139.1 ug/l 0.1 lbs/day
Zinc 28,831.78 ug/l 1.5 lbs/day 14,559.4 ug/l 1.2 lbs/day
Cyanide (free)551.05 ug/l 0.0 lbs/day 1,176.7 ug/l 0.1 lbs/day
Effluent Limitations for Heat/Temperature based upon
Water Quality Standards
Summer 100.0 Deg. C.212.0 Deg. F
Fall 89.7 Deg. C.193.4 Deg. F
Winter 87.5 Deg. C.189.6 Deg. F
Spring 100.0 Deg. C.212.0 Deg. F
Effluent Limitations for Organics [Pesticides]
Based upon Water Quality Standards
In-stream criteria of downstream segments for Organics [Pesticides]
will be met with an effluent limit as follows:
4 Day Average 1 Hour Average
Concentration Load Concentration Load
Aldrin 1.5E+00 ug/l 1.90E-04 lbs/day
Chlordane 4.30E-03 ug/l 3.51E-04 lbs/day 1.2E+00 ug/l 1.52E-04 lbs/day
DDT, DDE 1.00E-03 ug/l 8.17E-05 lbs/day 5.5E-01 ug/l 6.95E-05 lbs/day
Dieldrin 1.90E-03 ug/l 1.55E-04 lbs/day 1.3E+00 ug/l 1.58E-04 lbs/day
Endosulfan 5.60E-02 ug/l 4.58E-03 lbs/day 1.1E-01 ug/l 1.39E-05 lbs/day
Endrin 2.30E-03 ug/l 1.88E-04 lbs/day 9.0E-02 ug/l 1.14E-05 lbs/day
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Utah Division of Water Quality
Salt Lake City, Utah
Guthion 0.00E+00 ug/l 0.00E+00 lbs/day 1.0E-02 ug/l 1.26E-06 lbs/day
Heptachlor 3.80E-03 ug/l 3.11E-04 lbs/day 2.6E-01 ug/l 3.29E-05 lbs/day
Lindane 8.00E-02 ug/l 6.54E-03 lbs/day 1.0E+00 ug/l 1.26E-04 lbs/day
Methoxychlor 0.00E+00 ug/l 0.00E+00 lbs/day 3.0E-02 ug/l 3.79E-06 lbs/day
Mirex 0.00E+00 ug/l 0.00E+00 lbs/day 1.0E-02 ug/l 1.26E-06 lbs/day
Parathion 0.00E+00 ug/l 0.00E+00 lbs/day 4.0E-02 ug/l 5.06E-06 lbs/day
PCB's 1.40E-02 ug/l 1.14E-03 lbs/day 2.0E+00 ug/l 2.53E-04 lbs/day
Pentachlorophenol 1.30E+01 ug/l 1.06E+00 lbs/day 2.0E+01 ug/l 2.53E-03 lbs/day
Toxephene 2.00E-04 ug/l 1.63E-05 lbs/day 7.3E-01 ug/l 9.23E-05 lbs/day
Effluent Targets for Pollution Indicators
Based upon Water Quality Standards
In-stream criteria of downstream segments for Pollution Indicators
will be met with an effluent limit as follows:
1 Hour Average
Concentration Loading
Gross Beta (pCi/l)50.0 pCi/L
BOD (mg/l)5.0 mg/l 0.4 lbs/day
Nitrates as N 4.0 mg/l 0.3 lbs/day
Total Phosphorus as P 0.05 mg/l 0.0 lbs/day
Total Suspended Solids 90.0 mg/l 7.4 lbs/day
Note: Pollution indicator targets are for information purposes only.
Effluent Limitations for Protection of Human Health [Toxics Rule]
Based upon Water Quality Standards (Most stringent of 1C or 3A & 3B as appropriate.)
In-stream criteria of downstream segments for Protection of Human Health [Toxics]
will be met with an effluent limit as follows:
Maximum Concentration
Concentration Load
Metals
Antimony 1483.60 ug/l 0.12 lbs/day
Arsenic 5036.14 ug/l 0.41 lbs/day
Asbestos 7.42E+08 ug/l 6.06E+04 lbs/day
Beryllium
Cadmium
Chromium (III)
Chromium (VI)
Copper 137762.75 ug/l 11.26 lbs/day
Cyanide 74179.94 ug/l 6.06 lbs/day
Lead 0.00 0.00
Mercury 14.83 ug/l 0.00 lbs/day
Nickel 64642.52 ug/l 5.28 lbs/day
Selenium 0.00 0.00
Silver 0.00 0.00
Thallium 180.15 ug/l 0.01 lbs/day
Zinc
Metals Effluent Limitations for Protection of All Beneficial Uses
Based upon Water Quality Standards and Toxics Rule
Class 4
Acute
Agricultural
Class 3
Acute
Aquatic
Wildlife
Acute
Toxics
Drinking
Water
Source
Acute Toxics
Wildlife
1C Acute
Health
Criteria
Acute Most
Stringent
Class 3
Chronic
Aquatic
Wildlife
Page 7
Utah Division of Water Quality
Salt Lake City, Utah
ug/l ug/l ug/l ug/l ug/l ug/l ug/l
Aluminum 39232.5 39232.5 N/A
Antimony 1483.6 455676.8 1483.6
Arsenic 18053.9 5036.1 0.0 5036.1 15633.3
Asbestos 7.42E+08 7.42E+08
Barium 105971.3 105971.3
Beryllium 0.0
Cadmium 252.5 0.0 252.5 138.1
Chromium (III)224125.4 0.0 224125.4 20885.0
Chromium (VI)647.1 0.0 647.14 748.42
Copper 1662.4 137762.7 1662.4 1755.2
Cyanide 1176.7 23313695.9 1176.7 551.1
Iron 52698.4 52698.4
Lead 16138.5 0.0 16138.5 1094.7
Mercury 128.37 14.8 15.90 0.0 14.83 1.271
Nickel 59751.1 64642.5 487468.2 59751.1 12695.1
Selenium 1043.5 0.0 1043.5 435.0
Silver 1139.1 0.0 1139.1
Thallium 180.2 667.6 180.2
Zinc 14559.4 14559.4 28831.8
Boron 73896.1 73896.1
Summary Effluent Limitations for Metals [Wasteload Allocation, TMDL]
[If Acute is more stringent than Chronic, then the Chronic takes on the Acute value.]
WLA Acute WLA Chronic
ug/l ug/l
Aluminum 39232.5 N/A
Antimony 1483.60
Arsenic 5036.1 15633.3 Acute Controls
Asbestos 7.42E+08
Barium
Beryllium
Cadmium 252.5 138.1
Chromium (III)224125.4 20885
Chromium (VI)647.1 748.4 Acute Controls
Copper 1662.4 1755.2 Acute Controls
Cyanide 1176.7 551.1
Iron 52698.4
Lead 16138.5 1094.7
Mercury 14.835 1.271
Nickel 59751.1 12695
Selenium 1043.5 435.0
Silver 1139.1 N/A
Thallium 180.2
Zinc 14559.4 28831.8 Acute Controls
Boron 73896.13
Other Effluent Limitations are based upon R317-1.
E. coli 126.0 organisms per 100 ml
X. Antidegradation Considerations
The Utah Antidegradation Policy allows for degradation of existing quality where it is determined
that such lowering of water quality is necessary to accommodate important economic or social
development in the area in which the waters are protected [R317-2-3]. It has been determined that
certain chemical parameters introduced by this discharge will cause an increase of the concentration of
said parameters in the receiving waters. Under no conditions will the increase in concentration be
allowed to interfere with existing instream water uses.
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Utah Division of Water Quality
Salt Lake City, Utah
The antidegradation rules and procedures allow for modification of effluent limits less than those based
strictly upon mass balance equations utilizing 100% of the assimilative capacity of the receiving water.
Additional factors include considerations for "Blue-ribbon" fisheries, special recreational areas,
threatened and endangered species, and drinking water sources.
An Antidegradation Level I Review was conducted on this discharge and its effect on the
receiving water. Based upon that review, it has been determined that an
Antidegradation Level II Review is required because it is a new permit issuance.
XI. Colorado River Salinity Forum Considerations
Discharges in the Colorado River Basin are required to have their discharge at a TDS loading
of less than 1.00 tons/day unless certain exemptions apply. Refer to the Forum's Guidelines
for additional information allowing for an exceedence of this value.
This doesn’t apply to facilities that do not discharge to the Colorado River Basin.
XII. Summary Comments
The mathematical modeling and best professional judgement indicate that violations of receiving
water beneficial uses with their associated water quality standards, including important down-
stream segments, will not occur for the evaluated parameters of concern as discussed above if the
effluent limitations indicated above are met.
XIII. Notice of UPDES Requirement
This Addendum to the Statement of Basis does not authorize any entity or party to discharge to the
waters of the State of Utah. That authority is granted through a UPDES permit issued by the Utah
Division of Water Quality. The numbers presented here may be changed as a function of other
factors. Dischargers are strongly urged to contact the Permits Section for further information.
Permit writers may utilize other information to adjust these limits and/or to determine other limits
based upon best available technology and other considerations provided that the values in this
wasteload analysis [TMDL] are not compromised. See special provisions in Utah Water Quality
Standards for adjustments in the Total Dissolved Solids values based upon background concentration.
Utah Division of Water Quality
801-538-6052
File Name: 240528-SLCDPW_Parleys_WTF_WLA_2024.xlsm
APPENDIX - Coefficients and Other Model Information
CBOD CBOD CBOD REAER.REAER.REAER.NBOD NBOD
Coeff.Coeff.Coeff.Coeff.Coeff.Coeff.Coeff.Coeff.
(Kd)20 FORCED (Ka)T (Ka)20 FORCED (Ka)T (Kn)20 (Kn)T
1/day (Kd)/day 1/day (Ka)/day 1/day 1/day 1/day 1/day
2.000 0.000 1.307 276.349 0.000 221.828 0.400 0.196
Open Open NH3 NH3 NO2+NO3 NO2+NO3 TRC TRC
Coeff.Coeff.LOSS LOSS Decay
(K4)20 (K4)T (K5)20 (K5)T (K6)20 (K6)T K(Cl)20 K(Cl)(T)
1/day 1/day 1/day 1/day 1/day 1/day 1/day 1/day
0.000 0.000 4.000 2.614 0.000 0.000 32.000 18.649
BENTHIC BENTHIC
DEMAND DEMAND
(SOD)20 (SOD)T
gm/m2/day gm/m2/day
1.000 0.558
Page 9
Utah Division of Water Quality
Salt Lake City, Utah
K1 K2 K3 K4 K5 K6 K(Cl)S
CBOD Reaer. NH3 Open NH3 Loss NO2+3 TRC Benthic
{theta} {theta} {theta} {theta} {theta} {theta}{theta} {theta}
1.0 1.0 1.1 1.0 1.0 1.0 1.1 1.1
Antidegredation Review
An antidegradation review (ADR) was conducted to determine whether the proposed activity complies with the
applicable antidegradation requirements for receiving waters that may be affected. The Level I ADR evaluated
the criteria of R317-2-3.5(b) and determined that a Level II antidegradation Review is required because this is a
new permit authorization.
Page 10
Freshwater total ammonia criteria based on Title R317-2-14 Utah Administrative Code
Acute
Summer Fall Winter Spring
pH:8.20 8.13 8.10 8.05
Beneficial use classification:3A 3A 3A 3A
Acute (Class 3A):3.826 4.374 4.664 5.065
Acute (Class 3B, 3C, 3D):5.729 6.549 6.983 7.584
INPUT
OUTPUT
Total ammonia nitrogen criteria (mg N/L):
Page B-11
Freshwater total ammonia criteria based on Title R317-2-14 Utah Administrative Code
Chronic
Summer Fall Winter Spring
Temperature (deg C):10.73 6.88 5.99 9.69
pH:8.20 8.13 8.10 8.05
Are fish early life stages present?Yes Yes Yes Yes
Total ammonia nitrogen criteria (mg N/L):
Chronic - Fish Early Life Stages Present:1.794 2.000 2.105 2.247
Chronic - Fish Early Life Stages Absent:2.289 3.248 3.419 3.067
INPUT
OUTPUT
Page B-12