Reasonable Potential Analysis & Impacts to Pretreatment Programs Raj Kapur Clean Water Services
Agenda Water Quality Standards (WQS) & Recent Changes Reasonable Potential Analysis Pollutants of Concern Compliance Strategies Conclusions
Water Quality Standards States responsible for adopting WQS Components Designated uses Numeric or narrative criteria Criteria Aquatic life Human health Reviewed every 3 years EPA has oversight authority
What s Changed in WQS? Increased focus on toxic pollutants Human health standards Based on higher fish consumption rates 6.5 g/day vs.175 g/day ~30X more stringent for carcinogens Aquatic life standards DEQ proposal, EPA response Total recoverable and dissolved standards
Reasonable Potential Analysis What: Statistical approach to evaluate if a discharge results in exceeding water quality criterion Method: EPA s Technical Support Document for Water Quality Based Toxics Control (March 1991) When: Permit renewal (typically)
RPA Spreadsheet Sample Facility Name: DEQ File Number: Permit Writer Name: Outfall Number: Date of RPA Run: 111111 Ace Permit Writer 001 8/1/2014 2. Is the receiving waterbody y Dilution @ ZID (from study) fresh water? (Y/N) 4.9 3. If answered "N" to Question Dilution @ MZ (from study) 10.2 1, then fill in the following table 5. Please enter Water Hardness Data below to reflect Eff. Flow Rate MGD * critical conditions (values from 25 to 400 mg/l) Stream Flow: 7Q10 CFS * Effluent mg/l CaCO 3 117.25 Stream Flow: 1Q10 CFS * Up-stream mg/l CaCO 3 25 % dilution at ZID % 10% ZID boundary mg/l CaCO 3 44 RPA Run Notes: % dilution at MZ % 25% MZ boundary mg/l CaCO 3 34 Calculated dilution Factors 6. Please enter statistical Confidence and Probablity Dilution @ ZID na values (note: defaults already entered) KEY: -- Intermediate calc.s Dilution @ MZ na Confidence Level % 99% * Enter data here -- Calculated results Probability Basis % 95% Determine Monitoring Reqs. Pollutant Parameter RPA Run Information Evaluation Required? Douglas Fir # of Samples Identify Pollutants of Concern Highest Effluent Conc. Coefficent of Variation Please complete the following General Facility Information 1. Do I have dilution values from a mixing zone study? (Y/N) Estimated Max Eff. Conc. RP at end of pipe? (Y/N) µg/l Default=0.6 µg/l (Y/N) µg/l µg/l µg/l µg/l µg/l Acute Chronic Table 1 Effluent Parameters for all POTWs w/a Flow > 0.1 MGD Ammonia (as N) * Evaluation occurs on Ammonia (NH3) spreadsheet page, No HH criteria Chlorine (total residual, TRC) * Evaluation occurs on Chlorine (-Cl) spreadsheet page, no HH criteria Dissolved oxygen * Evaluation occurs on Dissolved Oxygen (DO) spreadsheet page Oil and Grease * Compare to Effluent limits in permits or Federal Effluent Limit Guidelines Total dissolved solids * Compare to Effluent limits in permits or Federal Effluent Limit Guidelines Table 2 Effluent Parameters for Selected POTWs Hardness (Total as CaCO3) Must be collected for metals criteria calculation. Submit data to the fields at the top of the spreadsheet Table 2: Metals (total recoverable), cyanide and totoal phenols Arsenic (Total) Yes 4 1.51 No Water Quality Criteria 0.00 ARSENIC III No 4 1.51 0.60 4.83 No 0 0.99 0.47 360.0 190.0 NO NO Cadmium Yes 8 0.132 0.60 0.30 Yes 1.00 0.86 0.93 1.5 0.1 NO YES Chromium (total) Yes 4 1.22 No Water Quality Criteria * Chromium III Yes 4 1.22 0.60 3.90 No * -- -- 289.9 30.7 -- -- Chromium VI Yes 4 1.22 0.60 3.90 No * -- -- 15.7 10.6 -- -- Copper Yes 8 26.6 0.60 61.18 Yes 3.00 14.87 8.70 8.1 4.7 YES YES Iron Yes 4 126 0.60 403.20 No * -- -- -- 1000 -- -- Lead Yes 80 0.819 0.60 0.82 Yes 5.00 4.15 4.59 26.0 0.8 NO YES Mercury Yes 100 0.064 0.60 0.06 Yes 0.01 0.02 0.02 2.4 0.012 NO YES Nickel Yes 4 2.46 0.60 7.87 No * -- -- 233.0 20.9 -- -- Selenium Yes 4 3.11 0.60 9.95 No * -- -- 260.0 35.0 -- -- Silver Yes 8 0.092 0.60 0.21 Yes 0.10 0.12 0.11 0.8 0.1 NO YES Zinc Yes 8 63.1 0.60 145.13 Yes 5.00 33.60 18.74 58.3 47.4 NO NO Cyanide (Free) Yes 4 1.60 0.60 5.12 No * -- -- 22.0 5.2 -- -- Cyanide (Total) Yes 4 1.6 No Water Quality Criteria * y Determine In-Stream Conc. Ambient Conc. 4. If answered "Y" to Question 1, then fill in dilution factors from mixing zone study Max Total Max Total Conc. at ZID Conc. at RMZ Determine Reasonable Potential WQ CRITERIA 1 Hour 4 Day (CMC) (CCC) Is there Reasonable Potential to Exceed? (Y/N)
Answers Two Basic Questions Is there reasonable potential to exceed water quality criterion? If yes, what effluent limits should be established to meet the water quality criterion?
Visualization of RPA Process Stream Data Dilution 1 5 10 20 Effluent Data
Inputs
Considerations If RP, NPDES permit must contain an effluent limit (CFR 122.44(d)(1)(ii)) Repercussions are significant Compliance can be expensive Impacts to industry through local limits
Effluent data Preparing for RP Analysis No. of samples, concentration, and distribution Ensure robust dataset to characterize effluent Establish frequencies based on data available at permit renewal Consider seasonality Receiving stream background data Determines assimilative capacity For pollutants for which criteria are not met at end of pipe Evaluate availability of existing data Consider flow regimes/seasonality
Preparing for RP Analysis cont d What is a mixing zone? Mixing dependent on stream flow WQ Criteria evaluated for different flow conditions 1Q10/7Q10 30Q5 Harmonic mean Evaluate other critical time periods/flow conditions
Initial Analysis (Aquatic Life) Facility Name: WWTF discharge (2025 conditions) Aquatic Life Protection Spreadsheet Dilution Values? (Y/N) Y calculated Hardness mg/l CaCO 3 Dilution @ ZID 1.8 * Effluent 119 Dilution @ MZ 6 * Stream 32 If no dilution values enter info below Mixed Facility Effluent Flow * MGD ZID 80 7Q10 * CFS MZ 47 1Q10 * CFS % dilution at ZID * % Confidence Level 99% % dilution at MZ * % Probability Basis 95% Fresh Water? (Y/N) Y Date: 08/30/2013 Highest Calculated Background Maximum Maximum WQ CRITERIA REASONABLE # of Conc. Coef. of Max Effluent Conc. Conc. at Conc. at 1 Hour 4 Day POTENTIAL? PARAMETER Samples See IMD Varience Conc. See IMD ZID MZ (CMC) (CCC) µg/l µg/l µg/l µg/l µg/l µg/l µg/l ACUTE CHRONIC ANTIMONY * 42 0.31 0.34 0.34 0.05 0.21 0.10 9000 1600 NO NO CADMIUM + 42 0.17 0.34 0.19 0.03 0.12 0.06 3.06 0.62 NO NO CHROMIUM III + 42 0.94 0.27 1.03 1.75 1.35 1.63 1451 111 NO NO COPPER + 42 13.2 0.36 14.52 4.8 10.20 6.42 14.4 6.1 NO YES CYANIDE 42 2.5 0.60 3.00 2.5 2.78 2.58 22.0 5.2 NO NO LEAD + 42 0.7 0.56 0.84 0.43 0.66 0.50 62 1.20 NO NO MERCURY 42 0.0000169 0.67 0.000022 0.0000045 0.000014 0.000007 2.40 0.012 NO NO NICKEL + 42 19.3 0.93 27.02 1.5 15.68 5.75 1178 82 NO NO SELENIUM 42 0.59 0.60 0.71 0.25 0.50 0.33 260 35 NO NO SILVER + 42 0.69 0.95 0.97 0.015 0.54 0.17 2.78 0.12 NO YES THALLIUM * 42 0.01 0.60 0.01 0.01 0.01 0.01 1400 40 NO NO ZINC + 42 44.9 0.29 49.39 8.1 31.04 14.98 97 55 NO NO Custom * * * * * * * * * -- --
Screening Level Evaluation
Copper - Dry Season Facility Name: WWTF discharge (2025 conditions - dry season) Aquatic Life Protection Spreadsheet Dilution Values? (Y/N) Y calculated Hardness mg/l CaCO 3 Dilution @ ZID 1.8 * Effluent 125 Dilution @ MZ 6 * Stream 34 If no dilution values enter info below Mixed Facility Effluent Flow * MGD ZID 85 7Q10 * CFS MZ 49 1Q10 * CFS % dilution at ZID * % Confidence Level 99% % dilution at MZ * % Probability Basis 95% Fresh Water? (Y/N) Y Date: 08/30/2013 Highest Calculated Background Maximum Maximum WQ CRITERIA REASONABLE # of Conc. Coef. of Max Effluent Conc. Conc. at Conc. at 1 Hour 4 Day POTENTIAL? PARAMETER Samples See IMD Varience Conc. See IMD ZID MZ (CMC) (CCC) µg/l µg/l µg/l µg/l µg/l µg/l µg/l ACUTE CHRONIC COPPER + 21 9.2 0.38 11.96 4.8 8.78 5.99 15.1 6.4 NO NO
Copper Wet Season Facility Name: WWTF discharge - wet season (2025 conditions) Aquatic Life Protection Spreadsheet Dilution Values? (Y/N) Y calculated Hardness mg/l CaCO 3 Dilution @ ZID 2.5 * Effluent 112 Dilution @ MZ 7.8 * Stream 30 If no dilution values enter info below Mixed Facility Effluent Flow * MGD ZID 63 7Q10 * CFS MZ 41 1Q10 * CFS % dilution at ZID * % Confidence Level 99% % dilution at MZ * % Probability Basis 95% Fresh Water? (Y/N) Y Date: 08/30/2013 Highest Calculated Background Maximum Maximum WQ CRITERIA REASONABLE # of Conc. Coef. of Max Effluent Conc. Conc. at Conc. at 1 Hour 4 Day POTENTIAL? PARAMETER Samples See IMD Varience Conc. See IMD ZID MZ (CMC) (CCC) µg/l µg/l µg/l µg/l µg/l µg/l µg/l ACUTE CHRONIC COPPER + 21 13.2 0.35 17.16 3.4 8.90 5.16 11.4 5.5 NO NO
Silver Facility Name: WWTF discharge (2025 conditions) Aquatic Life Protection Spreadsheet Dilution Values? (Y/N) Y calculated Hardness mg/l CaCO 3 Dilution @ ZID 1.8 * Effluent 119 Dilution @ MZ 6 * Stream 32 If no dilution values enter info below Mixed Facility Effluent Flow * MGD ZID 80 7Q10 * CFS MZ 47 1Q10 * CFS % dilution at ZID * % Confidence Level 99% % dilution at MZ * % Probability Basis 95% Fresh Water? (Y/N) Y Date: 08/30/2013 Highest Calculated Background Maximum Maximum WQ CRITERIA REASONABLE # of Conc. Coef. of Max Effluent Conc. Conc. at Conc. at 1 Hour 4 Day POTENTIAL? PARAMETER Samples See IMD Varience Conc. See IMD ZID MZ (CMC) (CCC) µg/l µg/l µg/l µg/l µg/l µg/l µg/l ACUTE CHRONIC SILVER + 33 0.29 0.75 0.41 0.015 0.23 0.08 2.78 0.12 NO NO
Hierarchy of RPA Actions Enhanced Data: Effluent data Receiving stream data Dynamic Analysis: Seasonality Mixing zone dilutions
Industrial Chemicals Metals, organics Mercury Temperature Chlorination byproducts THMs (chloroform, bromoform, etc.) Consumer Products/non-industrial phthalates Legacy Pollutants Pollutants of Concern DDT, DDE, aldrin, dieldrin, etc.
Compliance Strategies Domestic Pretreatment Industrial Reuse Education/ outreach Process enhancement/ New Technology Commercial Influent Wastewater WQ Trading Outfall mod./reevaluate mixing zone Use Attainability Analysis Site Specific Criteria Variances 20
Compliance Strategies for Metals Domestic Pretreatment Industrial Reuse Education/ outreach Process enhancement/ New technology Commercial Influent Wastewater WQ Trading Outfall mod./reevaluate mixing zone Use Attainability Analysis Site Specific Criteria Variances 21
Compliance Strategies for Mercury Domestic Pretreatment Industrial Reuse Education/ outreach Process enhancement/ New Technology Commercial Influent Wastewater WQ Trading Outfall mod./reevaluate mixing zone Variances Use Attainability Analysis Site Specific Criteria 22
Compliance Strategies for Temperature Domestic Pretreatment Industrial Reuse Education/ outreach Process enhancement/ New Technology Commercial Influent Wastewater WQ Trading Outfall mod./reevaluate mixing zone Variances Use Attainability Analysis Site Specific Criteria 23
Compliance Strategies for Phthalates Domestic Pretreatment Industrial Reuse Education/ outreach Process enhancement/ New Technology Commercial Influent Wastewater WQ Trading Outfall mod./reevaluate mixing zone Variances Use Attainability Analysis Site Specific Criteria 24
Compliance Strategies for Legacy Domestic Pollutants Pretreatment Industrial Reuse Education/ outreach Process enhancement/ New Technology Commercial Influent Wastewater WQ Trading Outfall mod./reevaluate mixing zone Variances Use Attainability Analysis Site Specific Criteria 25
Conclusions Increased focus on toxic pollutants PT programs need to look beyond their traditional role to tackle these pollutants Recommendations Embrace data Reasonable Potential Analysis Evaluate compliance strategies proactively Best solution for your municipality Oregon Association of Clean Water Agencies 26
Questions?