DWQ-2025-005084

Utah Division of Water Quality
WASTELOAD ANALYSIS [WLA]Date:6/24/2025
Appendix A: Mass Balance Mixing Analysis for Conservative Constituents
A Level II Antidegradation Review (ADR) is required for this facility.
Discharging Facility:Emery County Coal Resources, Inc - Lilla Canyon Mine
UPDES No:UT0026018
Lila Canyon Wash to Grassy Wash to Marsh Flats Wash to Price River to Green River
Permit Flow [MGD]:3.00000 Annual Max. Daily 3.00000 Annual Max. Monthly
Receiving Water:Lila Canyon Wash to Grassy Wash to Marsh Flats Wash to Price River to Green River
Stream Classification:2B,3C,4
Stream Flows [cfs]:0.00 All Seasons Critical Low Flow ephemeral stream
- All Seasons Critical Low Flow (20th %)ephemeral stream
Fully Mixed:YES
Acute River Width:100%
Chronic River Width:100%
Modeling Information A mass balance mixing analysis was used to determine the effluent limits.
All model numerical inputs, intermediate calculations, outputs and graphs are available for
discussion, inspection and copy at the Division of Water Quality.
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 reflect the environmental conditions expected
at low stream flows.
The calculations in this wasteload analysis utilize the maximum effluent discharge flow of 3 MGD. If the discharger is allowed to have a flow greater than 3 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.
Technology Based Effluent Limits Limit
Total Phosphorus as P 1.00 mg/L
Effluent Limitations for Protection of Recreation (Class 2B Waters) (R317-2-14.1)
Physical Parameter Minimum MaximumpH6.5 9.0
Turbidity Increase (NTU)10.0
Bacteriological (R317-2-14.1)
E. coli (30 Day Geometric Mean)206 (#/100 mL)
E. coli (Maximum)668 (#/100 mL)
Effluent Limitations for Protection of Aquatic Wildlife (Class 3C Waters) (R317-2-14.2)
Physical
Parameter Minimum Maximum
pH 6.5 9.0Turbidity Increase (NTU)15.0Temperature (deg C)27
Temperature Change (deg C)4
Dissolved Oxygen (mg/L)Minimum Concentration
Concentration
Concentration
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Utah Division of Water Quality
ELS Present Others Present
Instantaneous 3.0 3.0
30-day Average 5.0 5
7-day Average
Inorganics Chronic (30-day ave)Acute (1-hour ave)
Parameter Standard
Phenol (mg/L)0.010
Hydrogen Sulfide (Undissociated-mg/L)0.002Total Residual Chlorine (mg/L)0.011 0.019
Ammonia-Total (mg/L)
Chronic (30-day ave)Acute (1-hour ave)
Season Standard Background Limit Standard Background Limit
Summer 2.2 2.2 7.8 7.8
Fall 1.8 1.8 5.6 5.6
Winter 2.5 2.5 8.7 8.7
Spring 2.0 2.0 6.6 6.6
Season Standard Background Limit Standard Background LimitSummer2.2 2.2 7.8 7.8
Fall 2.1 2.1 5.6 5.6
Winter 3.3 3.3 8.7 8.7
Spring 2.4 2.4 6.6 6.6
Metals-Total Recoverable
Chronic (4-day ave)Acute (1-hour ave)
Parameter Standard1 Background Limit Standard1 Background Limit
Aluminum (µg/L)750.0 750.0
Arsenic (µg/L)150.0 150.0 340.0 340.0
Cadmium (µg/L)2.4 2.4 7.4 7.4
Chromium VI (µg/L)11.0 11.0 16.0 16.0Chromium III (µg/L)268.2 268.2 5,612 5,612Copper (µg/L)30.5 30.5 51.7 51.7Cyanide (µg/L)2 5.2 5.2 22.0 22.0
Iron (µg/L)1,000 1,000
Lead (µg/L)18.6 18.6 476.8 476.8Mercury (µg/L)2 0.012 0.012 2.4 2.4
Nickel (µg/L)168.5 168.5 1,516 1,516
Selenium (µg/L)4.6 4.6 18.4 18.4
Silver (µg/L)41.1 41.1Tributylin (µg/L)2 0.072 0.072 0.46 0.46
Zinc (µg/L)387.8 387.8 387.8 387.8
1: Based upon a Hardness of 400 mg/l as CaCO3
2: Background concentration assumed 67% of chronic standard
Organics [Pesticides]Chronic (4-day ave)Acute (1-hour ave)
Parameter Standard Limit Standard Limit
Aldrin (µg/L)1.5 1.5
Chlordane (µg/L)0.0043 0.0043 1.2 1.2
DDT, DDE (µg/L)0.001 0.001 0.55 0.55
Diazinon (µg/L)0.17 0.17 0.17 0.17
Dieldrin (µg/L)0.0056 0.0056 0.24 0.24
Endosulfan, a & b (µg/L)0.056 0.056 0.11 0.11
Endrin (µg/L)0.036 0.036 0.086 0.086
Heptachlor & H. epoxide (µg/L)0.0038 0.0038 0.26 0.26Lindane (µg/L)0.08 0.08 1.0 1.0Methoxychlor (µg/L)0.03 0.03
Mirex (µg/L)0.001 0.001
Nonylphenol (µg/L)6.6 6.6 28.0 28.0
Parathion (µg/L)0.0130 0.0130 0.066 0.066
ELS Present
ELS Absent
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Utah Division of Water Quality
PCB's (µg/L)0.014 0.014
Pentachlorophenol (µg/L)15.0 15.0 19.0 19.0
Toxephene (µg/L)0.0002 0.0002 0.73 0.73
Radiological Maximum Concentration
Parameter Standard
Gross Alpha (pCi/L)15
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