REGION VIII NPDES WHOLE EFFLUENT TOXICS CONTROL PROGRAM AUGUST 1997 INTRODUCTION This document is the 1997 revision to the original Region VIII Whole Effluent Toxicity (WET) Policy. The contents and procedures supplement and, in the case of conflicts, supersede EPA national guidance and other non-regulatory EPA national documents on this subject. Requirements in this document should be considered minimum, and can be expanded at any time. PURPOSE This program provides significant controls over the discharge of toxicants into waters of the United States in Region VIII. These controls are called for by: 1. Section 101(a)(3) of the Clean Water Act; 2. State Water Quality Standards which uniformly prohibit the discharge of toxicants or require state waters to be free from toxicants; 3. EPA policy dated March 4, 1984 (5); 4. epa's Basic Permitting Principles for Whole Effluent Toxicity, dated January 25, 1989; 5. Surface Water Toxic Control Regulations published on June 2, 1989; 6. Whole Effluent Toxicity (WET) Control Policy, July 1994. GENERAL IMPLEMENTATION PROCEDURE AND SUMMARY OF MODIFICATIONS I. Whole Effluent Controls: The primary impetus for the inclusion of WET limits is 40 CFR 122.44 (d) which states that if a discharger "..causes, has the reasonable potential to cause, or contributes to an in- stream excursion above a narrative criterion within an applicable State water quality standard...", the discharger's permit must contain enforceable WET limits. These regulations also state that numerical limits can be substituted for WET limits if the "...chemical-specific limits for the effluent are sufficient to attain and maintain applicable numeric and narrative State water quality standards." In the case of ammonia and chlorine toxicity, as noted later in this Policy, if the WET is due to these substances, the wasteload allocation process allows high levels of chlorine and ammonia, and numeric limits exist in the WQS for them, the WET requirements may be appropriately modified as long as the numeric and narrative WQS are satisfied. As in the previous revision, chronic limits may still be required if it is concluded that a discharge has the reasonable 1 ------- potential to violate water quality standards exclusively because of chronic toxicity. Under these circumstances, the permit must contain appropriate WET limits to assure correction of the chronic toxicity problem. Thus, as examples, facilities with measured in-stream chronic toxicity, site specific chronic aquatic toxicity information, and environmentally sensitive or pristine receiving waters may need chronic toxicity limits, and/or the acute toxicity limits may have to be less than 50% mortality. Chronic lethality is no longer allowed as a test endpoint. Chronic toxicity is the combined effect on the organisms growth and survival, or reproduction and survival. The 50% mortality acute toxicity definition is continued. The 50% acute limit applies at any test dilution and is applicable at the end of the, pipe. An exemption to this can be granted if the discharger can show conclusively that instantaneous or complete mixing occurs naturally below the discharge, or if a properly designed diffuser is in place. If this is done, dilution can be allowed, and the 50% mortality would be applicable at a dilution concentration commensurate with the applicable instream waste concentration (IWC). In a complete mix situation, the 50% mortality for acute toxicity should be applied at the instream waste concentration based on acute low flows. Region VIII has developed a mixing zone policy which defines a complete mix as. 1) no more than a 10% difference from bank to bank in constituents in a downward distance of two stream widths, or 2) a greater than 1:1 effluent to receiving water volume. The actual amount of dilution allowed should be in conformance with this policy. Selenastrum capricornuturn can be used as a chronic test organism. This plant can be rotated on an alternating basis with the vertebrate or the invertebrate, or used as an'additional test species. This green alga is the same one used as a food source in Ceriodaphnia culturing and testing. The testing protocol is in Appendix B. WET test methods have been codified in 40 CFR part 136. This results in the following changes in Region VIII WET Control Program Policy: 1) Chronic test endpoints must be based on survival and growth, or survival and reproduction. 2) Acute test duration for Pimephales promelas may be shortened to 48 hours. Where testing has demonstrated greater than 20% mortality at 9 6 hours and not at 48 hours, the test duration should remain at 96 hours. 3) On chronic tests, five dilutions and a control are required. 4) First priority for diluent should be the receiving water. If that is unsuitable then moderately hard (80 to 100, expressed as mg. CaC03/L) reconstituted water should be used for diluent. 2 ------- 5) Acute test temperature tolerance is ^C. 6) Pimephales promelas acute test is conducted with 200 mis. test solution in a 250 mis. test container. The chronic test is conducted with 250 mis. test solution in a 500 mis. test container. 7) Age of Pimephales promelas larvae for the acute test should be 1 to 14 days old and born within 24 hours of each other. 8) Replace the statistical NOEC hypothesis testing with the linear interpolation technique (IC25 )as the test statistic on chronic tests. 9) Use of zeolite for routine compliance testing is prohibited. The reporting guidance form has been changed to reflect the following: 1) Test temperatures and test dissolved oxygen readings do not have to be reported. 2) Initial mean weight on Pimephales chronic test do not have to be reported. 3) Line space has been added for recording the temperature of samples upon arrival at the testing laboratory. The use of Toxic Units (TU) in the permit program is being introduced in this revision. Its incorporation in the permit development phase and the compliance reporting phase is recommended. Toxic units are a standard mechanism for quantifying whole effluent toxicity. The TU increases as toxicity increases. Acute Toxic Unit (Tua) is 100/LC5o. As an example, if a sample produced a LC50 of 100% then Tua= 100/100 or 1. Chronic Toxic Unit (Tuc) is 100/IC25 or NOEC. If a sample produced an IC25 or a NOEC of 80%, then Tuc = 100/80 or 1.25. In changing over to the terms above, the permit and reporting requirements for WET should be consistent. If acute WET is limited at 100% effluent the permit limit should be stated as less than 1 Tua. For chronic toxicity, if the IWC is 50%, then the limit would be expressed a Tuc less than 2 (100/50) . Discharge Monitoring Reports will have to be coded appropriately. The basic approach is contained in the block diagrams which vary slightly from state to state and reflect practices in the individual Region VIII states. It is expected that permits for all major and all significant minor dischargers in each state will contain the essence of the relevant diagram. As noted in footnote (1) of the diagrams, exceptions can be made for those facilities where there is no reasonable potential for the discharge of Whole Effluent Toxicity. All permit Statement of Basis should contain a detailed discussion of the reasons for including, or not including, WET limits in a permit based on a reasonable potential determination. This will provide an adequate administrative record should any challenge of the 3 ------- determination be made by a discharger or environmental group. The justification for the inclusion, or exclusion, of limits should contain a discussion of the following as a minimum: a. Existence of a pretreatment program. b. Whether or not categorical industries exist in the system, or in the case of industry, if it is a categorical industry. c. Receiving water characteristics such as classification, Q7-10, dilution ratios, etc. d. Size of the discharge. e. Number of commercial and industrial taps. f. Compliance history. g. History of fish kills in the receiving water. h. Actual data showing WET in the discharge. I. Instream survey data. Flexibility exists in the type of species selected (the discharger must first establish that any alternate species has an equivalent sensitivity), monitoring frequency, and exact dates for implementation by the permittee. Any deviation from the diagram must be justified in the Statement of Basis. All major and minor permits, for which it has been concluded that a reasonable potential to discharge toxicity exists, must require two species testing, and an appropriate immediate or delayed limitation of WET. When permits that have WET limits are renewed, if the renewed permit requirements are similar to the old requirements, the limit is effective immediately. The amount of the delay in the application of limits is discretionary and dependant on physical characteristics, the amount of existing WET effluent data, and other restrictions. All major permits, for which it has been concluded that a reasonable potential to discharge toxicity does not exist, must require two species testing and a reopener clause calling for the inclusion of limits if toxicity occurs. The definition of when toxicity is occurring at a level to warrant further action is left to the regulatory authority; a specific definition can be incorporated in the permit, or it can be left to the judgement of the regulatory authority, much as it is now for all other permit limitations. However as a matter of practice, once a second test demonstrates the continued toxicity problem, initiation of a TRE is warranted. The example TRE language in Appendix A has been reduced to a level where it is clear that the responsibility for compliance with the ultimate WET limits is independent of the quality of any TRE, or whether or not the permittee has been told to do a TRE. It is expected that on rare occasions unanticipated events may occur that will require adjustment in permit conditions to accommodate these unusual circumstances. Appendix A contains recommended permit language to provide flexibility in this eventuality. 4 ------- As noted in the introduction, procedures outlined in this document supplement or supersede previously published guidance and other non-regulatory national documents. The protocols in Appendix B shall prevail in any conflict with other such references. These are from the 40 CFR Part 13 6. Region VIII specifies that the test type is static renewal, acute test temperature is 20°C, acute Ceriodaphnia dubia test is conducted for 48 hours, and acute Pimephales promelas test can be conducted for 48 or 96 hours. In Pimephales promelas test, if previous WET tests have shown greater than 20% mortality at 96 hours and not at 48 hours, then the test should remain at the 96 hour duration. Once the 48 hour testing has been authorized, if >20% mortality occurs in subsequent testing, then 9 6 hour duration tests should be reinstated. The major purpose of WET controls is to detect and eliminate toxicity in those cases where its presence is unknown or caused by interaction between otherwise innocuous substances. It must be emphasized that if WET is demonstrated, and it is established that it is due to a known toxicant, as allowed in 40 CFR 122.44 (d)(1)(v), the toxicant must be controlled by WET limits, specific numerical limits, or by both methods. If the permit issuing authority feels that the toxicant in question is, or will be, in compliance with existing water quality standards, WET testing or sampling procedures may be modified or, in very unusual cases, the effluent limit may be modified provided it can be shown that such actions are still sufficient to attain and maintain applicable numeric and narrative water quality standards. This will assure that the main purpose of the test does not continue to be masked by the known toxicant. As an example, if it is established that whole effluent toxicity is caused by a metal, and the discharger is on an acceptable compliance schedule to reduce its metal levels, the whole effluent protocol could be modified by the permit issuing authority simply by allowing the use of EDTA in the interim. Although this modification may mask some other toxicant, the test will still adhere more closely to its basic intent than it otherwise would. The most common example of test modification is the use of the C02 test which is now in the Appendix B protocols. It should be emphasized that this is the preferred way to control "creeping pH" during the tests, and that the use of more radical procedures, such as acid addition or zeolite treatment, has not been found to be necessary. If pH control is necessary, the value that is selected to cap the test must reflect the pH value of the receiving body of water or a value that represents the combination of effluent and receiving water. During the test the pH would be allowed to reach this level and then maintained. There is a program available to calculate this pH value. It requires the following information for the effluent and the receiving water: flow, alkalinity, and pH. The information should represent most of the range of values present in the receiving waters. 5 ------- Storm water permittees do not need to follow the block diagrams. Test protocols are in Appendix B. II. Numerical Limits: Compliance with whole effluent toxicity limits does not necessarily exclude the imposition of additional numerical limits on specific pollutants when appropriate. These limits may be based on numerical water quality standards if they exist; 304 (a) human health and/or aquatic life criteria (see EPA 440/5-86-001, "the gold book" or its successor); drinking water maximum concentration levels (MCLs), or a combination of all three as circumstances warrant. Concerning toxic pollutants such as metals; in order to supplant acute whole effluent limits numerical limitations must be based, as a minimum, on acute aquatic criteria, and applicable at the end of pipe unless a diffuser is present. 6 ------- REGION VIII WHOLE EFFLUENT TOXIC CONTROL PROGRAM COLORADO (1) RECEIVING WATER LOW FLOW DILUTION GREATER THAN 9.1, DISCHARGE IS INTERMITTENT, OR TO A CLASS 2 STREAM W/O NUMERIC AQUATIC STANDARDS ACUTE AN D/OR CHRONIC TESTS DISCHARGE EXCEEDS 20 MGD FOR A POTW OR 10 MGD FOR AN INDUSTRY MULTI DILUTIC )N ACUTE TESTS DISCHARGE EXCEEDS 20 MGD FOR A POTW OR 10 MGD FOR AN INDUSTRY NO YES NO YES QUARTERLY TESTING MONTHLY TESTING NO TOXICITY FOR TWELVE CONSECUTIVE MONTHS QUARTERLY TESTING MONTHLY TESTING NO TOXICITY FOR TWELVE CONSECUTIVE MONTHS YES NO YES NO REDUCE TESTING CONDUCT A TRE; CONTINUE TESTING REDUCE TESTING TO ONE SPECIES CONDUCT A TRE; CONTINUE TESTING UP TO 3 YEARS AFTER ISSUANCE APPLY AN EFFLUENT LIMIT OF NO ACUTE OR CHRONIC TOXICITY (2) UP TO THREE YEARS AFTER PERMIT ISSUANCE, APPLY AN EFFLUENT LIMIT OF NO ACUTE TOXICITY (1) APPLICABLE TO ALL MAJORS AND SIGNIFICANT MINOR PERMITS EXCEPT THOSE WITH NO REASONABLE POTENTIAL TO DISCHARGE TOXICANTS. MAJOR DISCHARGERS WITH NO REASONABLE POTENTIAL MUST CONTAIN WET MONITORING AND REOPENER LANGUAGE IN THEIR PERMITS. m-TF CHRONIC TOXICITY LIMITS ARE USED, CONDUCT CHRONIC TESTING UNLESS THE IN-STREAM DILUTION EATER THAN 4:1; IF GREATER THAN 4:1 (<20% EFFLUENT), ALSO PROHIBIT ACUTE TOXICITY IN 100% ENT. IF CHRONIC LIMITS ARE NOT USED, REQUIRE MULTI DILUTION ACUTE TESTS AND TWICE A YEAR SIC TESTS. SEE EXAMPLE LANGUAGE IN APPENDIX A. 7 ------- REGION VIII WHOLE EFFLUENT TOXIC CONTROL PROGRAM MONTANA (1) (1) APPLICABLE TO ALL MAJORS AND SIGNIFICANT MINOR PERMITS EXCEPT THOSE WITH NO REASONABLE POTENTIAL TO DISCHARGE TOXICANTS. MAJOR DISCHARGERS WITH NO REASONABLE POTENTIAL MUST CONTAIN WET MONITORING AND REOPENER LANGUAGE IN THEIR PERMITS. (2) IF CHRONIC TOXICITY LIMITS ARE USED, CONDUCT CHRONIC TESTING UNLESS THE IN-STREAM DILUT| IS GREATER THAN 4:1; IF GREATER THAN 4:1 (<20% EFFLUENT), ALSO PROHIBIT ACUTE TOXICITY IN lu EFFLUENT. IF CHRONIC LIMITS ARE NOT USED, REQUIRE ACUTE TESTS AND TWICE A YEAR CHRONIC TESTS. SEE EXAMPLE LANGUAGE IN APPENDIX A. 8 ------- REGION VIII WHOLE EFFLUENT TOXIC CONTROL PROGRAM NORTH DAKOTA (1) RECEIVING WATER LOW FLOW DILUTION GREATER THAN 10:1, DISCHARGE IS INTERMITTENT YES ACUTE A ND/OR CHRONIC TESTS DISCHARGE EXCEEDS 20 MGD FOR A POTW OR 10 MGD FOR AN INDUSTRY MULTI DILUTION ACUTE TESTS DISCHARGE EXCEEDS 20 MGD FOR A POTW OR 10 MGD FOR AN INDUSTRY NO YES NO YES QUARTERLY TESTING MONTHLY TESTING QUARTERLY TESTING MONTHLY TESTING NO TOXICITY FOR TWELVE CONSECUTIVE MONTHS NO TOXICITY FOR TWELVE CONSECUTIVE MONTHS YES NO YES NO REDUCE TESTING CONDUCT A TRE; CONTINUE TESTING REDUCE TESTING TO ONE SPECIES CONDUCT A TRE; CONTINUE TESTING UP TO 3 YEARS AFTER ISSUANCE, APPLY AN EFFLUENT LIMIT OF NO ACUTE OR CHRONIC TOXICITY (2) UP TO THREE AFTER PERMIT ISSUANCE, APPLY AN EFFLUENT LIMIT OF NO ACUTE TOXICITY (1) APPLICABLE TO ALL MAJORS AND SIGNIFICANT MINOR PERMITS EXCEPT THOSE WITH NO REASONABLE PC? TAL TO DISCHARGE TOXICANTS. MAJOR DISCHARGERS WITH NO REASONABLE POTENTIAL MUST CONTAIN V "STORING AND REOPENER LANGUAGE IN THEIR PERMITS. (2) IF CHRONIC TOXICITY LIMITS ARE USED, CONDUCT CHRONIC TESTING UNLESS THE IN-STREAM DILUTION IS GREATER THAN 4:1; IF GREATER THAN 4:1 (<20% EFFLUENT), ALSO PROHIBIT ACUTE TOXICITY IN 100% EFFLUENT. IF CHRONIC LIMITS ARE NOT USED, REQUIRE ACUTE TESTS AND TWICE A YEAR CHRONIC TESTS. SEE EXAMPLE LANGUAGE IN APPENDIX A. 9 ------- REGION VIII WHOLE EFFLUENT TOXIC CONTROL PROGRAM SOUTH DAKOTA (1) RECEIVING WATER LOW FLOW DILUTION GREATER THAN 10:1, DISCHARGE IS INTERMITTENT, OR TO A CLASS 9 OR 10 STREAM YES ACUTE A lND/OR CHRONIC TESTS | DISCHARGE EXCEEDS 2 0 MGD FOR A POTW OR 10 MGD FOR AN INDUSTRY MULTI DILUTION ACUTE TESTS DISCHARGE EXCEEDS 20 MGD FOR A POTW OR 10 MGD FOR AN INDUSTRY NO YES NO YES QUARTERLY TESTING MONTHLY TESTING QUARTERLY TESTING MONTHLY TESTING NO TOXICITY FOR TWELVE CONSECUTIVE MONTHS NO TOXICITY FOR TWELVE CONSECUTIVE MONTHS YES NO YES NO REDUCE TESTING CONDUCT A TRE; CONTINUE TESTING REDUCE TESTING TO ONE SPECIES CONDUCT A TRE; CONTINUE TESTING UP TO 3 YEARS AFTER ISSUANCE, APPLY AN EFFLUENT LIMIT OF NO ACUTE OR CHRONIC TOXICITY (2) UP TO THREE YEARS AFTER PERMIT ISSUANCE, APPLY AN EFFLUENT LIMIT OF NO ACUTE TOXICITY (1) APPLICABLE TO ALL MAJORS AND SIGNIFICANT MINOR PERMITS EXCEPT THOSE WITH NO REASONABLE POTENTIAL TO DISCHARGE TOXICANTS. MAJOR DISCHARGERS WITH NO REASONABLE POTENTIAL MUST CONTAIN WET MONITORING AND REOPENER LANGUAGE IN THEIR PERMITS. (2) IF CHRONIC TOXICITY LIMITS ARE USED, CONDUCT CHRONIC TESTING UNLESS THE IN-STREAM DILUH IS GREATER THAN 4:1; IF GREATER THAN 4:1 (<20% EFFLUENT), ALSO PROHIBIT.ACUTE TOXICITY IN 1^ EFFLUENT. IF CHRONIC LIMITS ARE NOT USED, REQUIRE ACUTE TESTS AND TWICE A YEAR CHRONIC TESTS. SEE EXAMPLE LANGUAGE IN APPENDIX A. 10 ------- REGION VIII WHOLE EFFLUENT TOXIC CONTROL PROGRAM UTAH (1) (1) APPLICABLE TO ALL MAJORS AND SIGNIFICANT MINOR PERMITS EXCEPT THOSE WITH NO REASONABLE Pfi ~ TIAL TO DISCHARGE TOXICANTS. MAJOR DISCHARGERS WITH NO REASONABLE POTENTIAL MUST CONTAIN Vi JNITORING AND REOPENER LANGUAGE IN THEIR PERMITS. (2) IF CHRONIC TOXICITY LIMITS ARE USED, CONDUCT CHRONIC TESTING UNLESS THE IN-STREAM DILUTION IS GREATER THAN 4:1; IF GREATER THAN 4:1 (<20% EFFLUENT), ALSO PROHIBIT ACUTE TOXICITY IN 100% EFFLUENT. IF CHRONIC LIMITS ARE NOT USED, REQUIRE ACUTE TESTS AND TWICE A YEAR CHRONIC TESTS. SEE EXAMPLE LANGUAGE IN APPENDIX A. 11 ------- REGION VIII WHOLE EFFLUENT TOXIC CONTROL PROGRAM WYOMING (1) RECEIVING WATER LOW FLOW DILUTION GREATER THAN 10:1, DISCHARGE IS INTERMITTENT, OR TO A CLASS IV STREAM ACUTE A >ND/OR CHRONIC TESTS | DISCHARGE EXCEEDS 20 .MGD FOR A POTW OR 10 MGD FOR AN INDUSTRY MULT I DILUTIC )N ACUTE TESTS DISCHARGE EXCEEDS 2 0 MGD FOR A POTW OR 10 MGD FOR AN INDUSTRY NO YES NO YES QUARTERLY TESTING MONTHLY TESTING QUARTERLY TESTING MONTHLY TESTING NO TOXICITY FOR TWELVE CONSECUTIVE MONTHS NO TOXICITY FOR TWELVE CONSECUTIVE MONTHS YES NO YES NO REDUCE TESTING CONDUCT A TRE; CONTINUE TESTING REDUCE TESTING TO ONE SPECIES CONDUCT A TRE; CONTINUE TESTING UP TO THREE YEARS AFTER ISSUANCE APPLY AN EFFLUENT LIMIT OF NO ACUTE OR CHRONIC TOXICITY (2) UP TO THREE YEARS AFTER PERMIT ISSUANCE, APPLY AN EFFLUENT LIMIT OF NO ACUTE TOXICITY (1) APPLICABLE TO ALL MAJORS AND SIGNIFICANT MINOR PERMITS EXCEPT THOSE WITH NO REASONABLE POTENTIAL TO DISCHARGE TOXICANTS. MAJOR DISCHARGERS WITH NO REASONABLE POTENTIAL MUST CONTAIN WET MONITORING AND REOPENER LANGUAGE IN THEIR PERMITS. (2)IF CHRONIC TOXICITY LIMITS ARE USED, CONDUCT CHRONIC TESTING UNLESS THE IN-STREAM DILUTION- IS GREATER THAN 4:1; IF GREATER THAN 4:1 (<20% EFFLUENT), ALSO PROHIBIT ACUTE TOXICITY IN l| EFFLUENT. IF CHRONIC LIMITS ARE NOT USED, REQUIRE ACUTE TESTS AND TWICE A YEAR CHRONIC TES" SEE EXAMPLE LANGUAGE IN APPENDIX A. 12 ------- TOXICITY REDUCTION EVALUATIONS Actual procedures to be followed in a TRE are unique in every individual situation. In addition, the discharger will always be more familiar with his operation than the regulatory agency and an excessive amount of procedural detail may inhibit an innovative approach. In any event, a TRE in most cases should pursue the following elements, most of which are self-evident. If a problem is established, and if prior knowledge or intuition is not helpful, initial efforts should be expended on characterization and identification of the toxicant(s). Procedures exist for rapidly narrowing the possibilities to certain groups of pollutants such as metals, non polar organics, oxidants, etc. In many cases, it is anticipated that the TRE may essentially terminate at this point if it is conclusively shown that the problem is due to one distinct pollutant whose source, and method of correction, is known. This pollutant may be already controlled through a compliance schedule linked to a numerical limit. Alternatively, a numerical limit and/or compliance schedule may be subsequently imposed on the permittee. Once the problem has been identified and located, the ultimate objective is elimination by process controls, pretreatment, combined waste stream treatment, local enforcement, or whatever other measure may be necessary. It is anticipated that toxicity problems will be controlled in most cases by following the above procedures. However, as noted earlier, there may be situations when a well done and acceptable TRE will reveal a problem requiring additional time consuming activity before final resolution. Under these circumstances, relief may be granted through the language noted in Appendix A. It is emphasized that, under these circumstances, the discharger must convince the regulatory agency that a thorough TRE has been done and more time is needed to address the problem. Only then should permit relief be granted. EPA has developed guidance on TIE/TRE procedures (6) (7) (8) (9). This information has been widely distributed, and is available from the Region VIII EPA Office or from National Center for Environmental Publications and Information, PO Box 42419, Cincinnati, OH 45242. 13 ------- BIBLIOGRAPHY 1. "Technical Support Document for Water Quality Based Toxics Control", EPA 505/2-90-001, U.S. EPA, March, 1991. 2. "Methods for Measuring Acute Toxicity of Effluent and Receiving Waters to Freshwater and Marine Organisms," Fourth Edition EPA 600/4-90/027F, U.S. EPA, August 1993. 3. "Short Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, Third Edition", EPA 600/4-91/002, U.S. EPA, July 1994. 4. "Permit Writers Guide to Water Quality Based Permitting for Toxic Pollutants", Office of Water, U.S. EPA, 1987. 5. "Development of Water Quality-based Permit Limitations for Toxic Pollutants; National Policy", U.S. EPA Federal Registerf Vol. 49, No. 48, March 9, 1984. 6. "Methods for Aquatic Toxicity Identification Evaluations, Phase I Toxicity Characterization Procedures",Second Edition, EPA/600/6-91/003, February 1991. 7. "Methods for Aquatic Toxicity Identification Evaluations, Phase II Toxicity Identification Procedures for Samples Exhibiting Acute and Chronic Toxicity", EPA/600/R-92/080, September, 1993. 8. "Methods for Aquatic Toxicity Identification Evaluations, Phase III Toxicity Confirmation Procedures for Samples Exhibiting Acute and Chronic Toxicity", EPA/600/R-92-/081, September, 1993. 9. "Toxicity Identification Evaluation: Characterization of Chronically Toxic Effluents, Phase I", EPA 600/6-91/005F, May, 1992. 10. Whole Effluent Toxicity: Guidelines Establishing Test Procedures for the Analysis of Pollutants. Federal Register. Vol. 60. No. 199, October 16, 1995. 11. Whole Effluent Toxicity (WET) Control Policy, EPA 833-B-94-002, July 1994. 14 ------- APPENDIX A EXAMPLE PERMIT LANGUAGE 15 ------- A. Definitions (Continued) 13. "Acute Toxicity" occurs when 50 percent or more mortality is observed for either species (See Part I.C.) at any effluent concentration. Mortality in the control must simultaneously be 10 percent or less for the effluent results to be considered valid. 14. "Chronic toxicity" occurs when during a chronic toxicity test, the 25% inhibition concentration (IC25) calculated on the basis of test organism survival and growth, or survival and reproduction, is less than or equal to the effluent dilution designated in this permit ( see Part I.C.) 15. "IC2511 (Inhibition concentration) is a point estimate of the toxicant concentration that would cause a 25% reduction in a nonlethal biological measurement of the test organism, such as reproduction or growth. 16. "NOEC" (no observer effect concentration) is the highest tested concentration of an effluent or a toxicant at which no adverse effects are observed on the aquatic test organism at a specific time of observation. Determined using hypothesis testing. ------- USE THIS PAGE WHEN ONLY ACUTE TOXICITY IS LIMITED C. Specific Limitations and Self-Monitoring Requirements 3. Whole Effluent Toxicity Testing - Acute Toxicity Starting in the quarter of calendar year , the permittee shall, at least once each calendar quarter, conduct acute static replacement toxicity tests on a sample of the discharge. Quarterly samples shall be collected on a two day progression; i.e., if the first quarterly sample is on a Monday, during the next quarter, sampling shall be on a Wednesday, etc. The replacement static toxicity tests shall be conducted in accordance with the procedures set out in the latest revision of "Methods for Measuring the Acute Toxicity of Effluents to Freshwater and Marine Organisms", EPA-600/4-90/027F (Rev. August 1993)and the "Region VIII EPA NPDES Acute Test Conditions -Static Renewal Whole Effluent Toxicity Test". In the case of conflicts, the Region VIII Document will prevail. The permittee shall conduct an acute 48-hour static toxicity test using Ceriodaphnia dubia and an acute 96 hour static toxicity test using Pimephales promelas. Acute toxicity occurs when 50 percent or more mortality is observed for either species at any effluent concentration. If more than 10 percent control mortality occurs, the test shall be repeated until satisfactory control survival is achieved. If acute toxicity occurs, an additional test shall be conducted within two weeks of the date of when the permittee learned of the test failure. If only one species fails, retesting may be limited to this species. Should acute toxicity occur in the second test, testing shall occur once a month until further notified by the permit issuing authority. Quarterly test results shall be reported along with the Discharge Monitoring Report (DMR) submitted for the end of the reporting calendar quarter (e.g., whole effluent results for the calendar quarter ending March 31 shall be reported with the DMR due April 28, with the remaining reports submitted with DMRs due each July 28, October 28, and January 28). Monthly test results shall be reported along with the DMR submitted for that month. The format for the report shall be consistent with the latest revision of the "Region VIII Guidance for Acute Whole Effluent Reporting", and shall include all chemical and physical data as specified. If the results for four consecutive quarters of testing indicate no acute toxicity, the permittee may request the permit issuing authority to allow a reduction to quarterly acute toxicity testing on only one species on an alternating basis. The permit issuing authority may approve or deny the ------- request based on the results and other available information without an additional public notice. If the request is approved, the test procedures are to be the same as specified above for the test species. ------- USE THIS PAGE (AND THE PRECEDING PAGE) WHEN ONLY ACUTE TOXICITY IS LIMITED BUT TWICE A YEAR CHRONIC TESTING IS ALSO REQUIRED C. Specific Limitations and Self-Monitoring Requirements 4. Whole Effluent Toxicity Testing - Chronic Toxicity Starting , the permittee shall, at least once during the six month period from January through June, and at least once during the six month period from July through December, conduct chronic short term toxicity tests on a sample of the final effluent. If only two samples are taken, the interval between samples shall be at least three months. The chronic toxicity tests shall be conducted in accordance with the procedures set out in the latest revision of "Short Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms", EPA/600/4- 91/002, and the "Region VIII EPA NPDES Chronic Test Conditions - Static Renewal Whole Effluent Toxicity Test". In case of conflicts, the Region VIII procedure will prevail. Test species shall consist of Ceriodaphnia dubia and Pimephales promelas. If acceptable control performance criteria are not met, the test shall be considered invalid. Chronic toxicity occurs when during a chronic toxicity test, the 25% inhibition concentration (IC25) calculated on the basis of test organism survival and growth or survival and reproduction, is less than or equal to effluent dilution. Test results shall be reported with the Discharge Monitoring Report (DMR) submitted for the end of the calendar period during which the whole effluent test was run (e.g. results shall be reported with the next routine DMR covering the month in which the sample was taken). The format for the report shall be consistent with the latest revision of the "Region VIII Guidance for Chronic Whole Effluent Reporting", and shall include all the physical and chemical testing as specified. If the results for four consecutive samples of chronic whole effluent testing indicate no chronic toxicity, the permittee may request the permit issuing authority to allow the permittee to reduce testing frequency, and/or reduce testing to one species on an alternating basis, and/or modify testing to the acute test program. The permit issuing authority may approve, partially approve, or deny the request based on results and other available information. If approval is given, the modification will take place without a public notice. ------- USE THIS PAGE WHEN CHRONIC TOXICITY IS LIMITED C. Specific Limitations and Self-Monitoring Requirements 3. Whole Effluent Toxicity Testing - Chronic Toxicity Starting in the 1__ quarter of calendar year , the permittee shall, at least once each quarter, conduct chronic short term toxicity tests on the final effluent. There shall not be chronic toxicity in percent concentration of the final effluent. The monitoring frequency shall be quarterly. Quarterly samples shall be collected on a two day progression; i.e., if the first quarterly sample is on a Monday, during the next quarter, the sampling shall begin on a Wednesday. If chronic toxicity is detected, an additional test shall be conducted within two weeks of the date of when the permittee learned of the test failure. The need for any additional samples shall be determined by the permit issuing authority. The chronic toxicity tests shall be conducted in accordance with the procedures set out in the latest revision of "Short Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms", EPA/600/4- 91/002, and the "Region VIII EPA NPDES Chronic Test Conditions - Static Renewal Whole Effluent Toxicity Test". In case of conflicts, the Region VIII procedure will prevail. Test species shall consist of Ceriodaphnia dubia and Pimephales promelas. A multi dilution test consisting of five concentrations and a control is required. If test acceptability criteria is not met for control survival, growth, or reproduction, the test shall be considered invalid. Chronic toxicity occurs when, during a chronic toxicity test, the 25% inhibition concentration (IC25) calculated on the basis of test organism survival and growth or survival and reproduction, is less than or equal to effluent concentration. Test results shall be reported along with the Discharge Monitoring Report (DMR) submitted for the end of the calendar period during which the whole effluent test was run (e.g. results for the calendar quarter ending March 31 shall be reported with the DMR due April 28, with the remaining reports submitted with DMRs due each July 28, October 28, and January 28). Monthly test results shall be reported along with the DMR submitted for that month. The format for the report shall be consistent with the latest revision of the "Region VIII Guidance for Chronic Whole Effluent Reporting", and shall include all the physical and chemical testing as specified. If the results for one year (four consecutive quarters) of whole effluent testing indicate no chronic toxicity, the permittee may request the permit issuing authority to allow ------- the permittee to reduce testing frequency, and/or reduce testing to one species on an alternating basis, and/or modify testing to the acute test program. The permit issuing authority may approve, partially approve, or deny the request based on results and other available information. If approval is given, the modification will take place without a public notice. ------- USE THIS PAGE (AND THE APPROPRIATE PRECEDING PAGE) IF BOTH ACUTE TOXICITY AND CHRONIC TOXICITY ARE LIMITED C. Specific Limitations and Self-Monitoring Requirements 4. Whole Effluent Toxicity Testing - Acute Toxicity Starting in , the permittee shall conduct quarterly acute static replacement toxicity tests on a effluent sample of the discharge. The effluent shall be obtained from the sample required for the chronic toxicity tests as noted in Part of this permit. The replacement static acute toxicity tests shall be conducted in accordance with the procedures set out in the latest revision of "Methods of Measuring the Acute Toxicity of Effluents to Freshwater and Marine Organisms", EPA-600/4- 90/027F (Rev. August 1993) and the "Region VIII EPA NPDES Acute Test Conditions - Static Renewal Whole Effluent Toxicity Test." In the case of conflicts, the Region VIII procedures will prevail. The permittee shall conduct the acute 48-hour static toxicity test using Ceriodaphnia dubia, and the acute 96 hour static toxicity test using Pimephales promelas. Acute toxicity occurs when 50 percent or more mortality is observed for either species at any effluent concentration. If more than 10% control mortality occurs, the test shall be repeated until satisfactory control survival is achieved. If acute toxicity occurs, an additional test shall be conducted within two weeks of the date of when the permittee learned of the test failure. If only one species fails, retesting may be limited to this species. Should toxicity occur in the second test, testing shall occur once a month until further notified by the permit issuing authority. Quarterly test results,shall be reported along with the Discharge Monitoring Report (DMR) submitted for the end of the reporting calendar quarter (e.g., whole effluent results for the calendar quarter ending March 31 shall be reported with the DMR due April 28, with the remaining reports submitted with DMRs due each July 28, October 28, and January 28). Monthly test results shall be reported along with the DMR submitted for that month. The format for the report shall be consistent with the latest revision of the "Region VIII Guidance for Acute Whole Effluent Reporting", and shall include all chemical and physical data as specified. If the results for four consecutive quarters of testing indicate no acute toxicity, the permittee may request the permit issuing authority to allow a reduction to quarterly acute toxicity testing on only one species on a alternating basis. The permit issuing authority may approve or deny the request based on the results and other available information ------- without an additional public notice. If the request is approved, the test procedures are to be the same as specified above for the test species. ------- C. Specific Limitations and Self-Monitoring Requirements 5. Toxicity Reduction Evaluation (TRE) Toxicity Identification Evaluation (TIE) Should acute toxicity and/or chronic toxicity be detected in the permittee's discharge, a TIE-TRE shall be undertaken by the permittee to establish the cause of the toxicity, locate the source(s) of the toxicity, and develop control of, or treatment for the toxicity. Failure to initiate, or conduct an adequate TIE-TRE, or delays in the conduct of such tests, shall not be considered a justification for noncompliance with the whole effluent toxicity limits contained in Part I.C.l. of this permit. A TRE plan needs to be submitted to the permitting authority within 45 days after confirmation of the continuance of effluent toxicity. 6. Chronic Toxicity Limitation-Reopener Provision This permit may be reopened and modified (following proper administrative procedures) to include chronic whole effluent toxicity limitations if any other information or data are developed indicating that chronic whole effluent toxicity limits are needed as required under 40 CFR 122.44 (d). Also see Part IV.P. of this permit for additional whole effluent toxicity reopener provisions. If acceptable to the permit issuing authority, and if in conformance with current regulations, this permit may be reopened and modified to incorporate TRE conclusions relating to additional numerical limitations, a modified compliance schedule, and or modified whole effluent protocol. ------- USE THIS LANGUAGE WHEN A TOXICITY LIMIT IS IN THE PERMIT Specific Limitations and Self-Monitoring Requirements Toxicity Limitation-Reopener Provision. This permit may be reopened and modified (following proper administrative procedures) to include a new compliance date, additional or modified numerical limitations, a new or different compliance schedule, a change in the whole effluent protocol, or any other conditions related to the control of toxicants if one or more of the following events occur: a. Toxicity was detected late in the life of the permit near or past the deadline for. compliance. b. The TRE results indicate that compliance with the toxic limits will require an implementation schedule past' the date for compliance and the permit issuing authority agrees with the conclusion. c. The TRE results indicate that the toxicant(s) represent pollutant(s) that may be controlled with specific numerical limits, and the permit issuing authority agrees that numerical controls are the most appropriate course of action. d. Following the implementation of numerical controls on toxicants, the permit issuing authority agrees that a modified whole effluent protocol is necessary to compensate for those toxicants that are controlled numerically. e. The TRE reveals other unique conditions or characteristics which, in the opinion of the permit issuing authority, justify the incorporation of unanticipated special conditions in the permit. USE THIS LANGUAGE WHEN WHOLE EFFLUENT TOXICITY MONITORING IS IN THE PERMIT BUT A WHOLE EFFLUENT TOXICITY LIMIT IS NOT IN THE PERMIT Specific Limitations and Self-Monitoring Requirements Toxicity Limitation-Reopener Provision This permit may be reopened and modified (following proper administrative procedures) to include whole effluent toxicity limitations if whole effluent toxicity is detected in the discharge. ------- APPENDIX B REGION VIII ACUTE AND CHRONIC TESTING PROTOCOLS ------- REGION VIII EPA NPDES ACUTE TEST CONDITIONS STATIC RENEWAL WHOLE EFFLUENT TOXICITY TEST 1. Temperature 2 . Light duration and type 3. Container size 4. Volume of test solution 5. Age of test organisms 6. No. of organisms per container 7. No. of replicates 8. Renewal frequency 9. No. of dilutions Ceriodaphnia dubia 20° c ± 1° 16 hours-ambient 30 ml minimum 15 ml minimum less than 24 hr 5 4 daily 5 (+control) Pimephales promelas (Fathead minnows) 20° c ± 1° 16 hours-ambient 250 ml minimum 200 ml minimum 1 to 14 days (a) 10 2 (minimum) daily 5 (+control) 10. Feeding 11. Test duration 12 . Acceptable control mortality none 4 8 hours 10 % or less 0.1 ml brine shrimp prior to selection, and at 48 hrs (if necessary) 9 6 hours (b) 10% or less 13. Dilution Series: 100%, 75%, 50%, 25%, 12.5%, 6.25%, 0% (control). 14. Dilution water: Dilution water shall consist of receiving water if it is not toxic. If receiving water is unsuitable, use moderately hard reconstituted water. 15. Holding time: A maximum of 36 hours from the conclusion of sampling until the initiation of testing. Samples must be maintained at 4°C or less. Do not freeze samples. 16. C02 atmospheres: Permittees may receive individual case by case permission to introduce C02 enriched atmospheres if necessary to inhibit "rising pH creep". Target pH must reflect receiving water and effluent values. pH shall not be allowed to fall more than 0.2 units below the target value. (a) All fish used in a test series must be born within 24 hours of each other. (b) If previous testing has shown greater than 20% mortality at 96 hours and not at 48 hours, test duration should be 96 hours. Once the 48 hour testing has been authorized, if >20% mortality occurs in subsequent testing, then 96 hour duration tests should be reinstated. ------- REGION VIII EPA NPDES CHRONIC TEST CONDITIONS STATIC RENEWAL WHOLE EFFLUENT TOXICITY TEST Ceriodaphnia dubia Pimephales promelas (Fathead minnows) 1. Temperature 2. Light duration and Type 3. Test container Size 4. Test solution volume 5. Age of test organisms 6. No. of organisms per container 7. No. of replicates 8. Renewal frequency 9. No. Of Dilutions 10 Feeding 11. Test duration 12. Acceptable control Performance: 25° C ± 1° 16 hours-ambient 30 ml (minimum) 15 ml (minimum) less than 24 hr (a) 1 10 daily (c) 5 (+ control) (d) until 60% have 3 broods in the control 20% mortality or less; three brood average total of 15 or more. 25° C ± 1° 16 hours-ambient 500 ml (minimum) 250 ml (minimum) less than 24 hr(b) 10 (minimum) 4 (minimum) daily (c) 5 (+ control) (e) 7 days 20% mortality or less; avg. dry weight gain per fish = 0.25 mg or more. 13. Dilution Series: 100%, 50%, 25%, 12.5%, 6.25%, 0% (control). 14. Dilution Water: Dilution water shall consist of receiving water if not toxic. If receiving water is unsuitable, use moderately hard reconstituted water. 15. Holding time: A maximum of 36 hours from the conclusion of sampling until the initiation of testing should be maintained. Samples must be maintained at 4°C or less Do not freeze. (a) Ceriodaphnia used in a test series must be born within 8 hrs of each other. (b) If fish are shipped in, they must be less than 48 hours old. (c) Permittee shall use a minimum of three fresh effluent samples taken at intervals of two or three days depending on weekend shipping arrangements. (d) Recommendation: 0.1 ml/day of "YCT" and up to 0.1 ml/day of Selenastrum suspension containing 3-4 x 107 cells. (e) 0.1 ml of brine shrimp three times a day at four hour intervals or longer, or 0.15 ml twice a day at a six hour interval or longer. ------- 1. 2 . 3 . 4 . 5 . 6. 7 . 8 . 9 . 10 12 13 14 15 RgGION VIII NPDES CHRONIC TEST CONDITIONS STATIC WHOLE EFFLUENT TOXICITY TESTS Selenastrum capricornuturn Temperature Light quality 25 ± 1° "Cool white" florescent lighting Light intensity Test container Size Test solution volume Age of test organisms Initial cell density in test containers No. of replicates Renewal frequency Shaking rate Test duration Acceptable control performance 400 ± 40 foot candles or 4306 lux 125 ml or 250 ml 50 or 100 ml 4 to 7 days 10,000 cells/ml 4 none 100 cpm continuous, or twice daily by hand 96 hours 2 x 105 cells/ml without EDTA or 1 x 106 cells/ml with EDTA, Variability of controls should not exceed 20% Dilution Series: 100%, 50%, 25%, 12.5%, 6.25%, 0% (control). Dilution water: Algal stock culture medium with and/or without EDTA. Holding time: A maximum of 36 hours from the end of sampling until the initiation of testing should be maintained. Samples must be maintained at 4°C or less. Do not freeze. ------- APPENDIX C ACUTE AND CHRONIC REPORTING GUIDANCE ------- REGION VIII GUIDANCE FOR ACUTE WHOLE EFFLUENT REPORTING BPMIT NAME NPDES No OUTFALL NO. MORTALITY TEST: PASS FAIL LC50 % Tua Test Species Sample Time & Date Sample temperature upon arrival at laboratory: Analysis Time & Date: Begin End Dilution water used: Initial Total Residual Cl2 in 100% Effluent: Initial NH3 (as N) in 100% Effluent: pH in 100% Effluent: Initial After 24 Hours: pH in 0% Control: Initial After 24 Hours: Dilutions (% Effluent) * NUMBER ALIVE 0% 6.25% 12 .5% 25% 50% 75% 100% Start of test After 24 hrs After 48 hrs After 72 hrs After 96 hrs * normally, a minimum of five plus control (0%) COMMENTS: ANALYST'S NAME LABORATORY SIGNATURE/DATE ------- REGION VIII GUIDANCE FOR CHRONIC WHOLE EFFLUENT REPORTING CERIODAPHNIA DUBIA PERMIT NAME NPDES No OUTFALL NO. IC25 NOEC PASS FAIL Tuc Sample Time, & Dates Analyses: Time & Date No 1 Beginning No 2 Ending No 3 Sample temperature upon arrival at laboratory Dilution Water Used: Initial NH3(as N) in 100% Effluent Initial TRC in 100% Effluent Initial pH in 100% Effluent pH after 24 hours Initial pH in Control pH after 24 hours CERIODAPHNIA Total Number of Young per Adult % Dilution 6 .25 12 .5 2R 50 ino Replicate A B C D E F 6 H I J MEAN No. Live Adults COMMENTS: ANALYST'S NAME LABORATORY SIGNATURE/DATE ------- REGION VIII GUIDANCE FOR CHRONIC WHOLE EFFLUENT REPORTING PIMEPHALES PROMELAS (FATHEAD MINNOW) PERMIT NAME IC25 NOEC PASS NPDES NO FAIL OUTFALL NO. Tu. Sample Time, & Dates No 1 No 2 No 3 Dilution Water Used: Analyses: Time & Date Beginning Ending Sample temperature upon arrival at laboratory- Initial NH3(as N)in 100% Effluent. Initial pH in 100% Effluent Initial pH in Control Initial TRC in 100% Effluent. pH after 24 hours pH after 24 hours. p-rmgpwaT.ES PROMELAS Mean Weight | Number of surviving organisms % Dilution Control 6 .25 12 .5 25 50 100 Replicates A 1 1 1 1 1 1 B 1 1 1 1 1 1 C 1 1 1 1 1 1 D 1 1 1 1 1 1 Mean 1 1 1 1 1 1 COMMENTS A] ST1 S NAME Lf ATORY SIGNATURE/DATE ------- REGION VIII GUIDANCE FOR CHRONIC WHOLE EFFLUENT REPORTING SELENASTRUM CAPRICORNUTUM PERMIT NAME NPDES No OUTFALL NO. IC25 NOEC PASS FAIL TUC Sample Time & Date Analyses: Time & Date No 1 Beginning Ending Sample temperature upon arrival at laboratory Dilution Water Used: Initial NH3(as N) in 100% Effluent Initial TRC in 100% Effluent Initial pH in 100% Effluent Initial pH in Control EDTA Used SELENASTRUM CAPRICORNUTUM Cell Density or Chlorophyll Content % Dilution Control 6 .25 12 .5 25 50 100 Replicate A B C D Mean COMMENTS: ANALYST'S NAME LABORATORY SIGNATURE/DATE ------- |