these waters, the quantity of effluent discharged has a strong effect on the instream dilution and therefore upon the RWC. At the extreme caseof astream that is100 percent effluent, it isthe effluent concentration rather than the effluent mass discharge that dictates the instream concentration. Therefore, EPA recommends that permit limits on both mass and concentration be specified for effluents discharging into waters with lessthan 100 fold dilution to ensure attainment of water quality standards.


## 5.7.2 EmugytZtmsmdon Water quality-based permit limits by themselves do not provide any incentive to dischargers to reduce wastewater flows. The reverse is true; a more dilute effluent means water quality-based limits are more easily achieved. However, increased flow translates into increased power consumption for treatment facilities. Significant power usage stems from pumping and mixing of volumes ofwastewater in treatment systems. If the volume of wastewater can be reduced, power consumption can be reduced and lessfossilfuel burned. Such reductions can be expected to result in concomitant decreases in air pollution.
Therefore, EPArecommends that flow reductions and energy savings be specifically encouraged where appropriate (usually in dilutions greater than 1OO:l) by allowing water quality-based permit limits to be mass-based and by allowing concentration-based limits to vary in accordance with flow reduction requirements. The permit also could include an energy savings analysis subject to approval by the permitting authority.



## 5.7.3 lZWsi&afions intbelkwof~icd-wlfk Umits Metals

Another common problem encountered in expressing permit limits occurs for metals. Some water quality standards express numeric criteria for metals in terms of the dissolved or acid soluble phase of the metal. NPDES regulations at 40 CFR122.45(c) require permit limitations for metals to be expressed in terms of total recoverable metal unless (1) an effluent guideline requires the use of another form, (2) technology-based limits are established on a case-by-case basis, or (3) the approved analytical method measures only the dissolved form.

Where State water quality standards are expressed directly astotal or total recoverable metals, the permit limit can be established directly. Where the water quality standards are expressed asdissolved or acid soluble metal, the permit writer will need to reconcile the different expressions of metals when establishing the permit limits. Some State water quality standards implementation policies or procedures provide the requirements for this conversion. In instances where a State has no policy or procedure, the permit writer can take one of four approaches. First, the permit writer could assume no difference between the dissolved or acid soluble phases and the total recoverable phase. This isthe most stringent approach and would be most appropriate in waters with low solids, where the discharged form of the metal was mostly inthe dissolved phase, orwhere data to usethe other options are unavailable. Second, the permit writer could develop a site-specific relationship between the phases of metals by developing arelationship through review of information on instream metal concentrations. This approach requires concurrent sampling of both metal phases during periods reflective of the environmental conditions used to determine the WL4. Third, the permit writer could usea relationship developed by EPAfrom national data; this relationship isdescribed inthe national guidance for determining WlAs for toxic metals in rivers. This relationship requires knowledge of instream concentrations oftotal suspended solids at the environmental conditions used to determine the WIA. Fourth, the permit writer could use a geochemical model, such as the equilibrium metal speciation model MINTEQA2 (see Chapter 4). However, the input data requirement of this model are equivalent to collecting site-specific data under Option 2. These options will be expressed in more detail in subsequent guidance issued by EPA.
Updute: TheAgency has issued “interim Guidance on Interpretotion and lmplementution Aquatic LifeCriteria for Metals. ” Seethe update notice infront of this document forovoilobility.

Detection Level Limits

A commonly encountered problem isthe expression of calculated limits for specific chemicals where the concentration of the limit isbelow the analytical detection level for the pollutant ofconcern. This isparticular’ true for pollutants that are toxic in extremely low concentrations or that bioaccumulate.

The recommended approach for these situations is to include in Part 1 of the permit the appropriate permit limit derived from the water quality model and the WLA for the parameter of concern, regardless of the proximity of the limit to the analytical detection level. The limit also should contain an accompanying requirement indicating the specific analytical method that should be used for purposes of compliance monitoring. The requirement should indicate that any sample is analyzed in accordance with the specified method and found to be below the compliance level will be deemed to be in compliance with the permit limit unless other monitoring information (asdiscussed below) indicates aviolation. Sample results reported at or above the compliance level should be reported asobserved whereas samples below the compliance level should be reported as lessthan this level.

The level of compliance cited in the permit must be clearly defined and quantifid. For most NPDES permitting situations, EPA recommends that the compliance level be defined in the permit asthe minimum level (ML). The ML is the level at which the entire analytical system gives recognizable mass spectra and acceptable calibration points. This level corresponds to the lowest point at which the calibration curve isdetermined based on analyses for the pollutant of concern in a reagent water. The ML has been applied in determinations of pollutant measurements by gas chromatography combined with mass spectrometry. The concept of a minimum level recently was used in developing the Organic Chemicals, Plastics, and Synthetic Fibers effluent guidelines 

## PI.

The minimum level is not equivalent to the method detection level, which is defined in 40 CFRPart 136 Appendix 6 asthe minimum concentration of a substance that can be measured and reported with 99-percent confidence that the analyte concentration isgreater than zero and isdetermined from the analysisof a sample in agiven matrix containing the analyte. EPAis not recommending use of the method detection level because quantitation at the method detection level isnot asprecise asat

111

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the ML. It isnot similar to the practical quantitation limit (PQL), which is typically set as a specific (and sometimes arbitrary) multiple of the method detection level. Because the PQL has no one definition, EPAisnot recommending itsusein NPDES permitting. Nor isit similar to other terms such asthe limit of detection, limit of quantitation, estimated quantitation limit, or instrument detection limit.

The permitting authority may choose to specify another level at which compliance determinations are made. Where the permitting authority sochooses, the authority must be assured that the level isquantifiable, defensible, and close aspossible to the permit level.

Where water quality-based limits below analytical detection levels are placed in permits, EPA recommends that special conditions also be included in the permit to help ensure that the limits are being met and that excursions above water quality standards are not occurring. Examples of such special conditions include fishtissue collection and analyses, limits and/or monitoring requirements on internal waste streams, and limits and/or monitoring for surrogate parameters. This information can be used to help support reopening the permit to establish more stringent effluent limits if necessary.



### 5.7.4 ConsMevatioaintheUseofwlroleEffhnt ToxMy lhifs Test Methods

NPDES regulations at 40 CFR122.44(i)(l)(iv) require that methods approved under 40 CFRPart 136 be used for compliance monitoring, and in the absence of an approved method, the permit must specijl the method to be used. The permit should alsocarefully consider any other case-specific aspects of the whole effluent toxicity test method that should be designated in the permit. Such aspects as the dilutions at which testing will be conducted, the different species to be used, the specific endpoints, the statistical procedures for analyzing the data, quality assurance, and other factors should be clearly stated asa permit condition to assure that the whole effluent toxicity testing that is performed to ascertain compliance with a limit or monitoring requirement isthe test procedure the regulatory authority desires. In some instances, promulgated methodologies allow significant flexibility and choice in how the method isactually conducted. A simple reference to the methodology in the permit may not result in the test being conducted asintended.

Units of Expression and Detection Levels

The permit limit for toxicity itself and the detection levels, or sensitivity levels, associated with the various types of toxicity tests determine the type of monitoring requirement, which should be specified with the limit. It is a misconception to think, for example, that only acute toxicity tests should be used where the WLA for acute protection is used to derive the more limiting LTA or should always be used to monitor for the MDL. It isa similar misconception to think that only chronic tests should be used where chronic LTAislimiting or should always be used to monitor for the average monthly limit. The MDLs and AMLs are derived from the more limiting ofthe two LTAs. Therefore, either acute or chronic tests might apply to a given situation depending upon the test detection levels or test sensitivity.

For example, a limit of 5 TU, (no observed effect concentration [NOEC] of 20 percent or greater) would require chronic toxicity testing where the ACR is20 for that effluent, An acute test would not be sensitive enough to measure effluent toxicity in this instance, since 5TU, would be equivalent to 0.25 TU,. Conversely, ifthe ACRwas 2, then an acute test could be used because 5TU, would be equal to 2.5 TUa. Generally, there isno reason to mix two types of monitoring requirements for the same limit when limits are derived from the most limiting LTA. Doing so will confuse the resultsand complicate assessments ofaverage monthly limits where sampling frequency isgreater than once per month.

The acute toxicity test, when using an LCso asthe test endpoint, has an upper sensitivity level of loo-percent effluent, or 1.OTU,. If lessthan 50 percent of the test organisms die at loo-percent effluent an LCso cannot be determined from the test data, and the true LCso value for the effluent cannot be measured. In this situation, an acute test could still be used for compliance monitoring purposes but the endpoint would need to be changed to a greater level of sensitivity. The endpoint could be specified in terms of “no statistically significant difference in acute toxicity between 100 percent effluent sample and the control.” This is the most sensitive application of an acute test and could be used for monitoring compliance with a limit that, because of lack of available dilution, applies the EPArecommended acute criterion of 0.3 TU, at the end of the pipe.
However, these tests would not accurately quantify any level of chronic toxicity present. For chronic testing, an effluent with an NOEC of greater than 100 percent presents asimilar test sensitivity problem. An effluent with an NOEC of greater than 100 percent contains less than 1.0 TU, and would meet the EPA recommended chronic criterion for toxicity at the edge of the mixing zone, ifdilution were available, aswell asat the end ofthe pipe if no dilution were available.
Description of Limits

When toxicity limits are used, additional description of the limit is required. The limit should be stated in Part 1as“effluent toxicity” in the parameter column with “maximum TUs,” “minimum ATE [acute toxicity endpoint],” or “minimum NOEC” in parentheses underneath. The numerical values should be placed in the appropriate concentration column followed by TU or apercent sign. A footnote should direct the reader to Part 3 for specific requirements on how to conduct the tests. The description in Part 3 should accomplish the following:

l Explain how the limit is expressed (e.g., the limit is the minimum ATE expressed as percent effluent or the limit is the maximum TU,)

l Specify the test species and the test methods for compliance monitoring purposes

l Describe any special reporting or followup requirements (e.g., requirements to conduct atoxicity reduction evaluation).

112

### - -~ --

The 

### language in Part 3should be modified as needed to suit the situation. The following example 

### language is provided only for purposes of illustration:

l “The effluent toxicity limit contained in Part 1 isthe allowable chronic toxicity to the most sensitive of three test species. 

### It isexpressed asthe allowable NOEC in percent effluent. The required test species and the procedures to follow are described in Short Term Methods for Estimating the Chronic Toxicity ofEffluentsand Receiving Watersto Freshwater Organisms, EPAf600/4-89/001, March 1989.”

l “The permittee shall conduct monitoring ofeffluent toxicity once per month. One 24-hour composite sample shall be collected and tested within 24 hours of collection. Results shall be reported asthe NOEC. Any test that does not meet quality control requirements as described in the above referenced methods shall be repeated using a freshly collected sample assoon aspracticable.”



### 57.5 sekction ofMoRiforillgfreguencles There is no fixed guidance on establishment of monitoring frequencies. The decision on the monitoring frequency is casespecific and needs to consider a number of factors, including those listed below:

l Type of treatment process, including retention time

l Environmental significance and nature of the pollutant or pollutant parameter

l Cost of monitoring relative to the discharger’s capabilities and benefit obtained

l Compliance history

l Number of monthly samples used in developing the permit limit

l Effluent variability.

Based upon an array of data analyzed for both individual chemicalsand whole effluent toxicity, and independent ofother considerations, EPAhas observed that ideally 10 or more samples per month provides the greatest statistical likelihood that the average ofthe various monthly values will approach the true monthly LTA value. In practice, however, selection of monitoring frequencies will need to consider the previously mentioned factors and arrive at a reasonable compromise of the appropriate considerations.

Permits require monitoring to establish whether a facility is discharging at a level that complies with the permit limits. All monitoring includes analytical variability. The true concentration in asample can be higher or lower than the measured one due to this variability; however, there is no way to predict which way it will go. Historically, EPAhas not directly considered analytical variability from monitoring methods when establishing permit limits. Ifthe upper bound of the analytical variability was added to the limit, there would be a higher potential that the permit limit would fail to protect the wasteload allocation. This would not be consistent with 40 CfR 122.44(d)(l). On the other hand, ifthe lower bound of the analytical uncertainty was subtracted from the limit, there would be better assurance that the limit achieved the WLA. This approach could be overly conservative given the other factors used to develop permit limits. EPAbelieves that its recommended approach provides a balance between these two extremes.



### 57.7 kMmksi~dhg CWA Section 402(o) establishes express statutory language prohibiting the relaxation of permit limits based on water quality. Under the statute, relaxation of water quality-based limits is permissible only if either the requirements of Sections 402(o)(2) or 303(d)(4) are met. These two provisions constitute independent exceptions to the prohibition against relaxation of permit limits. tf either ismet, relaxation ispermissible.

Relaxation of Water Quality-based Limits Under Section303(d)(4)

Section 402(o)(l) prohibits the establishment of less stringent water quality-based effluent limitations “except in compliance with Section 303(d)(4).” Section 303(d)(4) hastwo parts: Paragraph (A), which applies to “nonattainment waters” and Paragraph (B), which applies to “attainment waters.”

l Nonattainment waters: Section 303(d)(4)(A) allows establishment of lessstringent water quality-based effluent limitations in a permit for discharge into a nonattainment water only if (1) the existing permit limitation must have been based on atotal maximum daily load (TMDL) or other WLA established under Section 303, and (2) attainment of water quality standards must be assured.

l Attainment waters: Section 303(d)(4)(8) allows establishment of less stringent water quality-based effluent limitations in a permit for discharge into an attained water as long asthe revised permit limit isconsistent with a State’s antidegradation policy. This isnot restricted to limits based on aTMDL or WLA.

Relaxation of Water Quality-based Limits Under Section 402

Section 402(o)(2) also outlines exceptions to the general prohibition against establishment of less stringent water quality-based permit limits in a permit. Under Section 402(o)(2), the establishment of less stringent limits based on water quality may be allowed where: 1) There have been material and substantial alterations or additions to the permitted facility which justify this relaxation. 2) Good cause exists due to events beyond the permittee’s control (e.g., acts of God) and for which there isno reasonably available remedy. 3) The permittee has installed and properly operated and maintained required treatment facilities but still has been unable to meet the permit limitations (relaxation may only be allowed to the treatment levels actually achieved).

1134) New information (other than revised regulations, guidance, or test methods) justifies relaxation of water quality-based permit limitations. This last exception applies to water quality-based permit limitations only where the revised limitations result in a net reduction in pollutant loadings and are not the result of another discharger’s elimination or substantial reduction of its discharge for reasons unrelated to water quality (e.g., operation termination). Although Paragraph 402(o)(2) lists two additional exceptions, one for technical mistakes and mistakes of law and one for permit modifications or variances, the statute provides that these exceptions do not apply to water quality-based effluent limitations. Asa result, these exceptions do not provide a basis for relaxing water quality-based limitations.

Relaxation of Water Quality-Based Permit Conditions or Standards

The provisions in Section 402(o) discussed previously only address the relaxation of

### effluent limits based on water quality. The relaxation ofother permit conditions or standards based on water quality are governed by EPA’sexisting antibacksliding regulations at 40 CfR 122,44(l)(l). Under these regulations when apermit is renewed or reissued, interim effluent limitations, standards, or conditions must be at least as stringent as the final effluent limitations, standards, or conditions in the previous permit “unlessthe circumstances on which the previous permit was based have materially and substantially changed since the time the permit was issued and would constitute cause for permit modiftcation...“. In other words, unless cause for permit modification is present, relaxed conditions or standards are not permissible. EPA regulations setting forth cause for permit modification can be found at 40 CFR122.62.

Restrictions of Backsliding

Even ifany ofthe backsliding exceptions outlined in the statute or regulations are applicable and met, Section 402(o)(3) acts as a floor and restricts the extent to which water quality-based permit limitations may be relaxed. Paragraph (o)(3) prohibits the relaxation of water quality-based permit limitations in all casesifthere will be a violation of applicable effluent limitation guidelines or water quality standards, including antidegradation requirements. This requirement affirms existing provisions of the CWA that require permit limits, standards, and conditions to ensure comptiante with applicable technology-based limits and water quality standards.

5.8 

## T'OXICITY IlEwlcTltM 

## EVAUJATlWS

Where monitoring indicates unacceptable effluent toxicity, one principal mechanism for bringing a discharger into compliance with awater quality-based whole effluent toxicity requirement isa toxicity reduction evaluation (TRE)[6]. The purpose ofaTREisto investigate the causes and to identify corrective actions for difficult effluent toxicity problems. The permitting authority may require 

### that the permittee conduct aTREin those caseswhere the discharger is unable to explain adequately and immediately correct exceedances of a whole effluent toxicity permit limit or requirement.

A TRE isa site-specific study conducted in a stepwise process to narrow the search for effective control measures for effluent toxicity. TREsare designed to identify the causative agents of effluent toxicity, isolate the sources of the toxicity, evaluate the effectivenessoftoxicity control options, and then confirm the reduction in effluent toxicity. The ultimate objective of a TRE isfor the discharger to achieve the limits or permit requirements for effluent toxicity contained in the permit and thereby attain the water quality standards for receiving waters.

The requirement for apermittee to conduct aTREmay be written into the special conditions section of a permit, which contains whole effluent toxicity limits. In some cases, the permit issuing authority may also use other legally binding mechanisms, including Section 308 letters, Administrative Orders, or Consent Decrees, to require aTRE.



### 5.8.1 RE 8uMance aOeur#rrrls To assistpermittees in conducting TREsand achieving compliance with whole effluent toxicity limits, EPAhas developed a series of three guidance documents [6, 7, 81: 1) Generalized Methodology for Conducting Industrial Toxicity Reduction Evaluations (EPAl600/2-88/070) 2) Toxicity Reduction Evaluation Protocol forMunicipal Wostewater Treatment Plants (EPA/600/2-88/062) 3) Methods forAquatic Toxicity identification Evaluations: Phase 1 Toxicity Characterization Procedures (EPA/600/3- 88/034) Phase 2Toxicity Identification Procedures (EPA/600/ 3-88/035)
Phase 3Toxicity Confirmation Procedures (EPA/600/ 3-881036).

These guidance documents describe the methods and procedures for conducting TREsand Toxicity Identification Evaluations (TIES). They are based on the results of EPA’scontinuing efforts in TREmethods research and case study applications. Separate TRE guidance has been developed for industrial dischargers and municipal wastewater treatment plants to better address the circumstances of each type of facility. Procedures for the characterization, identification, and confirmation of the causative agents of effluent acute toxicity have been developed and are described ina three-phased TIEmethods manual. These TIEmethods are applicable to both industrial and municipal effluents and are an integral part of the protocols for TREsdescribed in the industrial and municipal TREguidance documents. TIE methods using chronic toxicity tests for identifying toxicants will soon be developed and available in adraft guidance document.



### 5.8.2 Ret- &mJ8chflulA%nwmgl7r& To ensure the successful completion of a TRE, the guidance documents recommend a systematic, stepwise approach that

114eliminates the possible causes or sources oftoxicity until asolution or control method is determined. The guidance documents discourage “playing hunches” or implementing extensive control measures solely on the basis of unsubstantiated conclusions (e.g., selecting and implementing a treatment plant upgrade without adequate information). Experience shows that unnecessary delays and expenditures in achieving the objective of the evaluation are avoided by building a sound scientific and engineering basis for selection of a control method. This can best be done by the logical interpretation of the information and data collected in a systematic approach to a TRE. The causes or control methods identified should then go through a confirmation stage. This is especially important in caseswhere the control method selected requires the construction of additional treatment. Aflow chart, generalized from the guidance documents, for this approach to TREsispresented in Figure 5-l 0. The steps in this flow chart are summarized in the following discussion.

Determination of TREObjectives and Development of the TRE Plan Obviously, the success of any study is dependent on a clear understanding ofwhat isto be achieved and how these objectives are to be demonstrated and measured. Typically, TREobjectives are set by the regulatory authority in terms of a toxicity test endpoint (ATE or chronic toxicity endpoint [CTE]) in order to



### I I

TRE Regulatory

Requirements 

# r-l

lnlorrnatlonand Data Acqulsltlon

Facility Operation and Maintenance

IdenUficatlon

Control Method Selectctlon and Implemefltatlon

FoHowup and Conflrmatlon

I I meet a limit or permit condition. TREplans should be submitted by the discharger assoon aspossible. Insome cases,this could be 30 to 60 days following notification that a TRE is required. In other instances, this period could be longer. These plans are important for ensuring that the TRE objectives are well understood and that the TREto be conducted isthorough and represents a reasonable effort to achieve the required reduction in effluent toxicity. An implementation schedule should also be developed describing the timeframe for completion ofthe specific components of the TRE plan by the required TRE completion date. This schedule should be submitted for review in conjunction with the TREplan. EPArecommends that the TREschedule should be set or approved by the regulatory agency. Approval of the schedule and the completion date should not imply approval of the TRE plan itself or the procedures and methods outlined in the plan. Instead, the TRE plan should only be reviewed and any comments provided to the permittee asneeded.

To assistin this review, Box 5-3 provides evaluation criteria for TRE plans. The permitting authority should review the TRE plan and inform the discharger of any apparent shortcomings or potential problems. The TREshould not be delayed pending completion of the review ofthe plan. The specified completion date for the TRE must still be met and the permittee should be expected to begin steps to investigate and alleviate the effluent toxicity as soon as possible following notification that aTREis required. bring the course of the TRE, the regulatory agency should provide oversight, astime permits, to make the TREaseffective aspossible.

Evaluation of Existing Site-specific Information

The next step involves the collection of any information and analytical data relevant to the effluent toxicity. The permittee should begin collecting and evaluating this information assoon as possible following notification that a TRE is required. In some cases, this step may be conducted concurrently with accelerated toxicity testing as part of the development of aTREplan. For an industrial discharger, this part of the evaluation would include information such as plant and process information, influent and effluent physical and chemical monitoring data, effluent toxicity data, and material use. Fora POlW, additional information, such as industrial waste survey applications, local limits compliance reports, and monitoring data, should be collected. This information isused to supplement the data generated inthe later steps of the TRE and may be useful at that stage to point to potential sources or treatment options.

Evaluation of Facility Operations and Maintenance Practices

This part of the evaluation is performed in order to ascertain whether the facility isconsistently well operated and whether the effluent toxicity is Ihe result of periodic treatment plant upsets, bypass, or some other operational deficiency that may be causing or contributing to the effluent toxicity. This part ofthe TREshould be initiated immediately after notification that aTRE is required. Alternatively, the permittee may begin to conduct this step at the same time that any accelerated toxicity testing is required. At both municipal and industrial facilities, this step would involve the evaluation of “housekeeping,” treatment system operation, and chemical use. In some cases, best management practices (BMPs) Figure 5-10. Generalized TRE Flow Chart

115may be identified, which would improve operations and effluent quality. However, the effectiveness of BMPs in reducing effluent toxicity should be carefully confirmed, and it will usually be necessary to test a number of samples and perhaps to conduct Phase 1of the TIEto develop this level of certainty. The results of this evaluation may lead to preliminary strategies for source reduction and pollution prevention, including spill or leak prevention, improvements in material handling and disposal practices, or substitution or re-use of acompound known to be highly toxic. Toxicity Identification Evaluation

TIE procedures are performed in three phases: characterization, identification, and confirmation [7]. In each phase, aquatic organism toxicity tests are used to track toxicity at each step of the procedure. In most cases, these are abbreviated or shortened nature of the causative agents of effluent toxicity or toxicants is determined. This is done by conducting a battery of tests to characterize the physical/chemical characteristics of the toxicity: solubility, volatility, decomposability, complexibility, filterability, and sorbability. This information can then be used to decide which chemical analytical methods will to use in Phase 2 or it can be used to design treatability studies.

The results of Phase 1 also may be used to provide additional confirmation of the effectiveness of any BMP that was implemented in the previous step of the TREto reduce the effluent toxicity. This would require conducting at least one Phase 1 analysis prior to implementation of the BMP (i.e., any source control method implemented as a result of the evaluation of facility operation and maintenance). The results of this analysis would then be compared with Phase 1results from samples taken toxicity tests. In the toxicity characterization phase, the general after BMP implementation.



### Box 5-3. Evaluation Criteria for TRE Plans

. Are the objectives or targets of the TREstated clearly and accurately?

. Are the schedule and milestones for accomplishing the tasks described in the study plan?

. Are the final TREreport, progress reports, and meetings with the regulatory authority included aspart of the schedule?

. Are the approaches or methods to be used described to the extent possible prior to beginning the TRE?

. Has available EPAguidance been used in designing the TREand developing the TREplan (or ifother methods are proposed, are these sufficiently documented)? 1 Does the TREplan specify what results and data are to be included in the interim and final reports?

l Does the TREplan provide for arrangements for any inspections or visits to the facility or laboratory that are determined to be necessary by the regulatory authority?

. Are the toxicity test methods and endpoints to be used described or referenced?

. Does the approach described build on previous results and proceed by narrowing down the possibilities in a logical progression?

. Does the plan provide for all test results to be analyzed and used to focus on the most effective approach for any subsequent source investigations, treatability studies, and control method evaluations?

. Are optimization of existing plant/treatment operations and spill control programs part of the initial steps of the TRE?

l Does the TREplan allow a sufficient amount of time and appropriate level of effort for each of the components of the study plan?

. Does the TIE use broad characterization steps and consider quantitative and qualitative effluent variability?

. Istoxicity tracked with aquatic organism toxicity tests throughout the analyses?

. Isthe choice of toxicity tests for the TRElogical and will correlations be conducted ifthe species used are different from those used for routine biomonitoring?

. Isthe laboratory analytical capability and the expertise of the investigator broad enough to conduct the various components of the evaluation?

116In Phase2ofthe TIE,the results of Phase 1are built upon, and the TIEproceeds to chemical analyses designed to identify the specific chemicals causing effluent toxicity. In Phase 3, the identified toxicants are confirmed using a number of procedures, including correlation of toxicity with chemical concentration, spiking experiments, toxicity mass balance, and additional test species and their symptoms.

The current version of the TIEmethods usesacute toxicity tests to characterize and identify the toxicants. In some cases, these methods may also be used for TREswhere the objective is to reduce chronic toxicity. In order for these methods to be applicable, however, there must be some measurable acute toxicity in the effluent samples that are to be characterized in Phase 1 and analyzed in Phase 2. If this approach is used, the appropriate chronic toxicity test, asspecified in the TREobjectives and permit requirements, should then be used in the Phase 3 confirmation procedures. This will confirm that the toxicant identified using acute tests in Phases 1 and 2, are indeed causing the whole effluent chronic toxicity, which must be reduced.

It ispossible to usethe methods and procedures described in the other components of the overall TREwith either acute or chronic toxicity tests. The fact that the previous version of the EPATIE methods useacute toxicity tests should not be construed to mean that TREscannot be required or conducted for the reduction of chronic toxicity. These methods provide additional tools to assist permittees in the reduction of whole effluent chronic toxicity. Phase 1 procedures that use chronic toxicity tests will soon be available in draft EPAguidance. These TIEmethods are applicable to freshwater discharges to either saltwater or freshwater receiving waters. The use of these methods for saltwater receiving waters may require their adaption for usewith marine test species or, preferably, an initial correlation ofthe recommended freshwater TIEtest species to the marine species used for monitoring.

Source Investigation

Based on the results of the TIE, a decision is made on whether to conduct treatability studies on the final effluent and/or conduct a source investigation. A source investigation is most readily performed when the specific toxicants have been identified and influent samples can be analyzed for the presence of these compounds or when potential source streams can be selected for chemical analysis (based on the results of the initial data acquisition step). However, in some caseswhere the specific causative agents of effluent toxicity have not been identified in the TIE, it may be possible to conduct a source investigation by “treating” influent samples in bench-scale models of the facility treatment plant, measuring the toxicity of the treated sample and then tracking this toxicity to its source.
Source investigations will lead to control methods, such aschemical substitution, process modification, treatment of process or influent streams (pretreatment), and possible elimination of the process. For POTWs, source investigations may lead to the development of local limits or to the requirement that an indirect discharger evaluate and control their effluent so asto reduce its toxicity and prevent passthrough atthe POTW. The implementation of source control methods can effectively reduce effluent toxicity and also can avoid any cross-media transfer of pollutants to air or sludge, which may occur as a result of end of pipe treatment. Types of source control methods that have proven to be effective in reducing effluent toxicity are improvements in facility housekeeping, chemical substitution, process optimization, reclamation/reuse, and pretreatment. Toxicity Treatability Evaluation Toxicity treatability evaluations are conducted to identify possible treatment methods that can effectively reduce effluent toxicity and may involve modifications or additions to the existing system. Treatability studies generally usethe same type of information on the nature of the chemicals to be removed as is generated by Phase 1 of the TIE. These treatability tests should be conducted on a bench-scale initially and then a pilot scale prior to construction of additional treatment or substantial modification of the existing plant. The use of these bench- and pilot-scale tests, coupled with aquatic organism toxicity tests, should be used to confirm the effectiveness of the treatment option. Confirmation of the results of treatability studies isequally important as it isfor the TIE. Skipping this confirmation step is an invitation for unwarranted expense. Toxicity Control Method Selection and Implementation

After the investigative steps of the TREare completed, it is not unusual for a number of possible control options to have been identified. At this point, asite specific selection must be made by the discharger based on the technical and economic feasibility of the various alternatives. Following this selection, the toxicity control method is implemented or a compliance plan issubmitted if construction of additional treatment requires a substantial amount of time.
Followup and Confirmation

After the control method isimplemented and the final TREreport issubmitted, the permitting agency should direct the permittee to conduct followup monitoring to confirm that the reduction in effluent toxicity isattained and maintained. Normally, this monitoring should follow an accelerated schedule, weekly or biweekly toxicity tests, for a period of 2 to 3 months to confirm the effectiveness of the controls implemented and the continued attainment of the TREobjective. Thisfollowup monitoring should usethe same species aswere specified for routine toxicity testing in the permit. The test endpoints of these toxicity tests should be the same as those which were calculated by the water qualitybased permit limit derivation procedure used when the permit was issued. Once the discharger hasdemonstrated the successful completion of the TRE,the permitting agency should direct the discharger to return to the routine permit monitoring schedule.



### 5.8.3 l%wmstmcas WmatttingaTRE It isthe responsibility of the permitting authority to determine if the permit limits and/or the State water quality criteria have been threatened or violated and to notify the permittee if a TRE is required. It isappropriate for the permitting authority to require additional toxicity testing following the initial exceedance or violation. This additional testing may precede notification that aTRE will be required or it may be considered asthe initial part of the

117TREand be conducted simultaneously with TRE plan development and the evaluation of other existing site-specific information.

It is important to recognize that the purpose of this additional toxicity testing isto determine the continued presence or absence of effluent toxicity and the magnitude of that toxicity. This information can then be used to determine the continued compliance or noncompliance with the limit or permit conditions for effluent toxicity. These tests do not serve to verify or confirm the initial test results from an earlier sample. Instead, the permit authority shall usethe results ofthese teststo determine ifaTREor some other action isthe appropriate response to the initial occurrence of toxicity.

Ifthe permit hasa limit for whole effluent toxicity, then generally, the permit should not include any specific conditions for accelerated toxicity testing or for triggering aTREor some other action (e.g., exceedances intwo consecutive tests or exceedances in any three out of five tests). CWA Section 309 requires that any single violation of a permit limit may be subject to enforcement. The EPA Compliance Monitoring and Enforcement Strategy for Toxics Control (January 19, 1989, Appendix 8-4) states that, “Each exceedance of adirectly enforceable whole effluent toxicity limit isof concern to the regulatory agency and therefore qualifies as meeting the VRAC [violation review action criterion] requiring professional review.” Accelerated monitoring should only be used to assistin this professional review to determine what, ifany, enforcement response is necessary, including the need for the permittee to conduct aTRE. Itwill be necessary for the Region or State regulatory authority to determine this on a case-by-case basis. This must be done in a manner consistent with the priorities established in their respective toxics control strategies and permitting procedures.

In situations where it is determined that accelerated testing is appropriate, a maximum ofweekly testsfor aminimum period of 2 months is recommended. This would result in eight tests, plus the routine monitoring toxicity test that initially indicated the exceedence orviolation, for atotal of nine tests in the series. Asa practical approach for determining if a TRE is an appropriate response, EPA recommends if toxicity is repeatedly or periodically present at levels above the effluent limits more than 20 percent of the time, a TRE should be required. With toxicity present at this rate, the TREprotocols will be useful.

In most cases, any one additional exceedance (beyond the initial routine monitoring toxicity test result) in the accelerated toxicity tests could result in notification of the permittee that a TRE is required. Exceptions to this guideline might include caseswhere the permittee isable to adequately demonstrate that the cause of the exceedances is known and corrective actions have been immediately implemented or cases where additional test quality assurance/quality control (QA/QC) isnecessary or desirable. The submittal of QC fact sheets for self-biomonitoring (e.g., Appendix 6-2) should always be recommended to avoid QA/QC problems.

If the test results indicate that toxicity is not consistently or repeatedly present in the test series, previous discharge monitoring reports (DMRs) should be examined to ascertain ifa recurrent problem exists. If the problem is recurrent, a TRE should be required, and the TREplan should explain how the design of the evaluation will address this periodic or recurrent effluent toxicity problem. In these cases, more elaborate sampling design and influent or process stream monitoring may be needed. It should be expected that TREsconducted under these circumstances will probably require a more flexible schedule and perhaps additional time before the required completion date.

Ifthe accelerated testing and previous DMRs show the continued absence of effluent toxicity, 

### then the initial exceedance would be considered an episodic event and aTREshould not be required. A TRE is not an appropriate response to a single, episodic effluent toxicity event (e.g., a spill or a plant upset). By conducting accelerated testing following a violation or exceedance of a permit condition, unnecessary TREscan be avoided. Similarly, conducting accelerated testing aspart of the initial steps of aTREwill allow for the TREto be ended in itsvery early stages ifthe toxicity isimmediately controlled or determined to be episodic or nonrecurrent. Byfollowing the TREguidance and incorporating accelerated testing into the TRE,unnecessary analyses and expense can be avoided.

It also is important to note that for the practical purposes of conducting aTRE(as opposed to the purpose of determining ifa TRE should be required or not), the magnitude of the effluent toxicity needed to conduct aTREmay be lessthan the magnitude or level set as the permit limit or permit monitoring condition. This is because if the limit or monitoring condition is water quality-based then some amount of dilution will usually be incorporated in determining the unacceptable level of effluent toxicity. In some cases, it may be possible for the TRE procedures to be carried out even if the toxicity does not actually exceed this permitted level. This will be the case as long as the effluent toxicity is periodically or consistently present in measurable amounts in samples of loo-percent effluent.

It also is reasonable for a discharger to initiate aTREprior to the establishment ofapermit limit for toxicity ifunacceptable levels of toxicity are found in the effluent through routine monitoring or through inspection and compliance sampling by the regulatory authority. Under 

### these circumstances the regulatory authority will need to identify what constitutes unacceptable levels of toxicity since this will not be defined by a permit limit (see Chapter 3 on determining the reasonable potential for excursions of water quality standards). It also isnot unreasonable for 

### the discharger to voluntarily initiate aTREunder 

### thesecircumstances.

There are a number of mechanisms that can be used to require a TRE. In most cases,the TREshould be required by a Section 308 letter or by an enforcement action, such asa Section 309 Administrative Order or aConsent Decree. The permittee should receive notification from the permit authority of what response is required. This enables the permit authority to assesswhether aTRE isthe appropriate action to pursue. Ifeffluent toxicity reappears following the successful completion of a TRE, then the permit authority should be able to review this type of situation to determine ifan additional TREisappropriate or ifsome other action is required. In general, when the permit is issued with whole effluent toxicity limits in Part 1 of the permit, TRE requirements should be used where necessary to bring the permittee into compliance with those limits. Box 5-4 provides example lan118guage for effluent toxicity limits, developed as part of the Whole Effluent Toxicity BasicPermitting Principles and Enforcement Strategy (Appendix B-4).

Box 5-5 presents sample language for use in requiring TREsby a Section 308 letter or a Section 309 Order. This sample language, especially the reporting dates, should be tailored to fit the specific permittee. The completion date should be specified on acase-bycase basis. Factors to consider in setting this completion date include the type of facility, the variability of the effluent, and the previous compliance history. In order to conduct aTRE, reasonable timeframes are 6 to 18 months for an industrial discharger and 12 to 24 months for amunicipal wastewater treatment plant. For POlWs, it may take longer to conduct aTREdue to lengthy government contracting procedures, large sewer collection systems, and less influent constituent control. It should be recognized that extensions to these initial timeframes may be granted if the progress reports demonstrate 

### that this iswarranted. Insituations where reductions in chemical concentrations to meet chemical-specific limits are needed as well as reductions in effluent toxicity, the timeframes may be adjusted to enable those efforts to proceed simultaneously.



### Box 54. Model Permit Language for Effluent Toxicity Limits

Part 1.A. Final Effluent Limits and Monitoring Requirements
During the period beginning on the effective date of this permit and lasting until the expiration date, the permittee isauthorized to discharge in accordance with the following limits and monitoring requirements from the following outfall(s): 001.

Effluent Characteristic Discharge Limit Concentration Reporting Daily Monthly Code/Units Parameter Maximum Average Monitoring Requirement

Measurement Sample

Frequency Type

-TUc Toxicity 10.0 5.0 x/month composite

The permittee shall usethe toxicity testing and data assessment procedures described in Part 3.8 of this permit.



### Box 5-5. Example Language for Requiring Toxicity Reduction Evaluations

The discharger shall demonstrate that effluent toxicity-based permit limits described in Part 1.A. of the permit are being attained and maintained through the application of all reasonable treatment and/or source control measures. Upon identifying noncompliance with those limits the discharger shall initiate corrective actions according to the following schedule: Task Deadline
1. Take all reasonable measures necessary to Within 24 hours reduce toxicity immediately.
2. Submit a plan and schedule to attain continued Within 30 days compliance with the effluent toxicity-based permit limits in Part I.A.,where source of toxicity is known, if immediate compliance is not attained.
3. Submit aTREstudy plan detailing the toxicity Within 45 days eduction procedures to be employed where source is unknown and toxicity cannot be immediately controlled through operational changes. EPA’sToxicity Reduction Procedures, Phases 1, 2, and 3 (EPA-600/3-8Bi034, 035, and 036) and TRE protocol for POTWs (EPA-600/2-88i062) shall be the basis for this plan and schedule.

119

### Box 5-5. Example Language for Requiring Toxicity Reduction Evaluations (continued)

4. Initiate TRE plan. Within 45 days
5. Comply with approved TREschedule. Immediately upon approval 6. Submit results of the TRE, including summary of Per approved schedule findings, corrective actions required, and data generated.
7. Implement TREcontrols asdescribed in the final report. On due date of final report per approved schedule 8. Complete TRE implementation to meet permit limits Per approved schedule, but and conditions. in no case later than XX months from initial noncompliance.

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## CHAPTER 5 REFERENCE5

1. Marr, J.K.,and R.P.Canale. 1988. Load Allocation for Toxics 5. U.S. EPA. 1987. Development Document for Effluent CuideUsing Monte Carlo Techniques. /ourno/ WPCF60(5):659- lines and Standards for the Organic Chemicals, Plastics and 66. Synthetic fibers Point SourceCateqow, volumes 1and 2; EPA
2. Freedman, P.L., 1.F.Penderqast, C. Wilber, and S.C. Chanq. 440/l -87/009. 

### - ,

1988. Seasonal Changes and Effluent Limits. )ouma/ WP<f 6. U.S. EPA. 1988. Toxicity Reductions Evaluation Protocol for 60(3):317-23. Municipal Wastewater Treatment Plants. EPA/600/2-88/
3. Parkerton, T.F., S.M. Stewart, K.L. Dickson, J.H. Rodgers, and 062. F.Y.Saleh. 1989. Derivation of Site-Specific Water Quality 7. U.S. EPA. 1988. Methods for Aquatic Toxicity ldentificotion Criteria for Zinc: Implications for Wasteload Allocation. Evaluations: Phase 1,Toxicity Characterization Procedures Researchjournal WPCF61(11 ,12):1636-44. (EPA/600/3-88/034); Phase 2, Toxicity identification Proce4. Shell Chemical Company NPDES Permit Nos. LAOO05762, LAOO50962, TXOO048663, Appeal No. 85-l 4, 85-15, 85 dures (EPA/600/3-88/035); and Phase 3, Toxicity Confirmation Procedures (EPA/600/3-88i0360.
16 before the Administrator,’ U.S. EPA. U.S. .EPAJudicial 8. U.S. EPA. 1988. Generalized Methodology for Conducting InOfficer decision, October 20, 1987. dustrio/ Toxicity Reduction Evaluations. EPAJ600/2-88/070.



## ADDlTlONAl REFERENCES

Aitchinson, J.,and J.A.C Brown. 1963. TheLognormal Distributions. London: Cambridge University Press. Cilliom, R.H., and D.R. Helse. 1986. Estimation of Distributional Parameters for Censored Trace Level Water Quality Data 1and 2. Water ResourcesResearch22:135-55. Kahn, H.D., and M.B. Rubin. 1989. Use of Statistical Methods in Industrial Water Pollution Control Regulations in the United States. Environmental Monitoring and Assessment 12:129-48. Shumway, R.H., A.S. Azari, and P.Johnson. 1989. Estimating Mean Concentrations Under Transformation for Environmental Data with Detection Limits. Technometrics 31(3):347-56.

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# 6. COMPLIANCE MONITORING AND ENFORCEMENT

6.1 INTRODUCTION

Once a water quality-based permit containing limitations and conditions to control effluent quality is issued, the permittee is responsible for attaining, monitoring, and maintaining compliance with the requirements of that National Pollutant Discharge Elimination System (NPDES) permit. Failure to comply with any requirements stated in the permit isaviolation ofthe Clean Water Act (CWA).

The Environmental Protection Agency (EPA)and authorized State agencies are responsible for tracking compliance with and enforcing NPDES permit requirements in the enforcement of the CWA. Section 308 of the CWA and equivalent State statutes enable the regulatory agency to verify compliance with permit conditions (including water quality-based toxics limitations and compliance schedules) by authorizing the agency to impose on permittees requirements for sampling and analysis, record-keeping, and reporting. Section 308 also authorizes access by EPA or State agencies to facilities and records for verifying compliance with permit conditions. All records associated with monitoring must be maintained by the facility and available for a 3-year inspection period in conformance with 40 CFRPart 122.41.

The CWA establishes the authority to enforce water quality-based permit conditions. The ability to enforce water quality-based permit conditions, however, relies on well-written, clearly stated permits. The enforcement official must be familiar with the process by which permit requirements were derived, including the procedures used to determine the wasteload allocation based on applicable water quality standards and the procedures used to derive limitations from the wasteload allocation.



## 6.2 PERMIT REQUIREMENTS

The conditions that are to be included 

### in NPDES permits are described in 40 CFRPart 122 Subpart C. In general, permits include effluent limitations, schedules of compliance, and accompanying reporting requirements. Permits should prescribe the self-monitoring procedures, frequency of analysis, sampling location and procedures, acceptable or required analytical techniques, and frequency of reporting. Permits often require that analytical methods referenced in 40 CFR136 be used for analysis, but may specify methodology not included in Part 136 for pollutants with no approved methods or where the approved method isinappropriate for aparticular permit limitation. Permits should define any effluent limitations and explain specific procedures for calculating averages of data if different from arithmetic averaging. Permits should identify what information must be retained by the permittee, and what data must be submitted to EPAorthe State. Results from self-monitoring required by the permit are reported on discharge monitoring reports (DMRs) that generally are submitted monthly. Sampling and analysis 

### that isdone more frequently than required by the permit must be included in the DMR.



## 6.3COMPLIANCE MONITORING

Since most of the routine information gathered in compliance monitoring results from permittee self-monitoring, quality assurance (QA) isasimportant ascompliance with limits. It isessential that permittees develop and adhere to a QA plan consistent with the required monitoring and analyses. The permittee isresponsible for maintaining data to demonstrate compliance with QA procedures established in the test methodology or as specified in the permit.

The regulatory agency generally has three ways of determining compliance with an NPDES permit and assuring adequate QA: self-monitoring reports, DMR/QA results, and inspections. Each of these methods isdiscussed below.



### 6.3.1Self-monitoring Reports Self-monitoring reports provide much of the compliance data used by the regulatory authority in the review of permittee compliance. These reports include DMRs and reports of progress on compliance schedules. DMRs contain information on the sampling method, frequency and location, and analytical results of permittee self-monitoring. These data and data from progress reports on major schedule milestones must be entered into the Permit Compliance System (PCS), a computerized data base, by the State or EPA[1]. When the required data are entered into the system, PCSwill automatically “flag” violations of permit limitations, compliance schedules, and reporting requirements.

In order to detect any problems with the quality of the sample analysis, it is often desirable to obtain QA information with the self-monitoring data. For this reason, several States and Regions have developed additional QA forms to accompany permittee self-monitoring reports, This additional information may be required through the permit or through a Section 308 order. The QA data are compared to a reference QA data sheet that can be completed by the regulatory authority to indicate acceptable ranges ofvalues for the required protocol. Appendix B-5 provides an example of a reference QA data sheet for a whole effluent toxicity test. Once completed, this QA data sheet can be included inthe compliance filefor quick reference by compliance personnel.

It is important to note that poor QA is a violation if the permit explicitly specifies adequate QA or references an acceptable protocol with corresponding QA procedures. It also is important to note that the signatory’s certification of effluent data certifies

123

### compliance withthespecifiedprotocols.Anyproblems withQA shouldbereportedatthetimeofDMR submission andthetesting repeated.

6.3.2 Discharge Monitoring Report/Quality Assurance (DMR/QA) TheDMR/QAprogramevaluates apermittee’sabilitytoanalyze andreportaccuratedata. Thisprogramisintendedtoimprove overalllaboratoryanalyticalperformance forself-monitoring data. Authorityfor requiringparticipationis grantedin CWASection 308.IntheDMR/QA program,permittees arerequired toanalyze “blind” samples withconstituents andconcentrations thatcanbe foundintheirindustrialormunicipalwastewaters.Thepermittees’resultsarecomparedtotheknowncontentofthesample, andanevaluationofthereporteddataissenttothepermittees. Permittees areexpectedtousethesame personnel andmethods employedfor reporting NPDES datato analyzethe samples. Permittees arerequiredtofollowthe instructionsfor reporting results andincludeasignedcertificationstatementinaccordance with40CFR 122.22. Regulatory agencies conductfollowupinvestigations to address poororincompleteDMR/QAresults, failuretoparticipate,orlate submittalofDMR/QAresults.DMR/QAperformanceresults are compiledannually.
In the past,only chemical-specific analyses weretestedin the DMR/QAprogram.TheEnvironmental MonitoringandSupport Laboratory (EMSL) inCincinnatihas developed areference toxicant DMR/QAsamplefor permitteeswith whole effluent toxicity monitoringrequirements.Nationalimplementationisoccurring in 1991.

6.3.3 Inspections Inspections areconductedbytheregulatoryauthorityoritscontractorsto address specificviolationsor problemsandtoverify permitteecompliance withpermitconditionsandQAprocedures. Inspections mayincludereviewingrecords, inspectingtreatment facilities, assessing progress withcompliance schedules, evaluating laboratoryfacilitiesandperformance, andcollectingsamples for analysis or“splitting” samples takenbythepermitteeforconcurrentanalyses.EPA hasdefinedseveral typesofinspections based onthetasks thatareincludedintheNPDES Compliance inspection Manual[2]. Because regulatory authorities areexpected toinspect all majorpermitteesannuallyregardless of compliancestatus, nonsamplinginspections(which aregenerallylessresource-intensive)areencouraged forroutineevaluationofpermitteeperformance.However, samplinginspections arestillencouraged to address permittingandenforcementpriorities. Forthat reason, the regulatoryagencymust havethe full capabilityto assess effluent compliance throughinhouse resources orcontract support. Inspections thatfocusontoxicscontrolcanprovideusefulinformationforwaterquality assessment and permit reissuance in additiontocompliancedata. Procedures forinspectingfacilities withtoxicitytestingrequirements andmeasuring effluenttoxicity aredetailedintheNPDES Compliance inspection Manual,Chapter 7[2]. 6.4 VIOLATIONREVIEW
Review ofpermitteeself-monitoringdatatodetermineappropriateenforcementresponse generallyinvolvesatwo-tieredreview. Thefirsttierisapreliminaryreviewfortimely,completedatathat indicates compliance with permitrequirements.Minorviolations ofrequirements areoftenhandledthroughinformalphonecalls orwarninglettersthatdonot requireextensiverevieworoversight.As violationsincrease inmagnitude,duration,orfrequency, theygenerallyareassigned topersonnel whoareresponsible for thesecond-tierreview(determiningwhatenforcementaction,if any,isappropriate).Theguidelines forthisprocess arepresented intheEnforcement ManagementSystem (EMS) [3],but thebasic conceptsof responsiblecompliancetrackingofwaterqualitybasedrequirements arediscussed below. Section6.5discusses theenforcement decisionprocess. Whentheinitialreviewofeffluentmonitoringdataindicates that unacceptable analyticalmethodswereusedbyapermitteeorits contractlaboratory,theresults shouldbeassigned forreviewby personnel qualifiedtodeterminethesignificance oftheresults.If themonitoringisinsufficient todeterminecompliance witheffluent limitations,awarning letteror Section308letterrequiring thatthetestsberepeatedusingacceptable procedures wouldbe anappropriateresponse. Trackingapermitor Section308letterthat contains“monitor only” requirementsrequiresbothacompliancereview(e.g.,to determineif resultsof acceptablequality weresubmittedon time), andan action review(e.g.,to determineif the permit shouldbemodifiedor re-issued to includealimitation). This secondreviewshouldbeassigned topersonnel whoarequalified tomake thisregulatorydecision.
Inadditiontotheguidelines forreviewingmonitoringdatainthe absence ofaspecific effluentlimitation,EPA also hasrecommended acriterionfordeterminingwhicheffluentviolationsmustbeassignedforreviewbyaprofessional whowilldetermineifaformal enforcement actionisneeded, orifaphonecall,warningletter,or Section308letterismoreappropriate.These criteriaareknown astheViolationReview ActionCriteriaandarelistedintheEMS.
Inthecaseofawholeeffluenttoxicity limitation,anyviolation mustbereviewedbyaqualifiedprofessional responsible forthe enforcement decision.EPA makes thisrecommendation toensure thatadequate attentionisgiventoQAandtoensure thatadditional testingisrequiredifpermittedtestingfrequencyisless thanonce permonth.
Inthecase ofaviolationofachemical-specific permitlimitation, EPA recommends that monthlyaveragelimitationviolationsbe reviewedbya professional for potentialenforcementresponse whenever twoormoreviolationsoccurina 6-month period. Seven-day average anddailymaximumviolationsshouldlikewise be reviewedifa minimumoftwo orfour, respectively, occur duringthecourseof1month. Althoughthereisnodelineation betweentechnology-based versus waterquality-based limitations intheseViolationReview ActionCriteria,Regions andStates may wishtoadoptacriteriaof “anyviolation”forallwaterquality124

### ..-_

based, chemical-specific limitations as these criteria are solely to determine the level of review and do not prescribe enforcement action.



## 6.5 EWFORCEMENT

Effective enforcement of toxic controls depends upon clearly expressed requirements in NPDES permits. These controls are generally in the form of numeric limits on specific toxic chemicals or whole effluent toxicity and schedules to initiate construction or other compliance measures. Exceeding a permit limitation is a violation subject to enforcement. Some members ofthe regulated community have expressed concerns that single violations of stringent water quality-based limitations will result in unreasonable enforcement actions. EPA’s guidance outlines asystematic review ofallviolations to determine the appropriate level ofresponse. This guidance generally suggests an informal response for minor or infrequent violations, escalating to formal enforcement and perhaps penalties for more frequent and environmentally harmful violations.

In evaluating appropriate response to violations, EPA’s“Enforcement Response Guide” of the EMS should be used for guidelines on the minimum acceptable response [3].

Further guidance on addressing violations ofwhole effluent toxicity limitations in particular ispresented inthe Compliance Monitoring and Enforcement Strategy for Toxics Control [4] (seeAppendix t3- 4). This strategy expects that all available avenues to compliance will be explored by the permittee, that the treatment facility is designed, constructed, maintained, and operated to achieve all water quality-based, chemical-specific or best available technology/ secondary treatment limitations, that chemical or process substitutions have been attempted and pretreatment explored, and that, in the case of publicly owned treatment works (POTWs), pretreatment program requirements and local limits have been established and enforced. The strategy further expects that the permittee will pursue a Toxicity Reduction Evaluation (TRE) as discussed in Chapter 5 in compliance with enforcement requirements or under its own initiative. Ifall of these expectations have been met and the facility isunsuccessful in identifying the cause, source, or treatability oftoxicity despite making good-faith efforts to do so, the strategy allows for relief from civil penalties. The underlying responsibility to achieve compliance with the permit limitation remains in effect.

Some members of the regulated community have requested EPA and several State agencies to define more clearly enforcement discretion with respect to violations of whole effluent toxicity limitations. To define enforcement discretion would in effect make it no longer discretionary. Furthermore, the purpose of such guidance would be questionable as individual enforcement responses by EPAand the States are open to review by the public and the courts. In lieu of such additional guidance on enforcement discretion, it is recommended that Regions and States adhere to the principles presented inthe EMS,the strategy, and in this document. EPAalso has developed a policy [S] on the assessment of appropriate civil penalties in both administrative and civil judicial actions in response to any CWA violation. This policy bases the penalty amount on the seriousness of the violation, the economic benefit enjoyed as a result of delayed compliance, any history of suchviolations, any good-faith efforts to comply, and the violator’s ability to pay. In no instance can this calculated penalty exceed the statutory maximum penalties defined in CWA Section 309.

If any violation occurs, the permittee has the responsibility of informing the regulatory agency. If the violation potentially endangers health or the environment, 

### the violation must be verbally reported to the regulated agency within 24 hours and the permittee must submit a noncompliance report within 5 days of violation detection. Ifthere is no danger to health or the environment, the written report must be submitted at the time monitoring reports are submitted. These reports must include a description ofthe violation, itscause, the period ofnoncompliance, and ifthe noncompliance has not been corrected, the anticipated time when compliance will be achieved.

As with other NPDES permit limitation violations, violation of a water quality-based toxics limit should prompt immediate action on the part of the permittee. Permittee response should include evaluation of the cause of the violation, correction of operational deficiencies or improvement of treatment efficiency, and any other initial steps necessary to resolve the violation and mitigate the environmental effects. These immediate investigatory and corrective steps also should provide information that may be used in developing acompliance schedule ifthe violation isnot resolved quickly.

When awater quality-based toxicity limit isviolated, the regulatory agency may require additional monitoring to determine the frequency and duration ofthe violation. Ifthe permit limit isnot met quickly through improved housekeeping, operation, or raw waste control (e.g., POW enforcement of pretreatment requirements, or chemical substitution by industries), requiring aTREasdiscussed in Chapter 5 may be appropriate. Where toxicity-based limitations are in effect, the enforcement response must require expeditious compliance with the limit.

Available enforcement mechanisms include Section 308 orders, Section 309 Administrative Orders, Administrative Penalty Orders with Administrative Orders, orjudicial action. Enforcement action must be tailored to the specific violation and type of remedial action required. Enforcement actions must be worded carefully sothat they clearly are understood, easilytracked, and expeditiously enforced. Violating limitations of pollutants at concentrations that pose a threat to human health should receive immediate enforcement attention to prompt rapid resolution of the noncompliance. The regulatory agency should consider the pollutant concentration, exposure route, and whether or not the pollutant exhibits a threshold response in determining if aschedule may be allowed. Immediate injunctive relief (such asatemporary restraining order or preliminary injunction) should be sought when necessary to protect public water supplies and fish and sheltfish areas from imminent or substantial impairment.

125

## 6.6 REPORTlWGOFVlCHAllOS

The regulatory authority isresponsible for reporting to the public on permittees in violation. Reporting requirements for the Quarterly Noncompliance Report (QNCR) of major permittees in violation of their NPDES permits are established in 40 CFR123.45. Reporting of violations of water quality-based monitoring, limitations, schedules, and reporting requirements by major facilities must be consistent with 40 CfR 123.45. Violations of permit or enforcement order conditions by major permittees must be reported asfollows [6]:

l Effluent violations (chemical-specific and whole effluent toxicity) must be reported on the QNCR ifthe violation hasthe

. potential to have caused a water quality problem (40 Cf!7 123.45(a)(z)(iii)(A)(l)).

l Chemical-specific toxic permit limit violations must be reported on the QNCR if two or more monthly average measurements in a 6-month period exceed the limit by a l factor of 1.2 for a Group I parameter or 1.4 for a Group II parameter asdefined in the Regulation, or iffour or more monthly average measurements in a 6-month period exceed the limit by any amount (40 CFR123.45(a)(2)(ii)(C)). Any violation during the quarter of an interim monthly average chemical-specific toxic limit established in an administrative order or court order/consent decree must be reported 

### onthe QNCR (40 CFR123.45(a)(2)(ii)(A)). (Note: Whole effluent toxicity is not characterized asa Group I

### or Group II parameter, and as such, must be evaluated on a professional judgement basis under 40 CFR 123.4S(a)(2)(iii)(A)(l).) Compliance schedule milestones that are not met within 90 days of the scheduled date must be reported on the QNCR (40 CFR123.45(a)(Z)(ii)(B)).

Failure to submit a report within 30 days of the due date must be reported on the QNCR (40 CFR123.45(a)(Z)(ii)(D)).

126

## CHAPTER 6 REFERENCE6

1. Jensen, L.]. Permit Compliance System (PCS)PolicyStatement.
2. NPDESCompliance Inspection Manual, May 1988. 3. Enforcement Management System for the National Pollutant Discharge Elimination System, September 1986.
4. Hanmer, R.W. 1989. Who/e Effluent Toxicity BasicPermitting Principles and Enforcement Strategy. 5. Jensen, L.J. 1986. C/eon Water Act Penalty Policy for Civil Settlement Negotiations. 6. Hanmer, R.W. 1986. Guidance for Prepurotion of Quarterly and Semi-Annual Noncompliance Reports.

127

# 7. CASE EXAMPLES

7.1INTRODUCTION

This chapter presents examples of the development of water quality-based discharge limits to illustrate the integration of the guidance ofthe previous chapters. There are three examples: an industrial discharge with ample dilution, a publicly owned treatment works (POTW) with moderate dilution, and the combination of an industrial facility and a POTW discharge to the same reach.



## 7.2CASE:1 INDUSTRIAL DISCHARGE

The first example is the Jaybird Corporation, a metal finishing firm. The NPDES permit for the facility isabout to expire, and the corporation has submitted an application for a new permit. The example shows the steps that a permitting authority would take to determine if a water quality-based effluent limit is necessary and then to establish such a limit. The example also illustrates when best available technology (BAT) limits are applied instead of water quality-based limits, the use of human health criteria, and the variations in the limits derived by different wasteload allocation methods. •

•

•



### 7.2.1 General SiteDescription andInformation The Jaybird Corporation facility discharges into the Locapunct River. The river isapproximately 60 miles long and its banks are occupied by small towns separated by woodland and farmland. The river isclassified by the State inthe water quality standards as having designated uses of a fish habitat, primary contact recreation, and adrinking water supply. Forthese uses,the State has adopted the federal water quality criteria into the water quality standards to protect aquatic life and human health. The State standards also includes a narrative criterion of “no toxics in toxic amounts” for other toxic materials.

Water quality monitoring indicates some infrequent excursions above water quality criterion for copper and nickel. These pollutants have been found in measurable quantities in the effluents of several facilities.

The Jaybird Corporation isa metal finishing facility that specializes in copper plating of lead shells for a nearby military installation, Asa metal finisher, the Jaybird Corporation isrelatively small with adischarge of 0.034 cfs(0.022 mgd). The effluent at the Jaybird Corporation is treated by precipitation and settles before discharge through a multiport diffuser. The corporation issubject to BAT and best practicable technology (BPT) effluent limits for the metal finishing industry.



### 7.2.2 Effluent Characterization forSpecific Chemicals The permitting authority has adopted a procedure in which pollutants concentrations in each facility are evaluated for the potential to cause, have the reasonable potential to cause, or contribute to an excursion ofthe water quality standards. The authority used the effluent characterization process for specific chemicals described in Chapter 3in this evaluation. Ingeneral, the procedures are designed to determine which pollutants are of concern and which require effluent limits. Step 1: Identify Pollutants of Concern

Data were obtained from a number of sources to identify and quantify the pollutants of concern in the Jaybird Corporation effluent:

Effluent chemical concentrations were taken from the Permit Application Form 2C, Discharge Monitoring Reports (DMRs), EPA’s Permit Compliance System (PCS), and permit files.

EPA’sSTORETdata base was used to obtain U.S. Geological Survey flow data and ambient monitoring data for the river.

BAT limits for the metal finishing industry were obtained from 40 CFR433 Subpart A.

The permitting authority noticed in review of these data that the information in Form 2C replicated the information in the DMRs, and therefore decided to usethe DMR data asthe primary basis for characterizing the effluent. These data for toxicants DMRs are shown in Table 7-1. Forthose parameters currently not covered by the permit, Form 2C data indicated that pollutant concentrations were below detection limits. The permitting authority requested information from the facility showing the detection levels used; these levels were consistent with the detection levels listed in the National Pollutant Discharge Elimination System (NPDES) regulations at 40 CFR136.

The effluent from the Jaybird Corporation is regulated by the Metal Finishing Point Source Category effluent guidelines at 40 CFR433 Subpart A. These guidelines regulate the following toxic pollutants: cadmium, chromium, copper, cyanide, lead, nickel, silver, zinc, and total toxic organics.
Although these parameters were regulated at the Jaybird Corporation, the only toxic pollutants evident in the discharge were lead, copper, and nickel. The facility’s treatment system reduced concentrations of other pollutants to below detection.

Step 2: Determine the RAC, CMC, and CCC for Pollutants of Concern

The State has adopted numeric water quality criteria for acute toxicity (criterion maximum concentration [CMC]), chronic toxicity (criterion continuous concentration [CCC)), and protection of human health (reference ambient concentration [RAC]). The water quality standards present the CMC and CCC criteria as equations based on ambient hardness concentrations. The standards require that the 85th percentile lowest hardness be used. This value is 100 mg/l asCaC03 for the Locapunct River. 129

### Table 7-1. Effluent Datafor the Jaybird Corporation

n
1 2 3 4 5 6 7 8 9 10 11 12 Copper Lead Nickel Toxicity μg/l μg/l μg/l TUC 1,317 187 223 5 1,092 230 261 10 1,073 258 464 5 1,059 423 341 20 1,072 227 369 1,677 275 1,058 2,664 364 199 1,058 170 259 3,439 259 437 6,596 264 773 1,211 267 300 1,082 175 356
Mean 1,945 258 420 10 SD 1,650 74 252 7.1 CV 0.8 0.3 0.6 0.7 Max 6,596 423 1,058 20 Min 1,058 170 199 5 N 12 12 12 4
Source: DMR data forchemicals; 308 request forwhole effluent oxicity. Notes:

Metals reported astotalrecoverable metals; toxicityreported inchronic toxic units (100/NOEC). The permittee didnotuse ageometric dilutionseries forthetoxicity tests. The results are thehighest oxicunits forany ofthetest organisms used.

The aquatic toxicity criteria for metals in the standards areexpressedasthe acid soluble form of the metal. The State has adopted aratio to expressthe acidsolubleform of metalsasthe total recoverable form for the purposes of developing NPDES permit limits. Thisratio isbasedon historical datathat the State hascollectedfor riversinthe basinwherethe Locapunct lies. The valuesofthe ratioare0.35for lead,0.70forcopper, and0.85for nickel. The standards consider the criteria for human health protection to beinthe total recoverableform ofthe metal.
Basedon the hardnessand acid soluble-to-total recoverable ratios,the applicable statewater quality criteria arethefollowing:

Pollutant Lead Copper Nickel CCC CMC RAC μg/l μg/l μg/l

9.1 235 50 17.1 25.7 NA 188 1,647 13.4

Step3: Determine Dilution for Aquatic life and Human Health Impacts
The Statewater quality standards require that compliance with waterquality criteria beachievedattheedgeofthe mixing zone. Thestandardsspecifythe minimum dilution atwhich the criteria apply. Thesearethe 7Q10flow for the CCC,the 1Q10flow for theCMC, andthe harmonic meanflow for human health criteria (RAC). The U.S.Geological Surveyoperatesagaging station on the river; the flow statisticswere calculated using the datafrom thisstation:

• Harmonic meanflow =38.0cfs

• 7Q10flow =13.0cfs

• 1Q10flow= 10.1cfs.
Thefacility provided astudy of the outfall that showed that the multiport diffuser quickly achieved complete mixing acrossthe width ofthe river. Dilution atthe edgeofthe mixing zonecould therefore becharacterized bythe complete mixing equation:
C=(CemQe +CsQs/(Qe +Qs)
where

C =the receivingwater concentration
Cem= the maximum effluent concentration
Qe =theeffluent flow
Cs =the receivingwater background concentration
Qs = the appropriate receiving waterflow.

Step4: Determine Reasonable Potential for Excursions
To determine if the facility discharge was expected to causeor havethe reasonablepotential to causethe CMC, CCC,or RACto be exceeded in the receiving water, the maximum receiving water concentration of eachpollutant wasfirst compared to the appropriate receiving water criterion. If the criteria were exceeded,then this wasconsidered evidence that awater qualitybasedlimitation mustbedeveloped.
Maximum expected concentrations were calculated using the averageeffluent flow, maximum effluent concentrations, background receiving water concentrations, and the relevant receivingwaterflow: the 1Q10fortheCMC,the 7Q10fortheCCC,or the harmonic meanforthe RAC.Thebackground receivingwater concentrations for total recoverable metalswere obtained from STORET data: Lead 1.6μg/l Copper 4.8μg/l

Nickel 13.2μg/l The maximum effluent concentration was estimated using the statisticalapproach inChapter3.Therewere 12concentrations of eachmetal reported inthe DMRs. Forlead,theseconcentrations hadamaximum valueof423μg/l, anarithmetic meanof258μg/ I, an arithmetic standard deviation of 74, and an arithmetic coefficient of variation of 74/258, or 0.3. This coefficient of variation andthe number ofobservationsdetermined which multiplier was selectedfrom Table 3-1. In this case,the multiplier valuefor 12observationsand aCVof0.3wasinterpolated from thevaluesfor 12observationsand CVsof0.2 and 0.4. The99th percentile multiplier wasestimatedto be1.7. Similarcalculations were conducted for copper (multiplier of 2.8) and nickel (multiplierof3.7).
130The receiving water concentration for lead for comparison with the CCC was calculated using data from Table 7-1:

C = I(1.7 x423 us/l x 0.034 cfs) + (1.6 us/l x 13 cfsjj (0.034 cfs+ 13 cfs)

= 3.5 pg/l where 13cfs = the receiving water flow at 7410 0.034 cfs = the mean effluent flow 423 ug/l = the maximum effluent concentration 1.7 = the statistical effluent multiplier to estimate the 99th percentile concentration 1.6 ug/l = the background receiving water concentration.

The value of the calculated receiving water concentration, 3.5 ug/l, was lessthan the chronic water quality standard of 9.1 Pg/l for lead, and therefore there isno reasonable potential for the CCC to be exceeded. Using the effluent data presented inTable 7-1, the receiving water concentration iscompared to the CMC as:
C = I(1.7 x423 us/l x 0.034 cfs)+ (1.6 us/l x 10.1 cfs)] (0.034 cfs+ 10.1 cfs)

= 4.0 fig/l

where 10.1 isthe receiving water 1QlO flow and the other values are identical to those for the CCC comparison. The resulting concentration of4.0 ug/l was lessthan the acute standard of 234 pg/l for lead. There isno reasonable potential for the CMC to be exceeded.

For human health criterion evaluation, the receiving water concentration for compared to the RACwas calculated as:
C = r(l.7 x 423 us/l x 0.034 cfs) + (1.6 us/l x 38 cfsIJ (0.034 cfs+ 38 cfs)

= 2.2 ug/l

where 38 cfs isthe harmonic mean flow and other values are the same asabove. This value was lessthan the human heath criteria value of SOPg/l for lead, sothere isno reasonable potential for the RACto be exceeded.

Similar calculations were done for copper and nickel:

Copper

ccc CMC

Nickel

ccc CMC RAC Criterion Receiving Water cPg/l) Concentration @g/l)

17.1 22.0 25.7 26.9

188 15.9 1,647 16.6 13.4 14.1 The effluent characterization showed the reasonable potential for excursions above the CCC for copper and above the RAC for nickel. Therefore, permit limits are necessary for these two pollutants.



### 7.2.3 E#oont Chwacto?lzotlonfarmlo ERhnwtrO%iCifJ’ Whole effluent toxicity also was evaluated since there was a potential for excursions above the narrative water quality criterion due to the combination of effluent toxicants with other toxicants inthe receiving water and in the effluent but below the detection level. The procedures used below follow those presented schematically in Figure 3-2, Chapter 3. Step 1: Dilution Determination

The initial dilution determination was used to establish the types of toxicity tests that are conducted to characterize the effluent. The dilution at the low-flow characteristics for the facility is the following:

At the 7Q10, dilution = (0.034 cfs+ 13 cfs)/0.034 cfs

= 383

At the 1Ql 0, dilution = (0.034 cfs+ 10.1 cfs)/O.O34 cfs

= 298.

Step 2: Conduct Toxicity Testing

EPA recommends that a discharger having a dilution between 100 and 1,000 be required to conduct either chronic or acute toxicity testing. The permitting authority decided to require chronic testing but required the permittee to report the test results at the 48-hour endpoint so that acute toxicity could be measured. One year before the permit was due to expire, the permitting authority requested, under the authority of the Clean Water Act (CWA) Section 308, that the permittee test hiseffluent for toxicity to provide effluent information in order to write the next NPDES permit. In this case, the permitting authority specified that the discharger submit quarterly chronic toxicity data for 1year using the EPAtoxicity tests for Selenostrvm, Cerioduphnia, and Pimephales. The permitting authority also specified that upstream ambient water be used asthe diluent in the tests soasto allow the tests to measure additive effects from ambient toxics. In response to the Section 308 request, the discharger submitted the whole effluent toxicity data shown in Table 7-l. Step 3: Determine Reasonable Potential for Excursions

The State interprets its narrative criteria for whole effluent toxicity to require that the technical support document recommendations of 0.3 TU, and 1.OTU, be used as numeric values for acute and chronic toxicity, respectively. In accordance with the State standards, the CMC applies under the 1Ql 0 flow and the CCC applies under the 7QlO flow.

The determination of exceedance of the CMC or the CCC was simplified by the way in which the tests were conducted. Since the upstream ambient water was used asadiluent, the test results

131already include an assessment of contributions from background toxicity. Therefore, the upstream receiving water concentration was setto zero.
The maximum effluent concentration was again estimated by using the statistical approach in Chapter 3. Asshown inTable 7- 1, there were four observations of whole effluent toxicity. Based on the guidance of Box 3-4, these are insufficient to determine the CVaccurately; therefore, the default CV of 0.6 was used. The effluent multiplier of 4.7 was obtained from Table 3-l using the number of observations, the CV, and the 99percent probability basis.

The receiving water concentration for chronic toxicity for comparison with the CCC was calculated using data from Table 7-l :
C = (4.7 x 20 TU, x 0.034 cfs) + (0TU, x 13 cfs)] (0.034 cfs+ 13 cfs)

= 0.25 TU,

where

13cfs = the receiving water flow at 7410 0.034 cfs = the mean effluent flow 4.7 = the statistical effluent multiplier 20 TU, = the maximum effluent concentration.

The value of the calculated receiving water concentration, 0.25 TU,, was lessthan the chronic water quality standard of 1.OTU,, and therefore there is no reasonable potential for the CCC to be exceeded.

To calculate the receiving water concentration for acute toxicity, the permitting authority first converted the chronic toxicity data into equivalent acute toxicity units by applying the acute-tochronic ratio (ACR) of 5 obtained from the monitoring data. The receiving water concentration for acute toxicity was then calculated:

C = [(4.7 x 20 TU, / 5ACRx 0.034 cfs) + (0TU, x 10.1 cfs)] (0.034 cfs+ 10.1 cfs)

= 0.06 TU,

where 10.1 cfs isthe receiving water flow at 1Ql 0, 5 isthe acute to chronic ratio, and the other values are the same asabove. The calculated value of 0.06 TU, is below the criterion of 0.3 TU,; therefore, there is no reasonable potential for the CMC to be exceeded. Sincethere was no reasonable potential for exceedances above either the acute or chronic criterion, permit limits were not developed for whole effluent toxicity.



## 7.2.4 &!temhe wisstaa Aw8tl~ The wasteload allocation @VIA) was used to determine the level of effluent concentration that would comply with water quality standards inthe receiving waters. AWlA will only be determined for those parameters that have a reasonable potential to cause exceedances of water quality standards. Therefore, WLAs were determined for copper and nickel. Since there was no reasonable potential for excursions above the CMC or CCC for nickel, only the WLA for human health was calculated.

To determine WLAs, the numeric criteria in the water quality standards and background concentrations were used to calculate effluent concentrations that would result in compliance with those standards. The calculation of WlAs used receiving water flows that were appropriate to each standard: chronic WLAs were calculated using the 7410 flow, acute WlAs were calculated using the 1QlO flow, and human health WLAs were calculated using the harmonic mean flow. Since the effluent was mixed rapidly by the multiport diffuser, the complete mix equation was used: 

## MA =WQCx(Q +QJ-Q&I/Q,

where

Qe = the effluent flow QS = the receiving water flow

cs = the background receiving water concentration WQC = the water quality criterion.

The chronic and acute WLA for copper were calculated at the 7410 and 1Ql 0flows, respectively:
WLA, = [17.1 ug/l x (0.034 cfs+ 13 cfs) - 13 cfsx 4.8 pg/l] / 0.034 cfs

= 4,720 pg/l

WLAa = [25.7 ug/l x (0.034 cfs+ 10.1 cfs) - 10.1 cfsx 4.8 pg/l] IO.034 cfs

= 6,234 pg/l.

The human health WIA for nickel was calculated at the harmonic
mean flow:
w,m/,h = [13.4 pg/l x (0.034 cfs+ 38 cfs)- 38 cfsx 13.2 ug/l / 0.034 cfs

= 237 ug/l.



## 7.2.5 DsrelbpPennIlUdfs Permit limits were developed using asteady-state, two-value WL4 model asdescribed in Box 5-2, Chapter 5. Values for constants were obtained from Table 5-2, Chapter 5. Step 1: Calculate LTA (note: this isStep 2 in Box 5-2)

The chronic long-term average (LTA) for copper was calculated using the following formula:

LTh = WLA x exp [OS o 2-z o]

= 4,720 ug/l x 0.440

= 2,077 pg/l

where values of exp [ 0.5 o2 -z ou ] are presented in Table S-1 (see Chapter 5). The CV of 0.8 was used, and following the

132guidance of Section 5.5.4, the z value for the 99th occurrence With a CV of 0.6, four samples per month for sampling, and a probability was used. 99th percentile used for the MDL, the factor is 1.64:

The acute LTA for copper was calculated, again using the 99th percentile occurrence probability values from Table 5-1 as the multiplier: MDL = AMLx1.64

= 237 Pg/l x 1.64

= 389 Pg/l.
LTAa = 6,234 Pg/l x 0.249

= 1,552 Pg/l. 

### lines The LTA for nickel human health permitting isconsidered to be the same as the WLA because the 70-year averaging period is used for human health evaluations (see Section 5.4.4). The LTA is calculated as: LTAf, = WL$,

= 237 Pgg/l. The NPDES regulations require that effluent limits require treatment characteristic of the appropriate treatment technology and also achieve water quality standards. Ifwater quality-based limits are more stringent than BAT limits, then the water quality-based limits become the basis for the effluent limits. Conversely, if the treatment technology (BAT) limits are more stringent, then they become the basis of the limits.

Step 2: Determine the More Limiting LTA

The limiting LTA for each pollutant was the minimum of the chronic, acute and human health LTA. The limiting LTAvalue was used in the next step to calculate maximum daily limits and average monthly limits. The limiting LTAfor copper was found to be the acute LTA (1,552 kg/l) and the limiting LTAfor nickel was found to be the human health LTA (237 ug/l). The comparison between the water quality-based and technology-based effluent limits are shown below. The more stringent limits are different for different pollutants: for nickel, water quality-based limits are more stringent whereas for copper, the BAT limits are the more stringent.

Coowr Nickel

Step 3: Calculate Maximum Daily and Average Monthly Limits

The maximum daily limit (MDL) for copper was calculated using the expression:

MDL = LTAx exp [z o -0.5 a21

= 1,552 ug/l x 4.01

= 6,224 ug/l Water quality MDL 6,224 389 AML 2,716 237

BAT MDL 3,380 3,980 AML 2,070 2,380

Limit to use MDL 3,380 389 AMC 2,070 237

where the appropriate value for exp [zo -0.5 02] was taken from Tabfe S-2 using the row with the CV for copper (0.8) and the column for the 99th percentile probability basis. In accordance with NPDES regulations, the effluent limits were expressed in the permit asmass (pounds per day) by multiplying the concentrations above by the effluent flow of 0.034 cfsand the conversion factor of 5.394:

The average monthly limit (AML) for copper was calculated using the expression:

AML = LTAx exp [zon -0.50,-,~]

= 1,552 fig/l x 1.75

= 2,716 ug/l MDL AML Copper (lb/d)

0.62 0.38 Nickel (lb/d)

0.071 0.043

where the value for exp [zCT,, -0.5 o,~] was taken from Table 5- 2 and, for this case, the number of samples per month was four. following the recommendations in Section 5.5.4, the zvalue for the 95th percentile probability basiswas used.

The effluent limits for nickel were determined by using the recommendations in Section 5.4.4, Chapter 5. The AML was considered to be identical to the W&, whereas the MDL was calculated from the AML by using the appropriate multiplier factor in Table 5-3. 

### 7.2.7 Cm#ariingD~lindtDsveloprnenttet~ds Permit limits for copper alsowere developed using a Monte Carlo simulation in order to compare the results to the permit limits derived from the two-value, steady-state model. A Monte Carlo simulation was used to generate receiving water concentrations to determine the effluent LTAfor each of the pollutants such that the water criteria are achieved at the required frequency in the water quality standards.

133Monte Carlo simulation used the same completely mixed dilution equation aswas used for the steady state calculation:

C = (Q&e +

### QsWQ +

### 9s)

where C isthe receiving water concentration (in Pg/l); C, and C, are the effluent concentration and the background concentration of the receiving water, respectively (in Pg/l); and Qe and Qsand effluent and receiving water flows, respectively (in cfs). Effluent flows were held constant at the mean effluent flow, and river flows were read from acomputer file containing 60 years of daily flow data provided by the U.S. Geological Survey. The effluent concentrations were characterized by a lognormally distributed random variate. The random variate had acoefficient ofvariation that matched the CV of the pollutant in the effluent.

The Monte Carlo simulation was run using 22,276 iterations. Once 22,276 receiving water concentrations had been calculated, receiving water concentrations were sorted, highest first. The 20th value (corresponding to the maximum concentration expected for 1day in 3years) was compared with the appropriate criterion. The 1-day in 3-year return frequency isrecommended by EPAfor criteria (see Chapter 2). lfthis value was higher than the criterion, the effluent LTA was reduced, and a new set of 22,276 numbers was generated. When the receiving water concentration of the 20th value was just under the water quality criterion (and the 19th value was just over the same value), then the LTAeffluent concentration generating these results was sufficient to achieve the water quality criterion; this LTAwas then used in permit limit determinations.

Forchronic criteria, 4-day average concentrations were generated by taking the 4-day running average of modeled daily concentrations. The recurrence concentration was calculated in the same way as the l-day calculations described in the previous paragraph. Calculations were not made for the human health criterion.

The permit limits were calculated according to the procedures given in Box S-3. Each LTAwas multiplied by the 99th percentile multiplier from Table 5-3 for the MDL, and by the 95th percentile multiplier from Table 5-3 for the AML. For the AML, the same number of samples were used for the steady state and Monte Carlo permit limits (n=4). Thus, the resulting permit limits are directly comparable. The results ofthe Monte Carlo simulation for copper compared to the steady state calculations in units of micrograms/liter are shown below:

Monte Carlo Steady State Maximum Average Daily Monthly
8,618 3,761 6,224 2,716



## 7.3 CASE2 POTWDISCIIASE

The second example is01’3 fictitious POlVV 

### thatdischarges to the same reach asthe Jaybird C’orporation. The NPDES permit for this facility also isup for reissuance. The example highlights the useof background receiving water concentrations, and demonstrates the differences between industrial and POTW permit limits. In developing permit limits for the POlW in this example, the potential impacts from the Jaybird Corporation discharge were considered in the use of background receiving water concentrations. The interrelationships between the two facilities are discussed explicitly in Section 7.4.



### 7.3.1 6l?nmai slle Ddscripuon %miIThe Locapunct River receives discharges from a POlW serving the city of Auburn, a small city of about 10,000 people. The POlW treats a mixture of household and industrial waste with an activated sludge process. The mean effluent flow from the POTW is 1.23 cfs. The POTW has no pretreatment program, but the municipality generally is aware of the small industries that are indirect dischargers because of research conducted by a local university. Generally, the plant iswell operated.



### 7.3.2 Em& C~c~~oll for !qt?cmc clbidmk The permitting authority’s approach for determining which pollutants cause, have the reasonable potential to cause, or contribute to excursions above water quality standards applies to POTWs aswell asindustries. The authority used the procedures described for the jaybird Corporation inthe evaluation ofthe Auburn POTW. Step 1: Identify Pollutants of Concern

At the time of the last permit issuance, there was evidence of a number of toxic pollutants in the POTW’s effluent, including copper, chlorine, and ammonia. These pollutants had monitoring requirements in the previous permit. Because there were metals in the effluent and, due to the industries discharging into the POTW sewer system, the permitting authority requested the POTW to conduct a complete priority pollutant scan of the effluent. The data received following the Section 308 letter request indicated that the concentrations of all priority pollutants except copper were below detection limits. The POTW’s primary toxic pollutants of concern were copper, chlorine, and ammonia (see Table 7-2).

Step 2: Determine RAC, CMC, or CCC for Pollutants of Concern
Asdescribed in the example of the industrial discharge, the water quality standards include numeric criteria for copper. The State also has adopted a numeric criterion for ammonia that is a function of the river 85th percentile pl-l and temperature; these values are 8.25”C and 25’C, respectively. Finally, the State interprets its narrative criterion of “no toxics in toxic amounts” to require useof the federal water quality criteria in the absence of a numeric state criterion. Asa result, the permitting authority uses the federal criteria for chlorine. The applicable water quality criteria for the river are asfollows:

Copper Chlorine Ammonia ccc W/l)

17.1 11 540 CMC @3/l) 25.7

19 4,000

134Table 7-2. Effluent Data for the Auburn POlW

n

1 268 185 11,009 2 115 301 13,025 3 228 881 12,201 4 59 372 24,548 5 53 245 9,700 6 213 244 15,645 7 68 123 21,358 8 200 343 3,976 9 262 153 22,307 10 519 448 7,427 11 53 1,022 11,834 12 474 347 8,430 13 115 130 4,382 14 2.59 128 9,330 15 404 271 6,137 16 57 451 6,448 17 101 701 37,772 18 187 582 14,307 19 103 178 16,848 20 76 436 28,205 21 198 347 12,119 22 265 475 11,778 23 60 153 3,109 24 112 268 4,474 Mean 185 366 13,182 SD 133 235 8,491 cv 0.7 0.6 0.6 Max 519 1,022 37,772 Min 52.6 123 3,109 Copper

INI Chlorine Ammonia Toxicity l-u‘

1.5 0.6 0.4 2 1

Source: DMR data for chemicals; 308 request for whole effluent toxicity. Notes: Metals astotal recoverable; toxicity in toxic units (1001NOEC). The results are the highest toxic units for any of the test organisms used.

Step 3: Determine Dilution for Aquatic Life and Human Health Impacts

The State water quality standards requires that compliance with water quality criteria be achieved at the edge of the mixing zone. The standards specify the minimum dilution at which the criteria apply. These are the 7410 flow for the CCC, the 1Ql 0 flow for the CMC, and the harmonic mean flow for human health criteria (RAC). The U.S. Geological Survey operates a gaging station on the river. The Row statistics were calculated 

### usingthedata from this station:

l Harmonic mean flow = 38.0 cfs

l 7410 flow = 13.0 cfs

l 1Q10flow=10.1 cfs.

The POTW islocated at a bend ofthe river where mixing israpid. Therefore, the permitting authority used the complete mixing equation to calculate the receiving water concentrations. This is the same equation used for the industrial example. Step 4: Determine Reasonable Potential for Excursions

The determination of possible 

### exceedances in the CMC or CCC was based on acalculation of the maximum receiving water concentration of each pollutant, followed by a comparison to the appropriate receiving water criterion. The calculation of the maximum receiving water concentrations were made using the statistical estimate of the 99th percentile concentration of each pollutant in the effluent, the same flow used in the industrial example, and considered background receiving water concentrations of: Copper 4.8 pg/l Chlorine 0 w/l Ammonia 120 fig/l.

The maximum effluent concentration was estimated using the statistical approach 

### in Chapter 3. There were 24 concentrations of each chemical reported in the DMRs. For copper, these concentrations had a maximum value of 519 Pg/l, an arithmetic mean of 185 pg/l, an arithmetic standard deviation of 133, and an arithmetic coefficient of variation of 133/l 85, or 0.7. The multiplier was calculated to be 2.4 based on the CV of 0.7, 24 observations, and a99percent confidence level (seeSection 3.3.2). Similar calculations were conducted for chlorine (multiplier of 2.2) and ammonia (multiplier of 2.2).

The receiving water concentrations for each pollutant were calculated. An example calculation for the comparison of copper to the CCC isshown below:

C = J(2.4 x 519 us/l x 1.23 cfs) + (4.8 us/l x 13 cfs)l (1.23 cfs+ 13 cfs)

= 112pg/l where

519 pg/l = the maximum measured effluent concentration 2.4 = the statistical multiplier 1.23 cfs = the average effluent flow 4.8 Pg/l = the upstream receiving water concentration 13cfs = the 7410 flow.

The maximum receiving water concentrations for comparison to applicable standards for all pollutants were calculated to be:

Copper ccc CMC

Chlorine ccc CMC

Ammonia ccc CMC Criterion w-II0

17.1 25.7

11 19

540 4,000 Receiving Water Concentration @g/l)

112 140

194 244

7,292 9,128

135

### ---

The effluent characterization showed the reasonable potential for excursions above the CCC and CMC for copper, chlorine, and ammonia. Therefore, permit limits were developed for these pollutants.



### 7.3.3 Eiflumt B fw ml@ Ef&rsntfoxicit~’

Step 1: Dilution Determination

The initial dilution determination was used to establish the types of toxicity tests that must be conducted to characterize the effluent. The dilution at the low flow characteristics for the facility is the following:

At the 7410, dilution = (1.23 cfs+ 13 cfs)/l.23 cfs

= 11.6

At the lQ10, dilution = (1.23 cfs+ 10.1 cfs)/l.23 cfs

= 9.2.

Step 2: Conduct Toxicity Testing

EPArecommends that adischarger having adilution lessthan 100 be required to conduct chronic testing. The permitting authority requested through a Section 308 letter that the POTW provide quarterly chronic toxicity data for the year prior to permit reissuance. Tests using Selenastrum, Ceriodaphnio, and Pimephaies were required. The permitting authority also required the permittee to report the test results at the 48-hour endpoint sothat acute toxicity also could be measured. Table 7-2 summarizes the results of the whole effluent toxicity testing.

Step 3: Determine Reasonable Potential for Excursions

As explained in the industrial example, the State interprets its narrative criteria for whole effluent toxicity to require that the technical support document recommendations of0.3 TU, and 1.O Tu, be used as numeric values for acute and chronic toxicity, respectively. In accordance with the State standards, the CMC applies under the lQ10 flow and the CCC applies under the 7410 flow.

The reasonable potential determination of exceedance of the CMC or the CCC was conducted in the same way asdescribed in the industrial example. Upstream ambient water was used as a diluent to assesscontributions directly from background toxicity; therefore, the upstream receiving water concentration was set to zero. The maximum effluent concentration was again estimated by using the statistical approach in Chapter 3. For the same reasons aswere expressed in the industrial example, a multiplier of 4.7 was used.

The receiving water concentration for chronic toxicity for comparison with the CCC was calculated using data from Table 7-2:

C = (4.7 x 2TU, x 1.23 cfs) + (0 TU, x 13 cfs) (1.23&+ 13cfs)

= 0.8TUc where 13 cfs = the receiving water flow at 7410 1.23 cfs= the mean effluent flow 4.7 = the statistical effluent multiplier 4 TU, = the maximum effluent concentration.

The value of the calculated receiving water concentration, 0.8 TU,, islessthan the chronic water quality standard of 1.OTU,, and therefore there is no reasonable potential for the CCC to be exceeded.

To calculate the receiving water concentration for acute toxicity, the permitting authority first converted the chronic toxicity data into equivalent acute toxicity units by applying the ACR of 2 obtained from the monitoring data. The receiving water concentration for acute toxicity was then calculated:

C= [(4.7x2TUc/2ACRx1.23cfs)+(OTU,x10.1 cfs)] (1.23 cfs+ 10.1 cfs)

= 0.5 TU,

where 10.1 cfs isthe receiving water flow at 1Ql 0, 2 isthe acute to chronic ratio, and the other values are the same asabove. The calculated value of0.5 TU, isgreater than the criterion of0.3 TU,, Therefore, there is reasonable potential for the CMC to be exceeded and permit limits were developed for whole effluent toxicity.



### 7.3.4 lhthmnim wasteloadAll&iWLAsfor chemicals and whole effluent toxicity were determined using information on the available dilution at the edge of the mixing zone. The calculation ofWIA using the steady-state model was described in Section 7.2.4. The WLAsfor the POTW using the equation discussed in Section 7.2.4 are:

wLAa WLA, Toxicity Copper Chlorine Ammonia t-w WI) WD (WI/l) 2.8 197 175 35,860 11.6 147 127 4,979



### 7.3.5 ik7nT&pPlwnlltlhMs The permit limit development process described in Box 5-2, Chapter 5was applied to all pollutants. This process isidentical to that explained in Section 7.2.5 except that (1) the WLA for acute toxicity needs to be expressed in equivalent chronic toxic units by multiplying by the ACR of 2, and (2) daily sampling of chlorine is required in the permit. The calculated LTAand permit limits are:

LTA, LW MDL AML Toxicity Copper Chlorine Ammonia TUC 019/l) &l/b &l/l) 1.8 55.4 56.2 11,511 6.1 70.7 66.9 2,625 5.6 197 175 8,162 2.8 91 87 4,067

136

### 7.3.6 llotmdning andExpssia6 Llre Gontrollin6Effluent llndt The treatment technology for POTWs issecondary treatment and is characterized by effluent limits for biochemical oxygen demand, total suspended solids, and pti. There are no BATlimits for toxics for POlWs, sothere was no need to compare these water quality-based limits with other limits to determine which were more stringent.

The permitting authority decided to useacute toxicity tests rather than chronic tests to measure compliance with the toxicity effluent limits. The appropriate effluent limits in terms of TU, were calculated by dividing the above calculation for TU, by the ACRof 2that was obtained from effluent monitoring.

In accordance with NPDES regulations, the effluent limits for chemicals were expressed inthe permit asmass (pounds per day) by multiplying the concentrations above by the effluent flow of 1.23 cfs and the conversion factor of 5.394. Because there is no equivalent mass based unit for toxicity, toxicity mass limits are impractical under the regulation.

MDL AML Toxicity Copper Chlorine Ammonia TUa (lb/d) (Ib/d) (lb/d) 2.8 1.31 1 .16 54.2 1.4 0.64 0.58 27.0



### 7.3.7 ~/ng DhYwentlimit &?vetopnn?nt Moth& Permit limits alsowere developed using a Monte Carlo simulation to compare the results to the steady-state permit limits. AMonte Carlo simulation was used to generate receiving water concentrations for determining the appropriate LTAfor each of the pollutants. The methodology forthe Monte Carlo simulation ispresented in Section 7.2.7. The results for this case are presented below.

MOLs in TU, and ug/l Toxicity Copper Chlorine Ammonia Monte Carlo 3.9 264 249 9,657 Steady State 2.8 197 175 8,162

AMLs in TU, and pg/l Toxicity Copper Chlorine Ammonia Monte Carlo 2.7 171 170 6,614 Steady State 1.4 91 87 4,067



## 7.4 CASE 3: MDLTlPlEDlSCHARDES INTO THE SAME REACH

Permit development for water quality-based toxics control has been illustrated for two single dischargers. This process increases in complexity in cases of multiple dischargers into a reach. The development of permit limits for multiple dischargers isbased on the degradation in water quality resulting from the combined discharges, the development oftotal maximum daily loads (TMDls) for the river reach before generating WI& and the allocation of discharges to each discharger. The following example describes the permit development process when two dischargers release effluent into the same reach of a river. The dischargers are the Jaybird manufacturing plant described in Case 1and the Auburn POTW described in Case 2. These facilities discharge into the Locapunct River, whose flow characteristics previously were described.



### 7.4.1 EffluentChamcterbafion The major differences in the effluent characterization for one facility and for multiple facilities isto identify those pollutants that are common to more than one facility, and to determine whether the combined discharges cause or are likely to cause water quality standards excursions. Step 1: Identify Pollutants of Concern

Based on the data in Form 2C, the DMRs from the laybird Corporation and the data in the DMRs and Section 308 request from the Auburn POTW, the permitting authority found two contaminants common to both discharges: copper and whole effluent toxicity. Lead and nickel were found to be a problem at the Jaybird Corporation, but since there were no complicating discharges from the POTW, itwas dealt with asapollutant only at the metal finishing facility. Similarly, chlorine and ammonia were discharged solely by the POTW, so itwas not necessary to provide effluent limits for the metal finishing facility for these chemicals. Step 2: Determine the CMC and CCC for Pollutants of Concern
The numerical standards adopted by the State already have been presented. The relevant values for copper and whole effluent toxicity are:

Copper Toxicity ccc CMC 17.1 f.lg/l 25.7 ug/l 1.OTU, 0.3 Tu,

Step 3: Determine Dilution for Aquatic Lie and Human Health Impacts

Since this example isconcerned with potential excursions above standards resulting from the collective discharge oftwo dischargers,the calculation ofdilution includes the combined effluent flow from both facilities. The combined dilution can be characterized by the complete mixing equation:

C= (&I Qel +

### C,zQez+

### CsQsMQet+Qe2 +

### Qs)

where

Qel and Qez = the flows of the two facilities C,l and Cc2 = the effluent concentrations ofthe two facilities CS = the upstream receiving water concentration 

### Qs = the receiving water flow.

137Step 4: Determine Reasonable Potential for Excursions

To determine ifthe CMC or CCC were exceeded asaresult ofthe combined discharges into the river, the receiving water concentration of each 

### pollutantwascalculatedand compared to the appropriate criterion. The receiving water concentration calculation was based on the maximum value of the effluent concentralions (obtained from effluent data and multiplied by the appropriate statistical factor), average effluent flows, background receiving water concentrations, and appropriate river flows. All this information has been presented previously in the separate examples. The following results were obtained:

Copper

ccc CMC
Toxicity ccc CMC Criterion 01gA)

17.1 25.7

1.0 0.3 Receiving Water Concentration @s/l)

156 194

0.57 0.45

These calculations demonstrated exceedances of the copper CCC and CMC criteria and the toxicity CMC criterion. Permit limits were required.



### 7.4.2 TIII#LsstnlHZ& WLAs were calculated to develop permit limits. WLAs for each discharger and chemical were based on calculated TMDLs, the total load to the Locapunct River that would not result in water quality standards exceedances. TMDLs are comprised of a load allocation for nonpoint sources, WlAs for point sources, and, if required by the State, a reserve capacity. TMDLs are further described in Section 4.2, Chapter 4. Step 1: Calculate TMDL

The first step in developing individual WlAs for the two dischargerswas to develop TMDLs for each pollutant of concern. TMDLs were developed in the same way as an individual WLA with the total load of a pollutant from the two dischargers being considered asa single discharge.

The calculation of TMDLs used the following formula: TMDL=WQSx(Qt+Q,)

where

WQS = the water quality standard 

## Qt = the combined flow of both effluents 

## QS = the appropriate receiving water flow.

The acute copper TMDL was calculated by using the data presented in the previous hyo examples as: TMDL = 25.7 lg/l x (0.034 cfs+ 1.23 cfs+ 10.1 cfs)

= 292 pg-&/I

where

25.7 pg/l = theCMC 0.034 cfsand 1.23 cfs = the average effluent flows 10.1 = the 1QlO.

Similar calculations were made for chronic copper and acute toxicity. ATMDL was not calculated for chronic toxicity because the information presented in Chapter 1 indicates that chronic toxicity does not demonstrate additivity. The results are summarized below.



### Copper bg-cfs/l) Toxicity (TU,-&/I) Total Maximum Daily Loads Chronic Acute 244 292 NA 3.4

Step 2: Develop WlAs

The State had adopted an approach into the water quality management plan that described how WLASwere to be calculated. The approach required that existing upstream concentrations be used to determine the load allocation part of the TMDL and that 10 percent of the TMDL had to be reserved and unavailable for allocation. The remainder of the TMDL could be apportioned to point sources in the WLA.

The permitting authority decided to allocate the wasteloads based on the proportion of the existing load of each parameter that was attributed to each of the existing discharges. Based on the information shown inTables 7-l and 7-2 and the average effluent flows, the pollutant loads from each facility are shown below.

Parameter COPper @g-ds/l) Toxicity 0%6s) Auburn POTW Jaybird Corporation Load Proportion Load Proportion

227.6 0.77 66.1 0.23

1.23 0.90 0.14 0.10

Individual WLAs were then determined using the following equation:

WfA = (TMDL - LA- 10% TMDL) x proportion/Q

where the chronic TMDL was used to determine the chronic WLA, and the acute TMDL was used to determine the acute WLA for each facility. The WLAsfor each pollutant and for each facility are presented on the following page.

138Jaybird Copper 6.0) Toxicity UU,) Acute WLA

134 1,450 2.2 9.0 Chronic WLA

98.4 1,063 NA NA



### 7.4.3 PfmIdtumnlhvf~ Once the WLAs had been determined, permit limit development proceeded as in the previous examples. LTAs were calculated from the WLAS,and the limiting LTAwas selected for calculating permit limits. Forthe metal finisher, where BAT limits were more restrictive than the water quality-based limits, the BAT limits applied. For the POTW, permit limits for toxic materials were required only to prevent exceedances ofwater quality standards. This process issummarized below. Step 1: Calculate LTAs

The LTA was calculated for each discharger and pollutant as described in Step 2, Box 5-2, Chapter 5; the LTAs are shown below.

Parameter Copper (c1gN Toxicity (TU,) Acute LTA POIW Jaybird 37.7 361 0.71 2.9 Chronic LTA POW Jaybird 47.3 468 NA NA Step 2: Determine the More Lmiting LTA

The minimum LTA was used to calculate MDLs and AMLs. The acute LTAwas the lower LTAfor both pollutants. Step 3: Calculate the Maximum Daily and Average Monthly Limits

The MDL and AML were calculated as described in Box 5-2, Chapter 5: Average Monthly Limit Maximum Daily Limit Parameter POTW Jaybird POTW jaybird Copper @g/l) 62 632 134 1,448 Toxicity (TU,) 1.1 4.5 2.2 9.0

Step 4: Express the Limits

The final step isto compare the water quality-based limits to the BAT limits to ensure that the more restrictive of the two are used, and to express the copper limits in terms of mass. The copper water quality-based limits for Jaybird Corporation are lower than the BAT ones (see Section 7.2.6). Therefore, the water qualitybased limits are required by the permit. Inaddition, the limits are lower than those calculated when only one of the facilities were considered. The final permit limits are listed below.
Average Monthly Limit Maximum Daily Limit Parameter POlw Jaybird Polw Jaybird 

### Copper (lb/d) 0.41 0.12 0.89 0.27 Toxicity (TU,) 1.l 4.5 2.2 9.0

139Acute toxicity endpoints (ATEs) lethal concentration (LC) 4 Acute toxicity testing 59 Acute-chronic ratio (ACR) 17 Additivity 24 Allowable Effluent Concentration Distribution 82 Ambient toxicity testing 61 Ambient-induced mixing 77 lateral dispersion coefficient 77 shear velocity 77 Amelia River 68 Ames test 25 Analytical considerations for chemicals 65 Antidegradation policy 29 Aquatic community 18 Aquatic Lie Protection 34 ARM 84

BAF 38 Bioaccumulation 37, 38, 72 Bioaccumulation consideration 38 Bioconcentration 38, 64 Biocriteria 41,42 Biological assessment/bioassessment 18, 20 Biological criteria biological integrity 1, 18 Biological surveylbiosurvey 18, 19

Calculations CCC for toxicity 85 CMC for toxicity 85 Concentration (multiple dischargers) 86 Concentration (nonconservative pollutant) 87 Harmonic mean flow 88 Lateral dispersion coefficient 77 Carcinogenic&y 25 Carcinogens 68 Carcinogens, calculating l?ACs 40 CCC 34,85 CCC. SeeCriterion continuous concentration 79, 85 Center for Exposure Assessment Modeling (CEAM) 73 Chronic toxicity endpoints effective concentration 4 lowest observed effect concentration 4
no observed effect concentration 4 Chronic toxicity testing 59 Clean Water Act (CWA) 1, 67 CMC 34, 71, 85 CMC. 71 Coefficient of variation (CV) 95 in permit limit derivation 105 Completely mixed discharge-receiving water 

### situations Complex Effluent Toxicity Testing Program (CElTP) 7, 9 Compliance monitoring 123 discharge monitoring report/quality assurance 124 inspections 124 self-monitoring report 123 Compliance problems 53 Concentration flow distance 77 Continuous Simulation 80 CORMIXl 76 Criterion continuous concentration (CCC) 48 Criterion maximum concentration (CMC) 48, 71, 85 Critical conditions 67 Critical design periods estuaries and coastal bays 74
oceans 74 rivers and run-of-river reservoirs 73 lakes, reservoirs 73
Design periods. SeeCritical design periods Designated use 54 Detection level minimum level 111 practical quantitation limit 112 Detection levels 111 Determining the need for a limit statistical approach 56 when isa chemical-specific limit sufficient? 62 with effluent data 55 without effluent data 50 Dilution 52-53, 61 Dilution determination 58, 63 Discharge monitoring reports 54 Discharge-Induced Mixing 75 Duration 31-32 Duration for single chemicals and WET 35 Dye study 51, 58 Dynamic modeling. See Modeling Modeling techniques; Models 76, 78, 79 DYNHYD4 89 DYNTOX 83,84

Effluent bioconcentration evaluation 42, 64-65 Effluent characterization 47 addressing uncertainty in 56 for aquatic life effects 48 for human health effects 48, 62
or multiple dischargers 60-61 for specific chemicals 61-63 for whole effluent toxicity 56-60 process 53, 63 78

141Effluent characterization (cont.) purpose 48 special considerations for marine and estuarine

systems 61 Effluent variability basic principles 93 Enforcement 125 enforcement discretion 125 enforcement mechanisms 125 whole effluent toxicity enforcement 124, 125 EXAMS-II 84 Excursion above CMC or CCC 60 Excursions above ambient criteria 50 Expressing limitations and developing monitoring require

ments 110 Expressing permit limits mass-based limit 110 maximum daily 96

FCM2 85 FCETS 85 Fishconsumption values 37 Fishable/swimmable 29 FLOSTAT 89 Food chain 87 Frequency 31, 32 Frequency for single chemicals and WET 36

CC/MS 64 Generating Effluent Data 56 Cenotoxic pollutants 25

Health effects 25 nonthreshold effects 25 threshold effects 25 HPLC 65 HSPF 84 Human exposure Background concentrations 37 drinking water ingestion 37 fish consumption 37 Human health criteria Ql l 39,40 RfD 39, 40 updating 38 Human health protection 25 Human health protection (WQC) 36 Human health/Human exposure 37
Implementation methods for state antidegradation policies Tier I 29 Tier II 30 Tier Ill (ONRWs) 30 Independent application 22, 31, 49 Integrated approach 1 bioassessment approach 1, 22 chemical-specific approach 1, 20 whole effluent approach 1,4, 21 Integrated RiskInformation System (IRIS) 38 Isopleths, concentration 72

LA. See Load allocation 67 Lateral dispersion coefficient 77 LC50 4, 57, 58, 71 Limits for metals 111 Load allocation 67 Lognormal Probabilistic Dilution Model 82 Long term average (LTA) 95
Magnitude 3 1, 32 Magnitude for single chemicals 34 Magnitude for whole-effluent toxicity 35 Magnitude, duration, and frequency (Criteria) 31, 32 Margin of safety 67 Marine and estuarine discharges 61 Marine and estuarine permitting 104 Maximum daily permit limits chronic toxicity 96 Metals 111 MINTEQA2 84,85 Mixing zone 58, 72 Mixing Zones 33 Modeling techniques continuous simulation 81 lognormal probabilistic dilution model 82 Monte Carlo simulation 81 steady state 78 Models CORMIXl 76 DYNHYD4 84 DYNTOX 84 EXAMS-II 84 FCM2 85 FCETS 85 FLOSTAT 89 HSPF 84 MINTEQA2 85 Mixing zone 70 PSY 78 SARAH2 85 Selection of 83 STORET 79 TOX14 84 UDKHDEN 77 ULINE 77 UMERGE 77 UOUTPLM 77 UPLUME 76, 77 WASP4 84

142Monte Carlo simulation 80, 81 Monticello Ecological Research Station (MERS) 2 Multiple source toxicity testing procedures 60-61 Multiple-source discharge 60-61

Narrative criteria 29 Noncarcinogens 89 NPDES program 1 Number of samples in permit limit derivation 105 Numeric criteria 29

Outfall design recommendations in lakes and reservoirs 73 in oceans 74 in rivers 73 multiport submerged 73 single-port submerged 73 surface discharge 73 Outstanding national resource waters (ONRWs) 30

Penalties 124 Permit documentation 110 Permit limit derivation 98 aquatic life protection 98 average monthly 96 average weekly 96 basic objective 96 detection levels 111 direct application of both the acute and

chronic WlAs 104 dynamic 101 human health protection 104-l 05 maximum daily 96 other approaches 103 selection of monitoring frequencies 113 single value steady state 102 two value steady state 98
use of aWLA asapermit limit 96-97 Pollution prevention 111 Potential for excursion above CMC or CCC 58 POlw 53 Precision 2, 11, 12 coefficient of variation (CV) 12 inter-laboratory precision 2, 11 intra-laboratory precision 11 variability 11 Priority toxic pollutants 30 Probability basis average monthly 110 daily maximum 110 in permit limit derivation 110 LTAforWlA 110 Quality assurance 12, 123 discharge monitoring report/quality assurance 124

Reasonable potential 48,49,50, 58
asatrigger 58 for multiple dischargers 60 for whole effluent toxicity 58 regulatory basis 49 with effluent data 50, 56 without effluent data 49 Receiving water concentration (RWC) 48 Reference ambient concentration (RAC) 48 Reference toxicants 12 Regulation requirements 4849 Reporting violations 126 to the public 126 to the regulatory agency 124 Return period 82 Rhodamine WT. SeeTracer (dye) studies 75

SARAH2 85 Screening protocol 53 Sediment 42,67 Sediment criteria 42 Shayler Run, Ohio 2 Single value wasteload allocations
use in permit limit derivation 102 Species sensitivity 59 Species sensitivity differences 16 Statistical considerations of effluent limits 105 changes in CV on limits 106 changes in CV on LTA 105 changes in monthly samples 105, 107 changes in probability basis on limits 105, 110 Statistical considerations of WLAS 96 Statistical distributions of effluent data lognormal (positively skewed) 95 normal (bell shaped) 95 STORET 79 TMDL. SeeTotal maximum daily load Total maximum daily load calculation of 78 margin of safety 67 Total maximum daily load (TMDL) 1, 67, 78 TOXl4 84 Toxic units (TVs) 6 acute toxicity units (TU,) 7 chronic toxicity units (TV,) 7 Toxicity acute toxicity 4 CCC for 85 chronic toxicity 4 CMC for 85 whole effluent toxicity 4, 71

143Toxicity persistence 23 Toxicity reduction evaluations 308 letters 118-l 19 additional testing 117-l 18 administrative orders 114 approach 114 circumstances warranting aTRE 117 consent decrees 114 evaluation criteria 115 guidance documents 114 requiring TREs 118 toxicity identification evaluation (TIE) 116 TREplans 115 Toxicity test endpoint concentrations 

### acutetoxicity endpoints (ATEs) 4 chronic toxicity endpoints (CTEs) 4 Toxicity testing 11 composite sample 13 flow-through toxicity test 13 grab sample 13 off-site tests 11 on-site tests 11 static toxicity test 1 3 Toxicity testing procedures 58 Treatment plant performance 97 Triggers for permit limit development 58, 63-64 Tualatin River Basin 68

UDKHDEN 77 ULINE 77 UMERCE 77 UOUTPLM 77 UPLUME 76, 77
Variability effluent variability 16 exposure variability 16 species sensitivity differences 16 Violation review 124 WASP4 84 Wasteload 67 Wasteload allocation schemes 67, 69 Wasteload allocation (WL4) 1 Water quality criteria 1, 29, 32 aquatic life 34 criterion continuous concentration (CCC) 32 criterion maximum concentration (CMC) 34, 35 RACsfor non-carcinogens 39 reference ambient concentration (RAC) 36 reference tissue concentration (RTCs) 37 Water quality models continuous simulation 81, 98 dynamic 98 lognormal probabilistic 82 Monte Carlo 81, 98 single value steady state 97 two value steady state 98 Water quality standards 1 biological criteria 1 narrative water quafity criterion 1 numeric criteria 1 water quality criteria 1 Water quality standards regulatory considerations 30 Section 303(c)(2)(8) of CWA 30 40 CFR 122.44 & 40 CFRPart 131 31 Section 307(a) of CWA 30 Section 131.l 1 Standards Regulation 2.1 29 When isachemical-specific limit sufficient? 62 Whole effluent approach 4 Whole effluent toxicity “pass/fail” tests 104 acute endpoint sensitivity 112 chronic endpoint sensitivity 112 description of limits 112 detection levels 112 end-of-pipe approach 104 test methods 112
use of acute versus chronic tests 112 Whole effluent toxicity data generation 58 WfA 67

*Thisis not a comprehensive index. Only topics of importance 

### arehighlighted.

144

### APPENDICES A. RawData
B. EPA Regulations andPolicies
C. AmbientToxicityTestingandDataAnalysis
D. DurationandFrequency
E. LognormalDistributionandPermitLimitDerivations
F. Sampling

c. TheDevelopment ofABiologicalIndicatorApproachtoWaterQuality-based HumanHealthToxicsControl
H. Reference Dose(RFD):Description andUse inHealthRisk Assessment
I. Chemicals Available onIRIS

145

# APPENDIX 

# A-1 TOXICITY TEST PRECISION DATA

# MARINE/ESTUARINE SHORT-TERM CHRONIC TOXICITY TESTS

## SHEEhiEAD MINNOW (Cyprinodon variegatus) Seven-day Larval Survival and Growth Test Single Laboratory Precision Data
Table A-l-l. Single laboratory precision of test performed in 40 fathoms artificial seawater, using larvae from fish maintained and spawned in 40 fathoms artificial seawater, using copper asthe reference toxicant [l].

Test Number ; 

### , Most 1 Go 1

1 0.05 0.1133 2 I <0.05* I 0.0543 3 <0.05’ 0.0418 4 I 0.05 0.0632 

## 5 i <“‘05’ 0.0577 6 I 0.05 0.0483 7 0.05 0.0796 8 j 0.05 j 0.1235 n: 5 Mean: I 0.05 CV(o/o): NA 1 i.0727 41.82 

## (m$l) 0.1523 0.0975 0.0714 0.0908 0.0998 0.1325 0.1597 0.2364 Sensitive Endpoint S
c G S
s c G G

40.77 i I
* The lowest concentration tested was 0.05 mg./l NOEC Range: ~0.05’ - 0.05 mg/l. Copper concentrations in Tests l-6 were 0.050, 0.10, 0.20, 0.40, and 0.80 mgil and Tests 7-8 were 0.025, 0.050, 0.10, 0.20, and 0.40 mgll. Prepared by Florence Kessler, TAI, Cincinnati, OH, fanuary 11, 1990 (ICp Program, versron 1.l b).
Table A-l-2. Single laboratory precision of test performed in 40 fathoms artificial seawater, using larvae from fish maintained and spawned in 40 fathoms artificial seawater, using sodium dodecyl sulfate (SDS) asthe reference toxicant 

## PI.

2 ,l.O 3 1.0 ( 2.3051 1 2.8367 ’ S 4 0.5 1.9855 2.6237 ; G 5 1.0 1.1901 ; 1.4267 5 6 0.5 ---- , 1 1.1041 1.4264 1 c fl: 6 ! 6 I 6 I Mean: , 0.8 1.5456 1.9595 ’ CVl%): NA 31.44 I 31.82 !

NOEC Range: 0.5 - 1.Omg!l (this represents a difference of one exposure concentration). SDS concentrations in Tests l-2 were 1.O, 1.9, 3.9, 7.7, and 15.5 mg/l and in Tests 3-6 were 0.20, 0.50, 1.0, 1.9, and 3.9 mgif. Prepared by Florence Kessler, TAI, Cincinnati, OH, January 11, 1990 (ICp Program, version 1.l b). Table A-l-3. Single laboratory precision of test performed in natural seawater, using larvae from fish maintained and spawned in natural seawater, using copper asthe reference toxicant [ 11.
I Most Test ’ Sensitive Number 1 Endpoint 1 ; 125 1 320.3 j 437.5 j S -

4 125 5 ’ 125
n: T 5 Mean: I 106.2 182.3 I 323.0 ’ C 333.4 , 483.4 I 5 228.4 343.8 ’ S

300.4 I 396.9 , 1 CW%k 1 NA I 33.0 : 19.2 ’ I

* No linear interpolation estimate could be calculated from the data, since none

of the group response means were lessthan 50 percent of the control response mean. NOEC Range: 31 - 125 mg/l (this represents a difference of two exposure concentrations). Prepared by Elise Torello, SAIC, Narragansett, RI, and Margarete Heber, EPA, Washington, DC, February 1990 (ICp Program, version 1.l b).

Table A-l-4. Single laboratory precision of test performed in natural seawater, using larvae from fish maintained and spawned in natural seawater, using sodium dodecyl sulfate (SDS) asthe reference toxicant [l].

’ NOEC Test I Number 1 (mg/l) I 1 ’ 2.5 2 1.3 3 I / 1.3 4 1.3 5 , 1.3
n: 5 Mean: 1.5 CW%l: ; NA 

# 2s ; (:9/u
2.9 NC’

1.9

I 2.4 1.5 i
I 4 2.2

! 27.6 

# tSI, j

3.6 NC2
I 2.4 NC2 

# -I 1.8

----.- - 3 

# I 2.6 35.3 

### ’ Most

, Sensitive I Endpoint f------

I s I G 5 I c 5 i---- ---

NOEC Range: 1.3 - 2.5 mg/l (this represents a difference of one exposure concentration).
‘No Linear interpolation estimate could be calculated from the data, smce none of the group response means were lessthan 75 percent of the control response

-. 2No linear interpolation estrmate could be calculated from the data, smce none of the group response means were lessthan 50 percent of the control response mean. Prepared by Elise Torelfo, SAIC, Narragansett RI, and Margarete Heber, EPA, and Washington, DC, February 1990 (ICp Program, version 1.I b).

A-l-l

## SHEEPSHEAD MINNOW (Cyprinodon variegatus) Seven-day Larval Survival and Growth Test Interlaboratory Precision Data
Table A-1-5. Interlaboratory precision of test using an industrial effluent as the reference toxicant [ 11.

Most Sensitive Endpoint Test 1 NOEC ;i$ GO Number A- -!%,--,----- -‘--P?-- .~_____-~-~ .~_-. .- - - -

Laboratory A I 1 , 3.2 (S,G) / 7.4 (5) I 7.4 (G) 2 1 3.2 (S,G) 7.6 (S) 14.3 (G) Laboratory B 1 3.2 (S,G) 5.7 (C} 9.7 (C) 2 3.2 (S,C) 5.7 (C) 8.8 (C) Laboratory C I 1 1 .o (5) 4.7 (5) 7.2 (5) Laboratory II 1 ’ 3.2 (S,G) 7.4 (G) 24.7 (G) 2 ’ 1.0(G) -----.-F.-..e---1 ----- 5.2 (5) 7.2 (5) tl: 7 7 7 Mean: j 2.6 5.5 11.3 CV(%): NA 44.2 56.9
NOEC Range: 1.O- 3.2 percent (this represents a difference of one exposure concentration). Prepared by Elise Torelto, SAIC, Narragansett, RI, and Margarete Heber, EPA, and Washington, DC, February (Itp Program, version 1.l b).


## SHEEPSHEAD MINNOW (Cyprinudm variagatus) Embryo-larval Survival and Teratogenicity Test Single Laboratory Precision Data
Table A-l-6. Single laboratory precision of test performed in HW Marinemix artificial seawater, using embryos from fish maintained and spawned in HW Marinemix artificial seawater, using copper as the reference toxicant [l].

Test Number I ECIO 60 7 NOEC bJg/u OJgm wi/J) 1 173 189 198 234 240 2 l * t * 240 3 l l t t I 240 ’ 4 182 197 206 240 , 240 5 171 187 197 234 240 6

. * l * / <200

l l l c 220 195 203 : 208 I 226 , 220
n: 4 4 4 4 7 Mean: 180 194 202 233 234 CV(%): 6.1 3.8 2.8 2.5 NA

l Data do not fit the Probit model. NOEC Range: 200 - 240 (this represents a difference of two exposure concentrations).

A-l -2

## SHEEPSHEAD MINNOW (Cyprinodun variegatus) 

## (continued) Embryo-larval Survival and Teratogenicity Test Single Laboratory Precision Data
Table A-l-7. Single laboratory precision of test performed in HW Marinemix artificial seawater, using embryos from fish maintained and spawned in HW Marinemix artificial seawater, using sodium dodecyl sulfate (SDS) as the reference toxicant [l],

Mean: 1.3 11.7 ’ NA

l Data do not fit the Probit model. NOEC Range: 2.0 - 4.0 ug/l (this represents a difference of one exposure concentration)



## INLAND SILVERSIDE (Menldia beryllfna Seven-day Larval Survival and Growth Test Single Laboratory Precision Data
Table A-l-8. Single laboratory precision of the inland silverside (Menidio beryllina) larval survival and growth test performed in natural seawater, using larvae from fish maintained and spawned in natural seawater, using copper as the reference toxicant [I].

Test ; Number 1 2 ’ 3 4 5 NOEC (WU -----63 125 63 125 31
n: 5 Mean: 81.4 CV(%j: ’ NA 

# I / (ItgL;1)
1 96.2 207.2 j 2189 ! - 177.5 1 350.1

I 43.7 

## I I (i$i) A-----148.6 NC 493.4 ! 241.4

+Y1 340.8 I 50.7 

# I Most 1 Sensitive 1 Endpoint 

# I s I i ! s t”-

l No linear interpolation estimate could be calculated lrom the data, since none

of the group response means were less than 50 percent of the control response mea”. NOEC Range: 31 - 125 ug/l (this represents a difference of two exposure concentrations). Prepared by Elise Torello. SAIC, Narragansett, RI, and Margarete Heber, EPA, and Washington, DC, February 1990 (ICp Program, version 1.lb). Table A-l-9. Single laboratory precision of the inland silverside (Menidia beryllina) larval survival and growth test performed in natural seawater, using larvae from fish maintained and spawned in natural seawater, using sodium dodecyl sulfate (SDS) asthe reference toxicant [l].
I I Test 1 NOEC ( ICL, i I& Most 1 Sensitive Number ; 

### (mg/l) ) @q/l) (mg/l) Endpoint

NOEC Range: 1.3 mg/l Prepared by Eke Torello, SAIC, Narragansett, RI, and Margarete Heber, EPA, and Washington, DC, February 1990 (ICp Program, version 1.1b).

A-l-3

### Seven-day Survival, Growth, and Fedundlty Test Single Laboratory Precision Data
Table A-1-10. Single laboratory precision of the mysid (Mysidopsis bahia) survival, growth and fecundity test performed in natural seawater, using juveniles from mysids cultured and maintained in natural seawater, using copper asthe reference toxicant [I].

5 i125 I 157.7 j 200.3 1 S I n: 

# 5 Mean: 

# i 112.6 CV(%): / NA

l No linear interpolation estimate could be calculated from the data, since none of the group response means were less than 50 percent of the control response mean, NOEC Range: 63 125 ugll (this represents a difference of two exposure concentrations). Prepared by Eke Torello, SAIC, Narragansett, RI, and Margarete Heber, EPA, and Washington, DC, February 1990 (ICp Program, version 1.lb).

Table A-l-11. Single laboratory precision of the mysid (Mysidopsis bohia) survival, growth, and fecundity test performed in natural seawater, using juveniles from mysids cultured and maintained in natural seawater, using sodium dodecyl sulfate (SDS) as the reference toxicant [l).

__---

‘No linear interpolation estimate could be calculated from the data, since none of the group response means were lessthan 75 percent of the control response mean.
‘No linear interpolation estimate could be calculated from the data, since none of the group response means were lessthan SOpercent of the control response mean. NOEC Range: ~0.3

_5.0 mg/l (this represents a difference of four exposure concentrations). Prepared by EliseTorello, SAIC, Narragansett, RI, and Margarete Heber, EPA, and Washington, DC, February 1990 (ICp Program, version 1.l b).

A-l-4

## SEAURCHIN (Arhcia punctrrlata) Fertilization Test Single Laboratory Precision Data Table A-1-12. Single laboratory precision of the sea urchin Table A-1-14. Single laboratory precision of the sea urchin (Arbucio punctuloto) fertilization test performed in natural (Arbacia punctulata) fertilization test performed in natural seawater, using gametes from sea urchins maintained and seawater, using gametes from sea urchins maintained and spawned in artificial seawater (40 Fathoms), using copper spawned in natural seawater, using copper asthe reference asthe reference toxicant [l]. toxicant [l].

Test ! NOEC

CV(%): ( NA 

# T c
! 1 (!iil)



### 8.92 26.35 11.30 34.28 36.67

5 23.51 54.60
UOEC Range: ~5.0 - 12.5 ug/l (this represents a difference of one exposure NOEC Range: ~6.1

_24.4 ug/l (this represents a difference of two exposure roncentration). concentrations). kpper concentrations in Test 1 were 2.5, 5.0, 10.0, 20.0, and 40.0 ug/l and in rests 2-S were 6.25, 12.5, 25.0, 50.0, and 100.0 ug/l. Prepared by Florence Kessler, TAI, Cincinnati, OH, lanuary 11, 1990 (ICp Program, version 1.l b). Prepared by Elise Torello, SAIC, Narragansett, RI, and Margarete Heber, EPA, and Washington, DC, February 1990 (ICp Program, version 1.l b).

Table A-1-13. Single laboratory precision of the sea urchin Table A-l-15. Single laboratory precision of the sea urchin (Arbacio punctulota) fertilization test performed in natural (Arbocio punctulato) fertilization test performed in natural seawater, using gametes from sea urchins maintained and seawater, using gametes from sea urchins maintained and spawned in artificial seawater (40 Fathoms), using sodium spawned in natural seawater, using sodium dodecyl sulfate dodecyl sulfate (SDS) as the reference toxicant [l]. (SDS) asthe reference toxicant [l].

Test Number
--- 1 2 3 4 5
n: 4 5 5 Mean: 1.4 1.73 2.38 CV(%): NA 1 29.7 23.3
NOEC Range: 1.2 - 3.3 mg/l (this represents a difference of one exposure concentration). SDS concentrations for all tests were 0.9, 1.8, 3.6, 7.2, and 14.4 mg/l. Prepared by Florence Kessler, TAI, Cincinnati, OH, January 11, 1990 (ICp Program, version 1,l b). NOEC Range: 0.9 - 1.8 n-g/l (this represents a difference of one exposure concentration). Prepared by Elise Torello, WC, Narragansett, RI, and Margarete Heber, EPA, and Washington, DC, February 1990 (ICp Program, version 1.l b). Test Number
- 1 2 3 4 5
n: Mean: 

### cv(%): 

# : I NOEC b%lm 12.2 12.2 24.4 ~6.1

6.1 4 13.7 NA 30.3 46.3 26.2 34.1 11.2 17.2

-,- 5 5 22.8 29.9 41.9 48.2

A-l -5

## REDMACROALGAE(C~~~~~~ga~~~~ Reproduction Test Single Laboratory Precision Data
Table A-l-16. Single laboratory precision of the red macroalga (Champio porvu/u) reproduction test performed in SO/SO natural seawater and GP-2 artificial seawater. Copper is the reference toxicant [l].

Test NOEC ] lCLs Number , WI/u WIiiu 1 I 1.0 1.67



### c -

NOEC Range: 0.5 - 1.Oug/l (this represents a difference of one exposure concentration). Prepared by Elise Torello, SAIC, Narragansett, RI, and Margarete Heber, EPA, and Washington, DC, February 1990 (ICp Program, version 1.1b). Table A-1-17. Single laboratory precision of the red macroalga (Chompio porvulu) reproduction test performed in 50/50 natural seawater 

### and GP-2 artificial seawater. Sodium dodecyl sulfate (SDS) is the reference toxicant [l] (personal communication with G. Thursby, SAIC, Narragansett, RI).

Test Number 1 2 3 4 5 6 7 8 9
n: Mean: CV(%): NOEC

+

co.48 0.4 co.48 0.2

0.26 ; 0.2 0.09 I 0.1 0.16 0.2 0.09 i 0.1 <0.29 I 0.3

5 9 0.22 I 0.31 NA I 69.0 

# 1

0.3 0.6 0.2 0.4 0.5 0.3 0.3 0.2 0.4 9 0.36 37.0
NOEC Range: 0.09 - 0.48 mg/l (this represents a difference of two exposure concentrations). Prepared by Elise Torelfo, SAIC, Narragansett, RI, and Margarete Heber, EPA, and Washington, DC, February 1990 (IQ Program, version 1.1b).

Table A-1-18. Single laboratory precision testing of the red macroal a (Chompia porvulo) reproduction test in natural seawater (30 OJOOsalinity). The reference toxicants used were copper sulfate (Cu)Pg2and sodium dodecyl suffate (SDS)2t3 [7].



## cu@g/l) SDS

## (mg/l)
__---- Test 

# r -NOEC 1 Gs I ‘CSO NOEC GS GO

CV(%): 1 NA 1 61.09 ’ 34.45 1 NA 1 62.29 1 22.92
‘Copper concentrations were OS, 1.O,2.5, 5.0, 7.5, and 10 ugll. Concentrations of Cu were made from a 100 ug/ml CuSO4 standard obtained from Inorganic Ventures, Inc., Brick, NJ.
2All tests were conducted at 23 + l°C in natural seawater with irradiance set at 40 uE/m’,‘s.

%DS concentrations were 0.0375, 0.075, 0.15, 0.30, 0.60, and 1.20 mg/l. Concentrations of SDSwere made from a44.64 + 3.33 mg/ml standard obtained from U.S. EPAEMSL, Crncinnati, OH. Prepared by Steven H. Ward and Glen Thursby, EPA, Narragansett, RI(ICp Program, version 1.l b).

A-l -6

# FRESHWATERSHORT-TERMCHRONICTOXICITYTESTS

## FATHEAD MIWWDW (Pimephales promelas) Seven-day Larval Survival and Growth Test and Embryo-larval Survival and Teratogenicity Test Single Laboratory Precision Data
Table A-1-19. Single laboratory precision of the fathead minnow (Pimepholes promelos) embryo-larval survival and teratogenicity test performed in using Diquat as the reference toxicant [2].



## I Test I LCl I

2 2.31 3 1so 4 1.71 5 1.43 ~ n: 5 Mean: 1Sl CV(%): 41.3

Table A-1-20. Single laboratory precision of the fathead minnow (Pimephales promelos) embryo-larval survival and teratogenicity test performed in using cadmium chloride as the reference toxicant (21.

Test Number 1 --4 2 3 4 I 0.014 0.006 0.005 0.003 

### 5 -- -- 

### ~~..OEL n: 5 Mean: 0.0068 0.012 CV(%): 62 NA

NOEC Range: 0.011

_0.013 mg/l (this represents a difference of one exposure concentration).

A-l-7

## FATHEAD MINNOW (Pimephaks prume/as) Seven-day Larval Survival and Growth Test Single Laboratory Precision Data Table A-l-21. Single laboratory precision of the fathead minnow (Pimephales promelos) larval survival and growth test performed in using NAPCP asthe reference toxicant [2].

Test NOEC* Number (WI) 1 256 2 128 3 256 4 128 5 128
n: 5 Mean: cv(%): I 179.2 NA

*Raw data unavailable, It25 and Itso values could not be calculated.
NOEC Range: 128 _ 256 ug/l (this represents a difference of one exposure concentration).
Table A-l-22. Results of the performance evaluation for contract laboratories conducted for the California Regional Water Quality Control Board. All tests were conducted using potassium chromate (expressed as Cr+6) and testing the fathead minnow (Pimephales promelos) in the 7-day subchronic tests [3].

Lab


### - l ! Tap’ ! 2X 2 3 4 5 6 I 7 ’ 8 9 MHRW ! 3X 10 - - _. - --..- .-

Mean:
cv (%): I

’ Moderately hard tap water

2 Control with three replicates and all concentrations with two replicates.
3 Value is extrapolated and is not included in coefficient of variation calculation.

4 Weight measurements made with questionable techniques.
’ Dechlorinated Lake Ontario tap water.
6 Not reported.
’ Well water mixed with spring water, moderately hard.
’ Value may be skewed as middle concentration had 45 percent survival but no weights reported.

A-l-8

## Seven-daylarval Survival and GrowthTest Interlaboratory Precision Data
Table A-l-23. lnterlaboratorv orecision data of the fathead minnow 1Pimeohale.s oromelas) 7-dav larval survival and orowth test. Combined frequency distribution for survival NOECs for all participatkg kboratdries [2]. ’ ’ a

NOEC Frequency (%) Distribution
.- Tests with 2 Reps Tests with 4 Reps Sample Sodium Pentachlorophenate ’ l--.--.-L Median 1 +1(a) 35 53 Sodium Pentachlorophenate 2 42 Potassium Dichromate 1 47 Potassium Dichromate 2 41 Refinery Effluent 301 26 Refinery Effluent 401 37 Utility Waste 501 56 42 47 41 68 53 33

’ Percent of values with one concentration intervals of the median.
’ Percent of values within two or more concentrations intervals of the median. 11 56 33 11

Table A-l-24. Interlaboratory precision data of the fathead minnow (Pimephales promelos) 7-day larval survival and growth test. Combined frequency distribution for weight NOECs for all participating laboratories [2].

NOEC Frequency (46) Distribution 

# I ---~--~~-- Tests with 2 Reps rtTests with 4 Reps

- ~ r *I(a) .- >Z(b)

Median 

### -~. - *l(a) 

### >W)

41 

### 0 63 

### f 0 47 18 47 41 53 12 47 16 : 33 I 56 1 11 61 I 28 33 I 56 ’ 11 I 57 43 0 22 45 33

88 0 63 25 j :: 75 I 25 0 Sample Median

- __~ .~ .-~ Sodium Pentachlorophenate 1 59 Sodium Pentachlorophenate * 37 Potassium Dichromate 1 35 Potassium Dichromate 2 d--- 12 Refinery Effluent 301 I ;; Refinery Effluent 401 Utility Waste 501 11

’ Percent of values with one concentration intervals of the median.
’ Percent of values within two or more concentrations intervals of the median.

A-l -9

## CERIODAPHMA(Ceriodaphnia dubia] Seven-day Reproduction Test Single Laboratory Precision Data

Table A-1-25. Single laboratory precrsion of (Cerioduphnio dubio) reproduction test performed in using sodium pentachlorophenol as the reference toxicant [2].

Table A-1-26. Single laboratory precision, from six discrete laboratories, of the (Ceriodophnio dubia) reproduction test performed using sodium chloride (NaCI) as the reference toxicant. Tests were conducted in 1989 [4]. Test Number NOEC @W) lC25 IGO (w/U (mg/l) -- -~ .- -- 19 0.30 I 0.3754 0.4508 46A 0.20 0.0938 0.2608 460 0.20 0.2213 0.2897 I 49 0.20 0.2303 0.2912 55 0.20 0.2306 0.3177 56 0.10 0.1345 0.1744 57 0.20 0.2241 ' 0.2827

n: 7 7 7 Mean: 0.20 I 0.2157 0.2953 CV(%): , NA , 41.1 27.9
NOEC Range: 0.25 - 0.30 mgil (these values all fell within the same concentration range). Prepared by Florence Kessler, TAI, Cincinnati, OH, fanuary 11, 1990 (ICp Program, version 1.l b).

laboratory Test NOEC Number k!5

, (mg/l) 1 (mg/l) 1 (rug/l) ‘Go

A 0.77 1.34 1.32 4 l.ooR ’ 0.67 1.28

--F n: Mean:

4 ! 0.50~ 5 1.oOR

-.- -. 6-
n: -. t +!L / Mean: CV(%):

--c -T i y:“’
; 1.OOs o.50s i 3 4 I I.$

5 I 1.oos 1.31 1.12 6 1.04 24.11

1.23 0.46 1.25 1.13 1.22 0.69 0.88 0.81 ' 1.16 1.84 1.57 ..- - -

! 6

1 1.43 24.37 -. -

1.49 1.02 1.50 1.44 1.49 6 1.oos 1.21 ! 1.51 - -. - - _-. _ - ._ -*- - -.-- n: Mean: ( ! i.83 Y.13 ! Y.41 CV(%) : NA 16.54 1 13.62
R= Reproduction was the most sensitrve endpoint. 5 = Survival was the most sensitive endpoint. Test NOEC Laboratory Number (w/l) IQ5 (w/l) D 1 0.50R 2 0.2SR 3 1.oos 4 1.oOs 5 1.00s 0.58 0.30 0.84 1.04 1.04 

# I 4 --6 -L -OSOR -r-L. 0 76

n: 6 Mean: 0.71 1 60.76

-. - "'A 37.55 1 1.oosq 0.44

4 ' 1.00~ 5 1.oos

# I
- 1.04 1.06 1.13 1.13 1.19 -- 6 1.00 27.96

0.61 0.63 0.66 0.65 IC50 (mg/O

0.84 0.60 1.22 1.38 1.37 1.14 --. 6 1.08 28.56

0.74 1.37 1.37 1.42 1.42 1.46 -- 6 1.30 21 20 -L 1.13 1.20 0.83 0.81

Prepared by William Peltier, EPA, Region IV, November 28, 1990 (ICp Program, version 1,l b).

A-1-10

## CERlODAPHulA(Curiodaplinia dubid Seven-day Larval Reproduction Test Interlaboratory Precision Data
Table A-l-27. Interlaboratory precision of (Cerioduphnio dubia) reproduction test, using sodium chloride (NaCI) as the reference toxicant. The single lab precision data are presented in the preceding table [4]. -

Laboratory A B C



### ~ D E F
n: Mean: a/(%): NOEC ml/l) 0.83 0.83 0.83 0.71 1.00 0.50 6 0.80 NA 0.89 1.26 1.04 1.43 1.13 1.41 0.76 1.09 1 .oo 1.30 0.63 0.95 - 6 I 6 0.91 ! 1.24 20.53 15.17 Prepared by William Peltier, EPA, Region IV, November 28, 1990 (ICp Program, version 1.l b). Table A-l-28 Interlaboratory precision of (Ceriodo reproduction test, using an industrial effluent as tf:hnia dub) e reference toxicant and sodium chloride (NaCI) as a reference toxicant. Tests were conducted in May 1987 [ 31.

Effluent Reference Toxlcant Lab Go w lC25w ICm (%,I ii, (96)

-- - A 6.20 4.9 33.0 il.8 B 8.40 6.2 38.8 30.8 D 7.69 5.8 36.3 29.4 E 6.34 5.0 36.6 28.0 F 4.00 1.2 8.1* 1.21* I 2.84 1.9 35.1 25.2 K 6.89 5.3 18.4 13.2 M 5.70 1.9 38.1 31 .o N 7.43 5.9 27.8 10.4 0 0.04’ 0.02* 35.1 27.3 -^.-. t-l: 9 9 Mean: ’ z.17 I.4 32.8 24.1 CV(%): 29 67 21 31

‘Values were excluded from mean calculations because they fell outside of + 2 standard deviations. For this reason, these values are considered statistical outliers and, according to EPA’s toxicity methods guidance [2] on reference toxicant control charts, are excluded.

Table A-l-29. Results of the performance evaluation for contract laboratories conducted for the California Regional Water Quality Control Board. All tests were conducted using sodium chloride and testing Cerioduphnio dobiu in the 7-day chronic tests 131.
I / X Young/ h5 KU NOEC Lab Water ’ Age Control ’ 

### (g/l NaCI) Endpt

1 ’ Tap1 YCT/Algae 0-4;<24 1 7.80.202 (0.14-0.35) -- co.25 R 2 Hard W3 TF/Algae O-4 26.51.3 (0.78-l .7) 1.0 R 3 DMW4 YCT/Algae O-6 24.90.21 2 (0.17-0.54) <0.25 R 4 Tap5 YCT o-4 17.20.49 (0.35-l .O) 0.5 R 5 HRW YCT 0-4;<24 19.80.42 (0.20-I .I) 0.5 R 6 Surface6 YCT/Algae O-6 14.80.90 (0.66-l .l) 0.25 R 7 MHRW YCT/Algae 4-8 17.20.56 (0.24-0.64) 0.25 R 8 MHRW YCT ~24 16.80.21 2 (0.11-o. 32) 0.25 R 9 MHRW YCT O-4 12.80.71 (0.56-0.81) 0.50 R 10 DMw4 YAT/Algae o-4 4 31so.91 (0.45-l .l ) 1.0 R Mean: O.-j6 CV(%): j 40

’ Moderately hard tap water. MHRW = Moderately hard reconstituted water ’ Dose response curve limited. HRW = Hard reconstituted water 3 Hard well water. WV = Well water 4 Ten percent diluted mineral water. YCT = Yeast-Cerophyl-Trout chow 5 Dechlorinated Cake Ontario tap water. YAT = Yeast-Alfalfa-Trout chow 6 Briones reservoir water. TF = Trout food suspension R = Reproductive endpoint Algae = S&nostrum capricornotum

A-l -11

## CERIODAPHRIA (Cerhdapnnia dubiaj 

## (contlnued) Seven-day 

### Larval Reproduction 

### Test Interlaboratory Precision Data

Table A-1-30. Interlaboratory precision data for Ceriodophniu dubiu summarized for eight materials, including reference toxicants and effluents [S].

Test Mean Material ’ I& 1.34 Sodium chloride Industrial Sodium chloride Pulp & Paper Potassium dichromate Pulp & Paper Potassium dichromate Industrial Mean cv 46 GS cv % / 29.9 1 1.00 34.3 3.4 : 83.3 

# I I I 3.2 78.1 0.96 57.4 0.90 44.4 60.0 28.3 47.3 27.0 35.8 23.4 32.7 70.2 55.7 f2.2 53.2 29.3 46.8 69.8 67.3 36.7 ~-. 

# I8 I8

37.5 39.0 1Standard Deviation: 1 23.0 19.1



## SELEHASTRUM CAPRICORUUTUM Growth Test Single Laboratory Precision Data
Table A-1-31. Single laboratory precision of (Selenastrum cupricorrrufum) growth test performed in using cadmium as the reference toxicant [2].

Test I Number 1 1 2.3 2 2.4 3 2.3 4 2.8 5 2.6 6 2.1 7 2.1 8 2.1

1 ii;: ; 

### iI;7 8.42 44.1
‘Outlier values are excltided from mean because they fell outside of a QA control table for these reference toxicants. Control Variation (%Cv) 4.8 9.6 5.5 13.3 4.4 8.2 14.4

7.1 11.9 5.0 36.4’ 77.8’

Note: Sodium chloride concentrations were 1, 2, 4, 8, and 16 g/l in all tests. Prepared by Dr. Cornelius Weber, EPA, Cincinatti, OH, March 15, 1991.

A-1-12

# APPENDIX 

# A-2
EFFLUENT VARIABILITY DATA

### TableA-2-1. Percentmortality in 100percentcollected 1989 by grab method (personal communication W. Pettier, EPA, Athens, GA). Resultsindicate variability over 24 hours and differences in species sensitivity over time. Tests were

1830 0030 0630 1230 1830 0030

7/26/89 0630 0 1830 0
0030 0 1230 0 Date 

### 3/07/89 3/07/89 3/08/89 3/08/89 3/20/89 3/20/89 3/21/89 3/21/89 6/19/89 6/19/89 6/20/89 D.pulex 15 85 65 30 0 100

95 70

5 40 100 100

0 100 100

55 Time P.promelas 1230 0 conductedaccordingto methodsdescribedin Reference 6.
% Mortality in 100%Effluent C.dubia 100 100 100

80 100 100 100 100 100 100 100 100 100 100 100 100 0 0 0 0 0 0 6/20/89 0630 0 7125189 1230 0 7/25/89 1830 0 7126189 0030 0

Table A-2-2. LC50s for a POTW effluentover 17months. All testswereconductedusingCeriodaphniadubioandtestswere run for 48 hours. All testswereconducted accordingto the methodsdescribedin Reference 6. Dateswith romannumeral notation meanthat morethan one samplewascollected at different times over a short interval (1 to 2 days). (Data source: [8].) SampleDate 48hours LC50 (%) 08/23/86-I 71 03/09/87-I 71 05/02/87-I 35 05/03/87-I 65 05/04/87-I 71 05/23/87-I 71 05/23/87-II 71 05/23/87-III 61 06/27/87-I 36 06/27/87-II 41 06/27/87-III 18 09/22/87-I 71 12/18/87-I 87 01/05/88-I 68 01/05/88-II 63 Mean LC50: 60.0 cv (%): 31.1 n: 15 Table A-2-3. LC50s for a POTWeffluentover 7 months. All testswereconductedusingCeriodaphniadubiaandtestswere run for 48 hours. Alltestswereconducted according to the methodsdescribedin Reference 6. Dateswith romannumeral notation meanthat morethan one samplewascollected at different times over a short interval (1 to 2 days). (Data source: [8].) SampleDate

10/06/87-I 10/06/87-II 10/06/87-III 10/30/87-I 12/03/87-I 12/03/87-II 01/12/88-I 01/13/88-I 02/03/88-IX 02/03/88-X 03/03/88-III 03/03/88-IV 03/23/88-I 03/23/88-II 04/28/88-I 04/28/88-II 05/17/88-I 05/17/88-II MeanLC50: cv (%): n: 48hours LC50 (%) 71 71 71 87 61 35 61 58 50 50 87 81 25 35 50 55 61 35 58.0 31.4 18

A-2-1Table A-2-4. LCsOs for a POlW effluent over 12 months. Tests were conducted using either Ceriodaphnia dubia or fathead minnows or both. Ceriodaphnia tests were conducted for 48 hours while fathead minnow tests were 96 hours. Both the 4%hour and 96-hour fathead minnow results are shown in order to evaluate how the LCses for the two species compare. All tests were conducted according to the methods described in Reference 6. Dates with roman numeral notation mean that more than one sample was collected at different times over a short interval (1 to 2 days). (Data source: [8].) Table A-2-5. LCsOs for a POTS effluent over 4 months. Tests were conducted using either Ceriodaphnia dubia or fathead minnows or both. Ceriodophnio tests were conducted for 48 hours while fathead minnow tests were 96 hours. Both the 48-hour and g&hour fathead minnow results are shown in order to evaluate how the LCsOs for the two species compare. All tests were conducted according to the methods described in Reference 6. Dates with roman numeral notation mean that more than one sample was collected at different times over a short interval (1 to 2 days). (Data source: (El].) 

# i

_______LCEFL-------- Sample Date ! C. dubia P. promelas 48 hours ’ 48 hours 96 hours - -.- --- , 1 03/16/88-1 , 62 +--s---i--T---

06/09/88-l 18 * ’ -* 09/08/88-l I 68 >lOO ; >lOO 10/04/88-l ’ 61 -* l -1 I 10/04/88-II 63 12/l 4/88-l , 70 / 58 1 34 12/l 4/88-II 17 I 60 41 02/17/89-l ) 35 I 61 39 I 02/l 7/89-II 1 35 I 61 I 37 03/22/89-l 35 81 64 03/22/89-II ! 47 I 61 I 40 Mean LCs0: 46 I 59.6 ’ 40.0 CV (%): ! 42 22.4 I 29.7
n: I 11 ; 7 I 7

l Data not available. Note: Greater than (>) values were excluded from the mean LCc,o calculation. 

# c &cl (W __-__-__ Sample Date, C. dubicl , P. promelos &#fy; I !!;oclz;7z.

1l/l 5/88-f ’ 92’ / 67 1 37 11/16/88-l 61 >lOO I 100 1l/30/88-11 >lOO >lOO I 33 11/30/88-Ill 95 >lOO , >lOO 12/08/88-l 100 I 87 54 12/08/8&ll , >lOO ’ 87 / 53 12/13/88-l j 90 >I00 I 77 12/l 3/88-II 87 , 85 51 01/10/89-l 75 58 ; -* 01/10/89-h 61 ’ 41 l

-- I 01/19/89-l I 100 88 I 68 01/19/89-II I 87 84 69 01/25/89-l >lOO 01/25/89-II 1 95 87 I 64 85 I 56 01/31/89-l , 90 70 I 60 01/31/89-II I 63 70 I 60 ---- ----- ---------- -Mean: _---- 78.4 75.8 - - 61.3
cv (%): 33.1 19.6 I 27.7 It 14 12 14

*Not obtained.
Note: Greater than (>) values were not included in the mean LCso calculation.

A-2-2Table A-2-6. NOECs for a POlW effluent conducted 20 times over 1 year. All tests were conducted using Chompia parvulo according to methods described in Reference 1. All effluent samples were 24-hour composites collected post-chlorination. (personnal communication-Glen Thursby, SAIC, Narragansett, RI). Table A-2-7. NOECs for a POTW effluent over 1 year. All tests used Arbocia punctulata according to methods described in Reference 1. All effluent samples were 24-hour composites collected post-chlorination. (Data source: ERL-Narragansett, RI.)

% Effluent
-- -- -. .~-~

ICE I& i NOEC
.~. - ___ .- .- 12/09/85 12/l O/85 12/l l/85 12/l 2/85 0.41 12/l 3/85 3.09 12/l 5185 2.16 07/l 6186 2.99 07/l 7186 3.59 07/l B/86 .44 07/l 9186 .47 07/20/86 .24 07/21/86 .ll 07/22/l-36 9/09/86 09/l O/86 09/l l/86 09/l 2186 09114186 ! 1.76 .25 ! ~. .~. 1 0.65 1.23 

### 0.38 I 0.76 0.69 1.50 0.82 I 4.12 4.09 4.33 4.68 4.76 3.41 3.98 3.20 .84 5.19 .07 3.02 .l 7 4.13 .73 3.62 .57 1.89



### l-i: Mean: 

### I 18 18 18 2.2 3.1 I 4.2 1.25 1.25 2.50 1.25 5.00 5.00 5.00 5.00 5.00 5.00 7.50 5.00 5.00 2.50 7.50 7.50 1.25 2.50



### cv (46): / 52.8 / 46.8 1 NA

Table A-2-8. NOECs for a POlW effluent over 1 year. All tests used Mysidopsis bahia according to methods described in Reference 1. All effluent samples were 24-hour composites collected post-chlorination. (Data source: ERL-Narraqansett, RI.)

. 016Effluent

12/09 - 12/l 6/85

n: 4 ,4 R-Reproductive endpoint S-Suwval endpoint G-Growth endpoint Test Date --I 12fO9f 85 12/l Of85 12/l l/85 12/l 2185 12/l 3185 12/14/85 12/l 5185 07/l 6/86 07/l 7186 07/l 8186 07/l 9/86 07/20/86 07/21 I86 07/22/86 09/09/86 09/l l/86 09/l 2186 09/l 3f86 09f 14186 09/l 5/86 11/11/86 11 /13/86 1l/14/86 11/15/86 Mean:
cv (96):
n: , 24 , 24 11 

## I.- - --- -- bi 

# 4 1.09 1.41 0.75 3.28 2.65 1.11 1.29 0.17 0.21 0.63 1.09 0.54 0.40 0.40 0.31 0.47 0.21 3.30 0.23 0.10 0.27 0.88 0.82 0.34 0.91 101.3 % Effluent 

## kl 1.71 2.84 1.09 4.06 5.32 1.60 1.84 0.35 0.46 0.86 1.68 1.13 0.58 0.56 0.41 0.79 0.48 5.42 0.35 0.15 0.54 1.48 1.61 0.56 __- 1.49

96.9 

### .-. - NOEC 0.65 0.65 0.65 1.30 2.50 0.65 0.65 <0.30 <0.30 <0.30 <0.30 <0.30 <0.30 <0.30 <0.30 <0.60 <0.20

1.30 <0.20 <0.20

1.30 0.30 0.60 <0.30 I / 0.95 NA

Note: Lessthan (<) values wete excluded from CV and mean NOEC calculations.

A-2-3Table A-2-9. NOECs for a POTW effluent over 1 year. All tests used Menidiu beryllino according to methods described in Reference 1. All effluent samples were 24-hour composites collected post-chlorination. (Data source: ERL-Narragansett, RI.)

ll/ll - 11/18/86 ---

Mean:
cv (%):
n:
NC - Value is not calculable. NC 10.0 14.9 20.8 10.0 4.3 3.0 NA 3 3 4

Table A-2-10. LC5Os for a refinery effluent over 14 months. Tests were conducted using either Ceriodaphnio dubia or fathead minnows Pimepholes promelas or both. Ceriodophnia tests were conducted for 48 hours while fathead minnow tests were 96 hours. Both the 48-hour and 96hour fathead minnow results are shown in order to evaluate how the LC5Os for the two species compare. All tests were conducted according to the methods described in Reference 6. Dates with roman numeral notation mean that more than one sample was collected at different times over a short interval (1 to 2 days). (Data source: [8].)

01/05/88 02/09/88-l 02/09/88-l 03/02/88-l 03/02/88-II 03/24/88-l 05/06/88-l 07/l 4/88-l I <12 38 35 35 35 t
55 61 07/28/88-l , 37 I 35 22 

### - - --___

.- -.-

12/01/87 / 15 19 <12 cl2

l

l

t

l 25

07/28/88-II 09/29/88-l 12/01/88-l 12/07/88-l 01/27/89-l 01/27/89-/l 28 31 I 41 75 ’ 39 56 18 67 I ~25 25 34 13 100 61

71 60 03/23/89-l 1 58 ’ 54 20

--------+- Mean LCsO: 43 I 45 24 

### cv (%): 1 54 28 

### I 32
n: 16 15 10

l Data not available
Note: Lessthan values excluded from mean LCSO calculations Table A-2-11. LC5Os for a refinery effluent conducted over 6 months using fathead minnows (Pimephales promeias), Ceriodophnia dubio, and mysids (Mysidopsis bahio), according to methods described in Reference 6. (Data source: Dorn, 1989.)

4/l 7186 71.2 37.2 4123186 , 71.8 35.9 38 -.0 5/14/86 82.0 38.7 I 35.8 5/28/86 65.4 22.0 6/l l/86 82.0 I - 24.7 Mean NOLC: 66.3 32.9 ’ 32.8
cv (%): ! 18.7 19.5 21.6
n: 1 11 10 3

Table A-2-12. NOECs for a refinery effluent conducted over 6 months using fathead minnows (Pimepholes promelos), Ceriodaphnio dubia, and mysids (Mysidopsis bahia), according to methods described in References 1 and 2. (Data source: Dorn, 1989.)

3/ 19186 10.1 14.1 4/02/86 18.0 14.1 -

A-2-4Table A-2-13. LCsos for a manufacturing effluent conducted over 2 ears. All tests were conducted using Dophnio mo methods described in Reference 6. (Data source: [84no according to .)

Test Date (% Siient) 1982 (1st quarter) 56 1982 (4th quarter) 90 1982 (4th quarter) 70 1983 (3rd quarter) 69 1983 (3rd quarter) 36 1983 (3rd quarter) 36 1983 (3rd quarter) 32 1983 (3rd quarter) <ia 1983 (3rd quarter) 28 1983 (3rd quarter) 67 1983 (3rd quarter) <lO 1983 (4th quarter) 46 1983 (4th quarter) 75 1983 (4th quarter) 78 1983 (4th quarter) 24 1983 (4th quarter) 26 1983 (4th quarter) 32 1983 (4th quarter) 19 Mean LCso: 45.1 k24.3
cv (%): 53.9
n: la

Note: Lessthan (<) values were excluded from the mean LCso calculations. Table A-2-14. LCgy for a manufacturing effluent conducted over 8 All tests were conducted using Pimephales promelas according r?%thods described in Reference 6. (Data source: [8].)

Test Date 1979 (1st quarter) 72.0 1979 (1st quarter) 62.0 1979 (1st quarter) 52.0 1979 (3rd quarter) 39.0 1981 (2nd quarter) 64.0 1981 (4th quarter) 70.0 1982 (2nd quarter) 44.0 1982 (2nd quarter) 66.0 I985 (1st quarter) 59.6 I985 (4th quarter) >lOO.O I986 (2nd quarter) I 49.2 I986 (2nd quarter) 63.8 I986 (2nd quarter) 50.0 I986 (3rd quarter) 75.7 I986 (3rd quarter) 80.0 I986 (3rd quarter) 79.0 1986 (4th quarter) 71 .o Wean LCso: 64.5 + 15.1
zv (%): 23.5 1: 17

Note: Greater than (>) values were excluded from the mean LCso calculations. Table A-2-15. LC5Os for a manufacturing effluent conducted over 5 years. All tests were conducted using Pimephales promelos according to methods described in Reference 6. (Data source: [a].)

I Test Date (% Zent) 1980 (1st quarter) 18.0 1980 (2nd quarter) 11 .o 1980 (3rd quarter) 32.0 1980 (4th quarter) 16.0 1981 (1st quarter) 32.0 1981 (2nd quarter) 1981 (3rd quarter) 1981 (4th quarter) 1982 (1st quarter) 1982 (2nd quarter) 1982 (3rd quarter) 1982 (4th quarter) 1983 (1st quarter) 1983 (2nd quarter) 1983 (3rd quarter) 23.0 17.0 46.0

9.0 32.0 28.0 52.0 34.0 33.0 20.0

A-2-5 1983 (4th quarter) 43.0 1984 (1st quarter) 45.0 1984 (2nd quarter) 19.0 1984 (3rd quarter) 61.O

Table A-2-16. LC5os for a manufacturing effluent conducted over 5 years. All tests were conducted using Daphnio magna according to methods described in Reference 6. (Data source: 

### PI.)

Test Date I

--._B .~.. 981 (2nd quarter) 100.0 981 (3rd quarter) I >lOO.O 982 (3rd quarter) >lOO.O 984 (4th quarter) 80.0 985 (1st quarter) 75.0 1986 (1st quarter) 25.0 1986 (2nd quarter) 82.0 1987 (1st quarter) 75.0 1987 (1st quarter) I 24.0 1987 (1st quarter) ,100.o ,100.o

65.9 + 29.5 44.8
n: I 11

Note: Greater than (>) values were excluded from the mean LCc,o calculations.Table A-2-17. LC5Os for a manufacturing effluent conducted over 7 years. Ail tests were conducted using Uaphnio pulex according to methods described in Reference 6. (Data source: Table A-2-18. LC5Os for a manufacturing effluent conducted over 3 months. All tests were conducted using Daphnio mogno according to methods described in Reference 6. (Data source: [8].)

Test Date (% kkent) 1980 (izquarter) -- - -. .-- - ~ 55.0 1980 (4th quarter) 33.0 1981 (I st quarter) 60.0 1981 (1st quarter) 24.0 1981 (1st quarter) >lOO.O 1981 (2nd quarter) >lOO.O 1981 (3rd quarter) >lOO.O 1982 (3rd quarter) 1

1986 (3rd quarter) 1986 (3rd quarter) -1. 2100.0 >lOO.O >lOO.O - - .- - Mean LCse: 43.0 + 17.3
cv (%): 40.2
n: 10

Note: Greater than (>) values were excluded from the mean CC50 calculations. Test Date 

# I (96 EL) 982 (4th quarter) 982 (4th quarter) 982 (4th quarter) 982 (4th quarter) 982 (4th quarter) 982 (4th quarter) 982 (4th quarter) 982 (4th quarter) 982 (4th quarter) 982 (4th quarter) 982 (4th quarter) 1982 (4th quarter) Mean LCso:
cv (96):
n: I >lOO.O 81.O I 57.0 61.O 87.0 90.0 90.0 >lOO.O z-100.0 54.0 74.0 I >lOO.O 74.3 * 15.1 20.3 12

Note: Greater than (P) values were excluded from the mean LCso calculations.

A-2-6

# APPENDIX 

# A-3
ACUTE-TO-CHRONIC RATIO DATA

## TableA-3-1. ExampleofAcute-to-Chronic Ratios

Oil Refinery1

Mean ACR:
n: Range: Fathead Minnow

1.89 3.47 2.60 2.87 2.33 2.43 5.26 5.08 2.74 3.11 5.1 

### Ceriodaphnia 9.09 3.89 6.58 3.63 6.91 7.05 7.11 3.63 2.59 5.5 4.4

>10.0
> 7.1
> 3.3
> 2.0

> 3.0

2.8 5.42 

### 3.3 5.3 

### 11 13



### 1.89-5.26 2.59->10.0 Mysids 1.58 1.49 1.84

1.64 3 1.49-1.84

1Personal communication P. Darn.

2Personal communication M.L.C. Ramos and E. Bertoletti (Sao Paulo, Brazil).
Note: Greater than (>) values were excluded from mean calculations, 

## TableA-3-2. ExamplesofAcute-to-Chronic Ratios Chemical Manufacturers

Mean ACR:
n: Range: Fathead Minnow

0.17 0.07 8.4 7.6 >3.0

3.9 >3.0

1.8

3.7 6 0.07 - 8.4 

### Ceriodaphnia

> 1.0

> 1.0 >10.0 >50.0
> 2.9

> 1.4

1.4 1.4 3.9 2.8

> 2.0
> 4.0

4.0 1.4 5.5 1.8

> 3.3
> 3.3

> 3.3

1.4

> 2.0

5.5 1.5 1.4 5.0

>10.0
> 2.0
> 3.3

3.111 14.01

4.31 2.51 1.81 5.51 5.41 3.72 20 1.4->50

1Personal communication M.L.L.C. and E. Bertoletti (Sao Paula, Brazil).

2 Greater than (>) values were excluded from the mean calculation.

A-3-1

## TableA-3-3. ExampleofAcute-to-Chronic Ratios

POTWs

Fathead I Minnow 

### 1 Ceriodaphnia 1 ::; 5.5 14

I >

i 13.0 1.8 > 1.0 1.5 ! 1.0

2.6 1.8 I I 9.3 1.4

> 1.0 2.0
> 3.0 2.4 I 5.3 3.0 I 3.3 ; 3.0 5.4 5.5 I I > 3.0 4.9 I 3.0 I > 2.0

I > 8.0 2 I / > 1.0
> 3.3 I > 2.0 4.4 16.1
> 4.0
> 3.3 >lO.O I 2.6 I 5.7 2.8 I
I I >lO.O

> 2.0 I 1.4 I I 2.6
I > 3.3 I I 5.5 18

I 1.5 I I > 3.3 5.5 Mean ACR: ; 4.9 ----/- 3.8* il: / 11 21 Range: I 1.5 - 9.3 I 1.4 - 16.1

l Greater than (>) values were excluded from mean calculations.

A-3-2

## APPENDIX A REFERENCES

1.

2.

3.

4.

5.

6.

7.

8. Weber, Ct. et. al., eds. 1988. Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms. EPA 600/4-87/028. Office of Research and Development, Cincinnati, OH. Weber, C.I. et. al., eds. 1989. Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, 2d ed. EPA 600/4-89/001. Office of Research and Development, Cincinnati, OH. Norberg-King, T.j. Memorandum: Summary of Effluent Toxicity Data for the Technical Support Document for Water Quality-based Toxics Control, Chapters 2 and 3. April 11, 1989. U.S. EPA, Environmental Research Laboratory, Duluth, MN, to M.A. Heber, U.S. EPA, Enforcement Division, Washington, DC. Memorandum: Technical Support Document for Water Quality-based Toxics Control Data: Fathead Minnow Round Robin Data Analyzed to Obtain the IC25s. May 6, 1990. U.S. EPA, Environmental Research Laboratory, Duluth, MN, to M.A. Heber, U.S. EPA, Enforcement Division, Washington, DC, Peltier, W. January 23, 1991. Memorandum: Intra- and Interlaboratory Precision Data from Six Laboratories Conducting Short-Term Chronic Toxicity Tests Using Ceriodaphnia dubia. U.S. EPA, Region IV, Environmental Services Division, Athens, GA, to M.A. Heber, U.S. EPA, Enforcement Division, Washington, D.C. DeCraeve, GM., 1.0. Cooney, B.H. Marsh, T.L. Poltock, and N.G. Reichenbach. 1989. Intra- and Interlaboratory Study to Determine the Reproducibility of the Seven-day Ceriodaphnia dubia Survival and Reproduction Tests. Battelle, Columbus Division, Columbus, OH (in preparation). Peltier, W., and Cl. Weber. 1985. Methods for Measuring the Acute Toxicity of Effluents to Aquatic Organisms, 3d ed. EPA 600/4-85/013. Office of Research and Development, Cincinnati, OH. Ward, S.H. 1990. Technical Report: Procedures for Toxicant Testing and Culture of the Marine Macroalga, Champia parvula. U.S. EPA, Region II. Norberg-King, T.J. May 4, 1989. Memorandum: Additional Data for the Technical Support Document for Water Qualitybased Toxics Control, Chapters 2 and 3. U.S. EPA, Environmental Research Laboratory, Duluth, MN, to M.A. Heber, U.S. EPA, Enforcement Division, Washington, DC.

A-3-3

# APPENDIXB-1 SUMMARY OFCLEANWATERACT PROVISIONS

# CLEANWATERACT (33 U.S.C. 1251 SEQ.)

Statutory Authority for the Use of Toxicity Testing and Whole Effluent Toxicity Limitations in NPDES Permits:

Over the years, a developmental process has occurred regarding the use of biological techniques to assess effluent discharges and set permit limits. The acquisition of data and the development of new techniques has contributed to the refinement of toxicity testing methods, thus enabling EPA to more fully act in accordance with its mandates to implement statutory requirements relating to the attainment and maintenance of water quality.
Toxicity testing of Whole Effluents and Whole Effluent toxicity limitations in National Pollutant Discharge Elimination System (NPDES) permits are essential components in the control of the discharge of toxic pollutants to the nation’s waters. The use of toxicity testing and Whole Effluent toxicity limitation in the NPDES program is clearly authorized by the Clean Water Act (CWA).

Relevant provision of the CWA that provide the statutory authority for using toxicity testing and Whole Effluent toxicity limitations include the following:

•



### •

•

•

•

•

•

• Section 101(a) sets forth not only the goal of restoring and maintaining the “chemical, physical, and biological integrity of the Nation’s waters” (emphasis added), but also in Section 101(a)(3) the national policy of prohibiting the “discharge of toxic pollutants in toxic amounts” (emphasis added). As defined at Section 502(15), biological monitoring means that “determination of the effects on aquatic life, including accumulation of pollutants in tissue, in receiving waters due to the discharge of pollutants (A) by techniques and procedures, including sampling of organisms representative of appropriate levels of the food chain appropriate to the volume and the physical, chemical, and biological characteristics of the effluent, and (B) at appropriate frequencies and locations.” Section 304(a)(8) requires EPA to develop information on methods, including biological monitoring and assessment methods, to establish and measure water quality criteria for toxic pollutants on bases other than pollutant by pollutant criteria. Section 303(c)(2)(8) states, “Nothing in this section shall be construed to limit or delay the use of effluent limitations or other permit conditions based on or involving biological monitoring or assessment methods...” (emphasis added). Section 302(a) provides the authority to establish water quality-based effluent limitations on discharges that interfere with the attainment or maintenance of that water quality which shall assure protection of public health, public water supplies, and the protection and propagation of a balance population of shellfish, fish and wildlife, among other uses. The effluent limitations established must reasonably be expected to contribute to attainment or maintenance of such water quality. Under Section 301(b)(1)(C) and Section 402, all NPDES permits must comply with any more stringent limitations necessary to meet applicable water quality standards, whether numeric or narrative. CWA Section 308(a) and Section 402 provide authority to EPA or the Sate to require that NPDES permittees/applicants use biological monitoring methods and provide chemical, toxicity, and instream biological data when necessary for the establishment of effluent limits, the detection of violations, or the assurance of compliance with water quality standards. Section 510 provides the authority for states to adopt or enforce any standards or effluent limitations for the discharge of pollutants only on the condition that such limitations or standards are no less stringent than those in effect under the CWA.

B-1-1

# APPENDIXB-2 POLICIESFOR 

# TOXICSCONTROL

### 9016 Federal Register / Vol. 49, No. 48 / Friday, March 9, 1984/ Notices [OW-FRL-2533-1] DevelopmentofWaterQuality-Based PermitLimitationsforToxic Pollutants; NationalPolicy AGENCY: EnvironmentalProtection Agency(EPA). ACTION: Notice. SUMMARY: EPAhasissuedanational policystatement entitled“Policyforthe Development ofWaterQuality-Based PermitLimitationsforToxicPollutants.” Thispolicyaddresses thetechnical approachforassessing andcontrolling thedischargeoftoxicsubstances tothe Nation’swatersthroughtheNational PollutantDischargeEliminationSystem [NPDES) permitprogram. FOR FURTHER INFORMATION CONTACT: BruceNewtonorRickBrandes,Permits Division(EN-336). OfficeofWater Enforcement andPermits.U.S. EnvironmentalProtectionAgency, Washington.D.C.20460-7010.

B-2-1

### Federal Register / Vol. 49, 

### No. 48 

### / Friday, March 9, 

### 1984 1 Notices 9027


### ~UPPLENENTMY INFORMA~~OPK As the water pollution control effort in the United State8progressesand the “traditional” pollutants 

### (oxygen demanding and 

### eutrophying materials) becomesufficiently treated toprotect water quatity. attention isshifting towards pollutants that impact water quality through toxic effects.Compared with thetraditional pollutants, regulation oftoxic pollutants is considerably moredifficult. The difficulties include (I) thegreatnumber oftoxic chemicals that maypotentially bedischarged toreceiving waters and thedifficulties in their analysis: [z)the changesin thetoxic effectsof a chemical resulting from reactions with thematrix ofconstituents in which it exists; and [3)theinability topredict the effectsofexposure tocombinations of chemicals.

Toovercomesomeoftheseproblems. EPAand theStateshave begunto use 

### aquatic toxicity testsandvarious human health assessment 

### techniques to complement chemical analyses of effluents and receiving water samples. Because these 

### techniques ortheir application toeffluent testing arenew, EPA 

### andtheStateshave beencautious in their use.BasedonEPA’sevaluation ofthesetechniques and theexperiences ofseveral States,EPAisnow recommedingtheuseof biological techniques asacomplement to chemical-specific analyses toassess effluent dischargesandexpresspermit limitations. EPAhasissuedthese recommendations through astatement ofpolicy andisdeveloping atechnical guidance document tohelp implement Ihepolicy.

The complete testofthenational policy statement follows: Policy for the 

### Development of Water Quality-Based Permit Limitations for Toxic Pollutants Stoten?eni $poIic;,



### To confrr~i 

### pollutants beyond Best Available Technology Economically Achievable (BAT). secondary treatment. andotherCleanWater Act technology- basedrequirements in order to meet 

### water quality standard% 

### the Environmental Protection Agency (EPA) will use 

### anintegrated strategy consisting ofboth biological and chemical methodstoaddresstoxic and nonconventional pollutants from industrial and municipal sources.Where Statestandards contain numerical criteria for toxic pollutants, National Pollutent Discharge 

### Elimination System (NPDES) 

### permits will contain limits as 

### necessarytoassurecompliance with thesestandards. In addition 

### toenforcing specific numerical criteria, EPAand the Stateswill usebiological techniques and avaiiabte 

### dataonchemical effectsto assesstoxicity impacts and human health hazards basedonthegeneral standard of “no 

### toxic materials in toxic amounts.”

EPA, in its oversight role, will work 

### with Statestoensure that these 

### techniques areusedwherever appropriate. Under section 308and section 402oftheCleanWater Act (the Act), EPA 

### ortheStatemay require NPDESpermit applicants toprovide chemical, toxicity. and instream biological data necessarytoassure compliance with standards. Data requirements may be 

### determined ona case-by-casebasisin consultation with the State 

### andthedischarger.

Whereviolations ofwater quality standards areidentified orprojected, theStatewill beexpected todevelop water quality-based effluent limits for inclusion in any 

### issuedpermit. Where necessary,EPAwill develop theselimits in consultation with theState.Where there 

### isaeignificant likelihood oftoxic effectstobiota in thereceiving water, EPAandtheStates may 

### imposepermit limits oneffIuent toxicity and may require an NPDES permittee to conduct a 

### toxicity reduction evaluation. Where toxic effects arepresent but there isa significant likelihood that compliance with technology-based requirements will sufficiently mitigate theeffects, EPA 

### and the States 

### may require chemical and toxicity testing after installation of treatment and may reopenthepermit to incorporate additional limitations if neededto meetwater quality standards. (Toxicity data,which areconsidered “new information” in accordance 

### with 40CFR122.6z(a)(Z].could constitute causefor permit modification where necessary.)

To carry outthis policy, EPARegional Administrators will assurethat each Regionhasthecapability toconduct water quality assessmentsusing both biological andchemical methodsand provide technical assistance tothe States. Background



### TheCleanWater Act establivhes two principal basesfor effluent limitations. First, existing dischargers arerequired tomeettechnology-based effluent limitations that reflect the 

### bestcontrols available considering economic impacts. New source dischargers mustmeetthe bestdemonstrated technology-based controls. Second,where necessary, additional requirements areimposedto assureattainment and maintenance of water quality standards established by theState8and approved by EPA.In 0-2-2 establishing orreviewing NPDESpermit limits, EPAmustensurethat thelimits will result in theattainment ofwater quality standards andprotect designated water uses,including an adequate margin of 

### safety.

Fortoxic and nonconventional pollutants it maybedifficult in some situations todetermine attainment or nonattainment ofwater quality standards andsetappropriate limits becauseofcomplex chemical interactions which affect thefateand ultimate impact oftoxic substances in thereceiving water. In many cases, 

### all potentially toxic pollutants cannot be 

### identified by chemical methods. Insuch situations, it ismorefeasible toexamine thewhole effluent toxicity and instream impacts usingbiological methods rather 

### thanattempt toidentify all toxic pollutants, determine theeffectsofeach pollutant individually, andthen attempt toassesstheir collective effect.

The scientific basisfor using blological techniques hasadvanced significantly in recentyearn.There is now ageneral consensusthat an evaluation ofeffluent toxicity, when adequately related toinstream conditions, canprovide avalid indication ofreceiving system impacts. 

### This information can beuseful in developing regulatory requirements to protect aquatic life, especially when 

### datafromtoxicity testing areanalyied in conjunction with chemical and ecological data.Generic human health 

### effects methods,suchastheAmes mutagenicity test.andstructure-activity relationship techniques areshowing promise andshould beusedto identify potential hazards.However, poliutantspecific techniques arethebestway to evaluate andcontrol human health hazards atthis time.

Biological testingofeffluents isan important aspectofthewater qualitybasedapproach for controlling toxic pollutants. Effluent toxicity data in conjunction with other data canbeused toestablish control priorities, assess compliance with 

### Statewater quality standards, and set 

### permit limitations to achieve thosestandards. All Stateshave water quality standards which include narrative statementsprohibiting the discharge oftoxic materials in toxic amounts.A few Statestandards have criteria morespecific than narrative criteria [for example, numerical criteria for specific toxic pollutants oratoxicity criterion toachieve designated uses).In Stateswhere numerical criteria arenot specified, ajudgment by the regulatory 

### authority isrequired tosetquantitative water quality-based limits onchemicals andeffluent toxicity toassure

### 9018 Federal Register 1 

### Vol. 49, No. 

### 48 1 Friday, March 9, 1984 I Notices

. __ 

### compliance with water qualit> standards.

Note.-Section 308 of the 

### Acttrnd corresponding State statutes authorizca WA 

### andtheStalesto require of the owner/ operator any information reasonably required lo determine permit limits and to determine 

### compliance withstandards orpermitlinlik Kological methods are specifically mentioned. Toxicity permit limits arp authorized under Secllon 301 and 4(32nnrl supported by Section 101. Application



### This policy applies toEPAand the States.Thepolicy addressestheuseof chemical and biological methodsfor assuring that effluent dischargesare regulated in accordancewith Federal and Staterequirements. This policy was prepared. in part, in responseto concerns raised by litigants tothe Consolidated Permit Regulations [seeFR 52079,November 18.1982), 

### Useofthese methodsfordeveloping water quality standards andtrend monitoring are discussedelsewhere (see48 

### FR51400. November 8,1983 

### andBasic Water Monitoring Program 

### EPA-440/9-76-025). This policy ispart ofEPA’swater quality-based control programanddoes notsupersedeother regulations, policy. and guidance 

### regarding use attainability, site-specific criteria 

### modification, wasteload allocation. and water quality management. fmplementotion 

### Slate Role

The control oftoxic substancesto protect water quality mustbedone in 

### thecontext oftheFederal-State partnership. EPAwill work cooperatively with the States in 

### identifying pbtential water quality standards violations. assembling relevant data,developing appropriate testing requirements. determining whether standards arebeingviolated, anddefining appropriate permit limits.

No&.-Under sections 303 and 401 of the 

### Act.States are given primary responsibility for developing water quality standards and limits to meet those standards. FPA’R role is to review the Stale standards and limits and develop revised or additional standards or limits as needed to meet the requirements of the Act. 

### Integration of Approaches



### The typeoftesting that is most appropriate for assessingwater quality impacts dependson 

### thetype ofeffluent and discharge situation. EPA recommendsthat anintegrated approach, including both biologictll and chemical techniques. beusedtoassess and control water quality. The principal advantages ofchemical-specific techniques arethat (I) chemical analyses areusually lessexpensive than biological measurementsin simple cases; (21treatment systemsaremore easily designedtomeetchemical requirements than’toxicity requirements: and (3)human health hazards and bioaccumulative pollutants canbestbe addressedatthis time bychemicalspecific analysis. The principal advantagesofbiological techniques are Ihal (tJtheeffectsofcomplex discharges ofmany known and unknown constituents canbemeasured only bybiological analyses; (21 bioavailability ofpollutants after discharge isbestmeasuredby toxicity testing: and (3)pollutants forwhich thereareinadequate chemical analytical methodsorcriteria canbeaddressed.

Pollutant-specific chemical analysis techniques should be used where 

### discharges contain few, well-quantified pollutants and theinteractions and effectsofthepollutants areknown. In addition, pollutant-specific techniques should be used 

### where health hazards areaconcern or bioaccumulation is suspected.Biological techniques should beusedwhere effluents arecomplex or where 

### thecombined effectsofmultiple discharges areofconcern. EPA recognizesthat in many casesboth typesof analysis 

### mustbeused. Testing Requirements Requirementsfor dischargers*to collect information toassessattainment ornonattainment ofStatewater quality standards will beimposedonly in selectedcaseswhere thepotential for nonattainment ofwater quality standards exists. Where water quality problems aresuspectedbut there isa strong indication that complying with BCT/BAT will sufficiently mitigate the impacts.EPArecommendsthat applicable permits include testing requirements effective after BCT/BAT compliance andreopenerclauses allowing reevaluation ofthedischarge.

The chemical, physical, and biological testing tobeconducted by individual dischargers should bedetermined ona case-by-casebasis. In makingthis determination, many 

### factors must 

### be considered, including thedegreeof impact.thecomplexity andvariability of thedischarge,thewater body typeand hydrology, thepotential for human health impact. theamount ofexisting data,thelevel ofcertainty desired in the water qualily assessment,other sources ofpollutants, andtheecologyof the 

### receiving water. Thespecific data neededtomeasuretheeffectthat a discharger hasonthereceiving water will vary according totheseandother factors. 82-3 An assessmentofwater quality should, totheextent practicable, include other point and nonpoint sourcesof pollutants if thesourcesmaybe contributing tothe impacts. Special 

### attention should befocusedonPublicly Owned Treatment Works (POTW’s) with asignificant contribution of industrial waste-water. Recentstudies have indicated that suchPOTW’s are cJftel1 SignifiCank SOUrCeS Of bXiC 

### materials. When developing 

### monitoring requirements. interpreting data,and determining limitations. permit engineersshould work closely with water quality staff atboth theStateand Federal Irvels.

A discharger mayberequired to provide data upon request undersection 

### 308of theAct, orsucharequirement maybeincluded in its NPDESpermit. The development of afinal assessment mayrequire several iterations ofdata collection. Where potential problems 

### are identified, EPAortheStatemay require monitoring 

### todetermine 

### whether more information isneededconcerning 

### water. quality effects. Useof Data

Chemical, physIcal. andbiological datawill beusedtodetermine whether, after compliance with BCT/BAT requirements. therewill beviolations of Statewater quality standards resulting fromthedischarge(s).The narrative prohibition of 

### toxic materials in toxic amounts contained in all State standards is the 

### basisfor this determination taking into account the designated useforthereceiving water. Forexample. dischargestowaters classified forpropagation ofcold water fish should beevaluated in relation to acuteandchronic effectsoncold water organisms.potential spawning areas, andeffluent dispersion. Setting Permit Limikions



### Whereviolations ofwater quality standards exist orareprojected, the Stateand EPAwill determine pollution control requirements that will attain the receiving water 

### designated use.Where effluent toxicily isanappropriate control parameter, permit limits on effluent toxicity should bedeveloped. 4 suchcases,EPAmayalso iequire a permittee toconduct atoxicity reduction evaluation. Atoxicity reduction evaluation isaninvestigation conducted within aplant ormunicipal system 

### to isolate the sources of 

### effluent toxicity, specific causative pollutants if possible, anddetermine theeffectiveness of pollution control options in reducing the effluent toxicity. If specific chemicals areidentified as 

### thecauseofthewater

### F&al Register / Vol. 49, No. 49

### :/ Friday, March 9, 1984 } Notices

- 

### 9019
quality standards violaliori. these individual poWants should belimited. If atoxicity reduction evaluation demonstrates that limiting apindicator parameter will ensure 

### attainment ofthe water quality-based effluent toxicity requirement. limits ontheindicator parameter should beconsidered in lieu of limits oneffluent toxicity. Such indicator limits are 

### not limits on causative pollutants but limits demonstrated toresult in aspecific toxicity reduction. Monitoring



### Where pollution control requirements areexpressed in termsofachemical or toxicological piirameter, compliance monitoring mustinclude monitoring for that parameter. 

### If anindicator parameter is usedbasedontheresults ofatoxicity reduction evaluation, periodic toxicity testing mayberequired toconfirm theadequacyofthe indicator. Where biological datawere usedto develop awater quality assessmentor where thepotential forwater quality standards violations exist. biological monitoring (including instream monitoring) mayberequired toensure continuing compliance with water quality standards.

EPAbelieves that theintelligent application ofanintegrated strategy usingboth biological andchemical techniques forwater quality assessment will facilitate thedevelopment of appropriate controls and theattainment ofwater quality standards. W’A looks forward IOworking with theStatesin a spirit ofcooperation lofurther refine thesetechniques.

Policy sipned February 3. 1984 

### byjackE. 

### Ravan. As&ant administrator for Water. Dated: Febrwry 16. 1%. jack E. Raven. As~r’stonf .4hm,nisfmtcrfor Litter
IFII 0~ M-twS Fllkd 3-844 1.45 ,ml lll.UYG CODE sso4o-Y



### B-24

# APPENDIX 

# B-3
REGULATIONS FOR

# TOXICSCONTROL

### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460



# AUG 21 I989 OFFICE OF WATER



## MEMORANDUM SUBJECT: New Regulations Governing Water Quality-Based Permitting intheNPDES Permitting Program FROM: James R.Elder, Director 

## of Water Enforcement

TO: Water Management Division Directors Regions I - X

On May 26, 1989 the Deputy Administrator signed regulations that implement section 304(1) of the CWA. The regulations became effective upon his signature and were published in the Federal Register on June 2, 1989 (54 Fed. Req. 23868). This rulemaking also clarified and reinforced EPA's existing regulations governing water quality-based permitting. The purpose of this memorandum is to describe the significance of these clarifications to EPA's baseline water quality-based permitting regulations. CHANGESTO 40 C.F.R. PART 122 Section 122.44 covers the establishment of limitations, standards, and other permit conditions in NPDES permits. Subsection (d) covers water quality standards and state requirements. Prior to the promulgation of these new regulations the subsection was non-specific, requiring only that NPDES permits be issued with requirements more stringent than promulgated effluent guidelines as necessary to achieve water quality standards. Wehave strengthened considerably the requirements of §122.44(d). The new language is very specific and requires water quality-based permit limits for specific toxicants and whole effluent toxicity where necessary to achieve state water quality standards. The following is a section-bysection description of the new requirements.

B-3-1

## 2

1. $122.44(d)(l)(i) This new paragraph provides that all pollutants that cause, have the reasonable potential to cause, or contribute to an excursion above a water quality standard must be controlled to achieve all applicable water quality standards, including narrative water quality criteria. Weadded this paragraph so that our regulations would reflect EPA's approach to water quality-based permitting.
2. $122.44(d)(l)(ii) Subparagraph (ii) of the new regulations requires the states to use valid procedures to determine whether a discharge causes, has the reasonable potential to cause, or contributes to an excursion above a water quality standard. These procedures must account for existing controls on point and nonpoint sources of pollution, the variability of the pollutant in the effluent, the sensitivity of the test species (when evaluating whole effluent toxicity), and where allowed by state water quality standards, the dilution of the effluent in the receiving water. The purpose of this new regulation is to require the states to use technically valid procedures when determining whether a discharge is exceeding a numeric or narrative water quality criterion. When the permitting authority determines, using these procedures, that a discharge causes, has the reasonable potential to cause, or contributes to an excursion above a water quality criterion, that permit must include one or more water quality-based effluent limits established under subparagraphs (iii) - (vi). Subparagraphs (iii) and (iv) deal with water quality-based limitations where the state has numeric water quality criteria: subparagraphs (v) and (vi) deal with a state's narrative water quaity criteria. 3. $122.44(d)(l)(iii) This paragraph requires NPDES permits to include effluent limitations for every individual pollutant that causes, has the reasonable potential to cause, or contributes to an excursion above a numeric water quality criterion. Thus, when a state has adopted a water quality criterion for an individual pollutant and the state determines under subparagraph (ii) that an effluent limit is necessary, subparagraph (iii) requires an effluent limit for that individual pollutant.
4. 3122.44(d)(l)(iv) Subparagraph (iv) requires effluent limitations on whole effluent toxicity when a discharge is exceeding a state numeric criteria for whole effluent toxicity. This paragraph is applied

B-3-2

## where a state has adopted a numeric criterion for whole effluent toxicity (e.g. a discharge must achieve an LC50 of 50% or higher).
5. $122.44(d)(l)(v) When the state determines that a discharge exceeds a narrative water quality criterion, subparagraph (v) requires effluent limitations on whole effluent toxicity. If, however, chemical-specific effluent limitations are demonstrated to be sufficient to achieve all applicable water quality standards, then subparagraph (v) allows the permitting authority to forego a limitation on whole effluent toxicity. It may be necessary for you to work with an individual state to ensure that they have the necessary protocols to support whole effluent toxicity limits.
6. $122.44(d)(l)(vi) Where an actual or projected excursion above a narrative water quality criterion is attributable to a particular pollutant, but the state has not adopted a water quality criterion for the pollutant of concern, this new regulation requires water quality-based effluent limitations which will control the pollutant of concern. Subparagraph (vi) establishes three options for developing such limitations. Under these options, a state may: 1) calculate a numeric criterion for the pollutant: 2) use EPA's water quality criterion for the pollutant of concern; or 3) establish effluent limits on an indicator parameter. By an indicator parameter we mean a pollutant or pollutant parameter for which control of this indicator will result in control of the pollutant of concern. For example, it may be shown that a more stringent control on total suspended solids will reduce discharge of a metal to a level which achieves the water quality standard. Subparagraph (vi) also sets out four provisions which must be met to allow the use of an indicator: 1) The permit must identify which pollutants are intended to be controlled by a limit on the indicator parameter.
2) 

## The fact sheet must set forth the basis for the limit, including a finding that compliance with the limit will result in 

## controls on the pollutant of concern that are sufficient to achieve the water quality standard. 3) The permit must require all monitoring necessary to show continued compliance with water quality standards.

0-3-3

## 4 - 4) The permit must contain a reopener clause allowing for changes in the permit as needed to achieve water quality standards. A state's narrative water quality criterion serves as the legal basis for establishing such effluent limits.
7. #122.44(d)(l)(vii) Subparagraph (vii) requires that all water quality-based effluent limitations adhere to two fundamental principles: 1) the effluent limitations must be derived from and comply with all applicable water quality standards: and 2) the effluent limitations are consistent with the assumptions and requirements of an applicable wasteload allocation (WLA) if a WLA is available for the pollutant. CHANGESTO 40 C.F.R. PART 123 We amended the permit objection regulations at 40 C.F.R. $123.44 to reflect the amendments to $122.44(d)(l). Under $123.44(c)(8) EPA may now object to a state-issued permit if the permit does not meet the requirements of $122.44(d)(l). Thus, if a state does not use technically sound procedures for evaluating the need for water quality-based effluent limitations then EPA may object to the permit. Also, if a state fails to include chemical-specific or whole effluent toxicity limitations in a permit as required by paragraphs (iii) - (vi), then EPA may object to the permit. Finally, if a water quality based effluent limitation is not derived according to the principles in subparagraph (vii) then EPA may object to the permit. If a state's surface water toxics control program is not adequate to implement these requirements, the new regulations at 40 C.F.R. $123.63 expand EPA's criteria for withdrawing a state's NPDESprogram. Under the new regulations ($123.63(a)(S)), EPA may withdraw a state's NPDESprogram if the state fails to develop an adequate regulatory program for developing water quality-based effluent limitations. In November 1987, Headquarters provided procedural and technical guidance to the Regions on conducting state toxic8 control program reviews to assess the adequacy of state water quality-based control programs. This guidance sets guidelines for assessing whether or not a state's regulations, policies, and technical guidance constitute an adequate program. The significance of these additions to Part 123 is twofold. First, the Regions must issue permits which comply with these requirements and must work with the NPDES states to insure they also issue permits which comply with these regulations. If the states do not issue permits consistent with Part 123, the Region must veto insufficient permits and work with the states to

B-34

## reissue the permits with water quality-based effluent limitations which achieve water quality standards. The specific requirements in $122.44(d) are structured in a way that implements EPA's Policy for the Development of Water Quality-Based Permit Limitations for Toxic Pollutants (49 Fed. Req. 9016 March 9, 1984). Second, Regions will need to look closely at each state's surface water toxics control program to ensure that the state's regulations, policies and technical guidance result in the consistent and comprehensive development of NPDES permits which achieve the state's water quality standards. Where this does not occur, each Region should work with the state to rectify the problem and, after these negotiations and where necessary, investigate the possibility of withdrawing the NPDES program. I hope these regulations will assist you in developing water quality-based effluent limits and will support your efforts to implement surface water toxic8 control programs. If you have questions or need more information about these requirements, please contact Cynthia Dougherty at FTS 475-9545 or have your staff contact Rick Brandes at FTS 475-9537.

cc: Permits Branch Chiefs, Regions I - X Martha Prothro, OWRS

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### 23868 Federal Register / Vol. 54, No. 105 

### / Friday, June 2, 1989 

### / Rules 

### and Regulations

ENVIRONMENTAL PROTECTION AGENCY [FRL-35574 

### 40CFR plrtr 122,123 d 130
Nstlonal Pollutant Dkchrr@ Ellminatlon System; Sum Wdar Toxic8 Control Program AOENCY: 

### JZnviranmentaIProtection Agency. ACTIONFinal Rule. andStandards, (WH-553), 

### U.S. Environmental Protection Agency, 4.01 M StreetSW.,Washington, DC2OM0,(202) 382-7056. 

### The Public recordforthis regulation ieavailable attheEPA library, M~~KM, U.S.Environmental Protection Agency, 401M StreetSW., Washington, DC20480.

SUMMARY: Today’s action 

### amendsParts 122,123.and 130

### ofEPA’sregulations. The regulations clarify EPA’ssurface water toxica control program, and 

### incorporate section 308(a)of the 

### Water Quality Act of 1987 into EPA’s toxics 

### control program.Section308[a)ofthe Water Quality Act addedsection 304(l) totheCleanWater Act [hereafter referred toassection 304(l)).Section 304(l)requires thestatestoidentify those 

### waters that are adversely affected 

### bytoxic, conventional, and nonconventional pollutants, and requires thestatestoprepare individual control strategies 

### that will control point sourcedischarges oftoxic pollutants. Thestates mustsubmit lists ofwaters and individual control strategiestoEPA for review, and if EPAdisapproves a state’sdecision with respecttoa list or 

### anindividual control strategy, 

### then EPA must implement therequirements of section 

### 304(l)in cooperation with the state.EPAandthestatesmust accomplish thetasksin section 304(l) according toanambitious seriesof deadlines. Today’s regulations will strengthen Stateand Federal controls over dischargestotoxic pollutants, and will assist EPAandthestatesin satisfying therequirements ofsection 304(l) 

### oftheCWA. EFFECTIVE DATE These regulations 

### shall beeffective onMay 243,1989 at 1:fXl 

### p.m. Eastern Daylight SavingsTime. In accordance with 40CFR23.2,EPA hereby specifies that theseregulations shall beconsidered final agencyaction for purposesofjudicial review at 1:OO p.m.EasternDaylight SavingsTime on May 26.1989. FOR FURTHER INFOAYATION COWACE 

### PaulConnor, ProgramDevelopment Branch,Office ofWater Enforcement andPermits, @N-338),US. Environmental Protection Agency, 401M 

### Street,SW.,Washington, DC20480, (202)475-9537,orJudith Leckrone. AssessmentandWatershed Protection Division, Office of 

### Water Regulations

B-3-6

### Faded RQW- / Vol. 5% No. 106 / Friday, June Z,~SSS / Rules and Reguiatiorm 2x95

PART In--EPA ADMINISTERED Pf%MlT PfWGRAMS THE NATIONAL

1.The authority citation 

### for Part 122 continuer toread aufollows:

AutbaitY: Tba Clean Water Act. 33USC. 1251et req.



### 2.Section 1222is amended byadding inunw~betical order anew definition aa

.
om.2 D@fhhma

l l l l t



### Wholeeffruent toxicity mean0the aggregate toxk effect 

### of aneffluent 

### measureddirectly by atoxicity test.

3.Paragraph [d)(l) of 0IZZ.M is revised toread asfollows: 8w2U Ed@bkhgIlmltr(knr, rtmdudr,~-P.mlto#lditkn ~ww&--msproomy8e.

. l l

. l



### (4

. l

. (11

### Achieve wrter 

### quality standards established under rection 303ofthe CWA including Statenarrative criteria for water qualitv.

.

(I)Limitition~ mustcontrol all pollutants orpollutant parameters (either conventional. nonconventional ortoxic pollutants) which the Director’ determines areormay bedischarged at alevel which will cause,have the reasonable potential tocatrae.or contribute toanexcursion above any Statewater quality standard, including Statenarrative criteria forwater qualtty.

(ii) When determining whether a discharge causes,hasthe reasonable potential tocause,orcontributes toan in-&ream excursion above anarrative or 

### numeric criterie within aStatewater quality standard. thepermitting authority shell use 

### procedures which account forexisting controle onpoint and nonpoint sourcesofpollution, the variability ofthepollutant orpollutant parameter in theeffluent, the Beneitivity ofthespeciestotoxicity testing (when evaluating whole effluent toxicity), and where appropriate, the dilution 

### ofthe effluent in thereceiving 

### water.

(iii) When tbepermitttng authority determines, uain~theprocedures in paragraph (d)(l)(ii) ofthis section. thst a discharge causes,haethereasonable potential tocause,orcontributes toan in&ream excursion abovetheallowable ambient concentration of aState numeric criteria witbin aStatewater quality standard for an individual pollutant, thepermit must contain effluent limits for that pollutant.

(iv) When thepermitting authority determines; wingt theprodedurea in paregraph (d)(l)(ii) ofthis section, that a discharge causea,haathe reasonable potential tocause,orcontributes toan in-dream excursion above thenumeric criterion forwhole effluent toxicity, the permit mustcontain effluent limit8 for whole effluent toxicity.

Iv1¢ aaDrovided in thie rubpamgr~ph, Ghen thepermitting authority deterrntnea,using the procedurea in paragraph (d)(l)(ii) ofthis recttoa toxicity testing data,or other information, 

### tbat adischarge causes, 

### has thereasonable potential tocatme,or contributes toan in&ream excursion above anarrative criterion within an applicable Statewater quality standard, thepermit mustcontain effluent hmita forwhole effluent toxicity. Limits on whole effluent toxicity arenot necessary where tbepermitting authority demonstrates in thefact sheetor statement ofbasisofthe NPDESpermit, using theprocedure8 in paragraph (d)(l)@) ofthis section, that chemicalspecific limita for theeffluent are sufficient toattain and maintain applicable numeric and narrative State water quality etandarda.

(vi) Where aStatehasnot established awater quality criterion for aspecific chemical pollutant that iapresent in an effluent ataconcentretton that cnuae8, hasthe reaeonable potential tocatme,or contributes to anexcursion above a narrative criterion within anapplicable Statewater quality standard, the 0-3-7 permitting authority muatestablish effluent hmits ueing oneormoreofthe following optione:

(A) Establteh effluent limita ustnga calculated numeric water quality criterion for thepollutant which the permitting authority demonstrates will attain and maintain applicable narrative water quality criteria andwill fully protect thedesignated use.Sucha criterion maybederived wing a 

### proposed Statecriterion, oranexplicit Statepolicy or regulation interpreting its narrative water quality criterion, supplemented with other relevant information which may include: EPA’s 

### Water Quality Standards Handbook, October ‘166% risk assessmentdata, exposure data, information about the pollutant from theFoodand Drug Administration, andcurrent EPAcriteria documents; or

(B)Establish effluent limits onacaaeby-case basis, using EPA’swater quality criteria, published under section m(a) oftheCWA, supplemented where necessary by other relevant information; or(C)Establish effluent limitatione on an indicator parameter for thepollutant of concern, provided:

(1)Tbepermit identifies which pollutanta areintended tobecontrolled bytheuseoftheeffluent limitation;

(2)The fact sheetrequired by P1~~6 setsforth thebasisfor thelimit, including afinding that compliance with theeffluent limit onthe indicator parameter will result 

### in controls onthe pollutant ofconcern which aresufficient toattain and maintain applicable water quality standards;

(3)

### The permit requires ill effluent and ambient monitoring necessary toshow that during thetermofthepermit the limit onthe indicator parameter continuea toattain and 

### maintain applicable water quality standards; and

(4)The permit contains areopener clause allowing tbepermitting authority tomodify or revoke and reissue the Permit if the limit8 onthe indicator parameter nolonger attain and maintain applicable water quality standards.

(vii) When developing water qualitybasedeffluent limits under this EEqh$e permitting authority shall

(A)The level ofwater quality tobe achieved by limite 

### onpoint sources established under this paragraph ie derived from,and complies with all applicable water quality standards; and

(B)Effluent bmttedeveloped to protect anarrative water quality criterion, anumeric water quality criterion, orboth, ereconsistent with the aesumptiona 

### and requirements ofany available wasteload allocation for the

### Feded Register / Vol. 64, No. 105 / 

### Friday, June 2. 1989/ Rules 

### and Regulations
discharge prepared bytheSteteand approved by EPApursuant to40CFR 130.7.

. l

. . l



### 4.The title ofparagraph (eB] of 8 12244 is revised toread asfollows: . t . . .

(e)Technology-based controls for toxic pollutants. l l l PART 123-STAlE PROORAM REOWREYENTS



### 1.Theauthority citation for Part 123 continues toreadaa

### follows:

Authority:CleanWaterAct,33U.S.C. 1251 etseq.

2.Section 123.4 ieamendedby adding paregraph [C)(S)toread as follows:
0122.44 EPAmfhwofmldoqecthsto stat. pBmtl8.

l +

. . l



### # ;ha kffluent limits ofapermit fail tosatisfy the requirement8 of40CFR 122.&(d).

. . . t l



### 3.In 0123.46paragraph (a)isrevised and paragraphs (cl, (d).(e)and (fj are added.asfollows:
0 122A6 IndlvmJsl clbbor 8tratoglaa



### (a)Not later than February 4,1989. eachStateshall submit totheRegional Administrator for review, approval, and implementation anindividual control strategy for eachpoint source identified bytheStatepursuant tosection 304(1)(1)(C) oftheAct which will produce areduction in thedkharge of toxic pollutants from thepoint source8 

### identified under section 304(l)(l)(C) through theestablishment ofeffluent limitatione under section 402ofthe CWA andwater quality standards undersection 303(c)(2)(B)oftheCWA, which reduction issufficient, in combination with existing controla on point and nonpoint sourcesofpollution, toachieve theapplicable water quality standard assoonaspossible. but not later than threeyears 

### after thedateof theestablishment ofsuchstrategy.

l l

. . .



### (cl Forthepurposesof this 

### section the term individual control strategy, asset forth in section 304(l)oftheCWA. meansafinal NPDESpermit with supporting document& 

### onshowing that effluent 

### limits acsconsistent with an approved wasteload allocatfon, orother documentation which shows that applicable water quality standards wlll bemetnot later than threeyears after the individual control strategy ia established. Where aStateis unable to issueafinal permit onorbefore Febmary ~,ISICI,auindividual kntrol strategy maybe adraft per&t with an attached schedule (provided theState meetstheschedulefor iesu@ thefinal permit) irdlcating that thepermit will be 

### issuedonorbefore February 4.1990.If a point sourceiseubjecttosection 304(I)(l)(C) oftheCWA and isalso subject toanon-eite responseaction under section8 101or 108of the 

### Comprehensive Environmental Re8pon8e.Compensation, and Liability Act of 1980(CERCLA), (42 

### U.S.C.

### 8801 et seq.),anindividual control strategy may bethedecision document (which incorporates theapplicable orrelevant and appropriate requirements 

### underthe CWA) prepared under sections 104or 106ofCERCLAtoaddree8thereleaseor threatened releaseofhazardow substances totheenvironment.

(d]A petition submitted pursuant to section 304(l)(3)oftheCWA mustbe submitted totheappropriate Regional AdminMrator. Petitions mustidentify a 

### waterbody in sufficient detail sothat EPA isabletodetermine thelocation and boundaries ofthewaterbody. The petition mustalso identify thelist or lists forwhich thewaterbody qualifiis. andthe petition 

### mustexplain why the waterbody satisfies thecriteria for listing under CWA section X&%(l) and 40 

### CFR13mO(d)(8).

(e)If theRegional Administrator disapproves oneormoreindividual control strategies,orif eStatefails to provide edequatepublic notice and an opportunity tocommentonthe ICSs. then,not later than June4.lseS. 

### the Regional Administrator shall give a notice ofapproval ordisapproval ofthe individual 

### control strategies submitted byeachState 

### pursuant tothis section es follows:

(11 The notice ofapproval or dlsapproval given under this 

### paragraph shall include thefollowing:

(i)The nameand addressof theEPA office that reviews the State’8 

### submittals.

(ii) A 

### brief description ofthesection 304(l)process.

(Iii) A list of ICSsdisapproved under this section and afinding that the ICES 

### will not meetall applicable review criteria under this 

### section andsection 304(l)ofthaCWA.

(iv) If theRegional Administrator determines that aState did not 

### provide adequate 

### pubklcnotice and an opportunity tocqmmentonthewaters, point m or ICSsprepared pursuant tosection 304(I).orif theRegional Administrator choosea 

### toexercise his or herdiscr8tioa albt oftheICS8 approved under this section, and a B-3-8 5nding that the 

### ICSssatisfy all applicable review rsiteria.

iv) The location where interested 

### per---y -8 

### WA’S RCOrdSOf approval 

### enddisepprvvaL

(vi) The name.address,andtelephone number oftheperson attheRegional Office fromwhom interested persons mayobtain moreinformaffon.

(vii) Notice that written petitions or commentsareduewithin 120days.



### (2)The Regional Administrator shall provide thenotice ofapproval or disapproval given 

### under this paragraph tothe eppropriate StateDirector. The Regional Administrator ahalI publish a notice ofavailability, ln adaily or weekly newspaper with State-wide circulation or 

### In theFetied Register,for theno&e ofapproval ordisapproval. The Regional Administrator shall also provide written notice toeach discharger identified under section 

### 304(1)(1)(C), that EPAhaslisted the discharger under section 

### 3w(l)(l](C).

(3)A8soona8practicable but not later than June4.lSaa 

### theRegional Offices shall issuearesponseto pet&ions orcommentsreceived under section 304(f).The responseto commentsshall begiven in thesame mannerasthenotice described in paragraph (e)ofthis section except for thefollowing changes:



### (i)The liataof ICSsreflecting any changesmadepursuant tocommentsor petitions received.

(ii) A brief description oftbe subsequent stepsin thesection ~~(11 process.

(fjEPA8haIl review, andapprove 

### or disapprove, theindividual control strategies prepared under section 304(l) oftheCWA, using theapplicable criteria setforth in saction 304(l)ofthe CWA, and in 40CFRPart122,including P12214(d). At any time after the 

### Regional Administrator disapproves an ICS(orconditionally aproves a draft permit 

### asanES). theRegional Office may submit a

### written notification tothe Statethat theRegional Office intends to 

### issuethe KS. Upon mailing the notification, and notwithstanding any other reguIation. exclusive authority to issuethepermit passestoEPA.

4.Section 123.63isamendedby eddlng paragraph (a)(5)toreadas followa:

(a) ’ l l 

### (51WheretheStatefail8 

### todevelop an adequate regulatory 

### programfor developing watsr qua&y-based effluent lmts in NPDEspermit8.

# APPENDIXB-4 WHOLEEFFLUENT TOXICITY PERMITTINGPRINCIPLES ANDENFORCEMENT STRATEGY

### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON. D.C. 20460 January 25, 1989

OFFICE OF WATER
MEMORANDUM
SUBJECT: Enforcement Strategy WholeEffluent Toxicity Basic Permitting Principles and

FROM: Rebecca W. Hanmer, Acting Assistant Administrator Office of Water
TO: Regional Administrators

Since the issuance of the "Policy for the Development of Water Quality-based Permit Limitations for Toxic Pollutants" in March of 1984, the Agency has been moving forward to provide technical documentation to support the integrated approach of using both chemical and biological methods to ensure the protection of water quality. The Technical Support Document for Water Quality-based Toxics Control [September, 1985) and the Permit Writer's Guide to Water Quality-based Permitting for Toxic Pollutants (July, 1987) have been instrumental in the initial implementation of the Policy. The Policy and supporting documents, however, did not result in consistent approaches to permitting and enforcement of toxicity controls nationally. When the 1984 Policy was issued, the Agency did not have a great deal of experience in the use of whole effluent toxicity limitations and testing to ensure protection of water quality. We now have more than four years of experience and are ready to effectively use this experience in order to improve national consistency in permitting and enforcement.
In order to increase consistency in water quality-based toxicity permitting, I am issuing the attached Basic Permitting Principles for Whole Effluent Toxicity (Attachment 1) as a standard with which water quality-based permits should conform. A Workgroup of Regional and State permitting, enforcement, and legal representatives developed these minimum acceptable requirements for toxicity permitting based upon national experience. These principles are consistent with the toxics control approach addressed in the proposed Section 304(1) regulation. Regions should use these principles when reviewing draft State permits. If the final Section 304(1) regulations include changes in this area, we will update these principles as necessary. Expanded guidance on the use of these principles will be sent out shortly by James Elder, Director of the Office Of

B-4-1

## -2-

Water Enforcement and Permits. This expanded guidance will include sample permit language and permitting/enforcement scenarios. Concurrent with this issuance of the Basic Permitting Principles, I am issuing the Compliance Monitoring and Enforcement Strategy for Toxics Control (Attachment 2). This Strategy was developed by a Workgroup of Regional and State enforcement representatives and has undergone an extensive comment period. The Strategy presents the Agency's position on the integration of toxicity control into the existing National Pollutant Discharge Elimination System (NPDES) compliance and enforcement program. It delineates the responsibilities of the permitted community and the regulatory authority. The Strategy describes our current efforts in compliance tracking and quality assurance of self-monitoring data from the permittees. It defines criteria for review and reporting of toxicity violations and describes the types of enforcement options available for the resolution of permit violations. In order to assist you in the management of whole effluent toxicity permitting, the items discussed above will join the 1984 Policy as Appendices to the revised Technical Support Document for Water Quality-based Toxics Control. To summarize, these materials are the Basic Permitting Principles, sample permit language, the concepts illustrated through the permitting and enforcement scenarios, and the Enforcement Strategy. I hope these additions will provide the needed framework to integrate the control of toxicity into the overall NPDESpermitting program. I encourage you and your staff to discuss these documents and the 1984 Policy with your States to further their efforts in the implementation of EPA's toxics control initiative. If you have any questions on the attached materials, please contact James Elder, Director of the Office of Water Enforcement and Permits, at (FTS/202) 475-8488. Attachments

cc: ASWIPCA Water Management Division Directors

B-4-2

## EASIC PERMITTING PRINCIPLES FORWHOLEEFFLUENT TOXICITY

1. 

## Permits must be protective of water quality.

a. At a minimum, all major permits and minors of concern must 

## be evaluated for potential or known toxicity (chronic or acute if more limiting). b. Final whole effluent toxicity limits must be included in permits where necessary to ensure that State Water Quality Standards are met. 

## These limits must properly account for effluent variability, available dilution, and species sensitivity.

2. 

## Permits must be written to avoid ambiguity and ensure enforceability.

a. Whole effluent toxicity limits must appear in Part I of the permit with other effluent limitations. b. Permits contain generic re-opener clauses which are sufficient to provide permitting authorities the means to re-open, modify, or reissue the permit where necessary. Re-opener clauses covering effluent toxicity will not be included in the Special Conditions section of the permit where they imply that limit 

## revision will occur based on 

## permittee inability to meet the limit. Only schedules or other special requirements will be 

## added to the permit.

C. 

## If the permit includes provisions to increase monitoring frequency subsequent to a violation, it must be clear that the additional tests only determine the continued compliance status with the limit; they are not to verify the original test results. d. Toxicity testing species and protocols will be accurately referenced/cited in the permit.

3. 

## Where not in compliance with a whole effluent toxicity limit, permittees must be compelled to come 

## into compliance with the limit as soon as possible.

a. Compliance dates must be 

## specified. b. Permits can contain requirements for corrective actions, such as Toxicity Reduction Evaluations (TRW, but corrective actions cannot be 

## delayed pending EPA/State approval of a plan for the corrective actions, unless State regulations require prior approval. Automatic corrective actions subsequent to the effective date of a final whole-effluent toxicity limit will not be included in the permit. B-4-3

## ATTACHMENT1
Explanation of the Basic Permitting Principles The Basic Permitting Principles present the minimum acceptable requirements for whole-effluent toxicity permitting. They begin with a statement of the goal of whole-effluent toxicity limitations and requirements: the protection of water quality as established through State numeric and narrative Water Quality Standards. The first principle builds on the Technical Support Document procedures and the draft Section 304(l) rule requirements for determining potential to violate Water Quality Standards. It requires the same factors be considered in setting whole-effluent toxicity based permits limits as are used to determine potential Water Quality Standards violations. It defines the universe of permittees that should be evaluated for potential violation of Water Quality Stand-ids, L.Ad the,tfore possible whole-effluent limits, as all majors and minors of concern. The second permitting principle provides basic guidelines for avoiding ambiguities that may surface in permits. Wholeeffluent toxicity limits should be listed in Part I of the permit and should be derived and expressed in the same manner as any other water quality-based limitations (i.e., Maximum Daily and Average Monthly limits as required by Section 122.45(d)). In addition, special re-opener clauses are generally not necessary, and may mistakenly imply that permits may be re-opened to revise whole-effluent limits that are violated. This is not to imply that special re-opener clauses are never appropriate. They may be appropriate in permits issued to facilities that currently have no known potential to violate a Water Quality Standard; in these cases, the permitting authority may wish to stress its authority to re-open the permit to add a wholeeffluent limit in the event monitoring detects toxicity. Several permittees have mistakenly proposed to conduct additional monitoring subsequent to a violation to "verify" their results. It is not possible to verify results with a subsequent test whether a new sample or a split-sample which has been stored (and therefore contains fewer volatiles) is used. For this reason, any additional monitoring required in response to a violation must be clearly identified as establishing continuing compliance status, not verification of the original violation.

## - 2- The second principle also deals with the specification of test species and protocol. Clearly setting out the requirements for toxicity testing and analysis is best done by accurately referencing EPA's most recent test methods and approved equivalent State methods. In this way, requirements which have been published can be required in full, and further advances in technology and science may be incorporated without lengthy permit revisions. The third and final permitting principle reinforces the responsibility of the permittee to seek timely compliance with the requirements of its NPDES permit. Once corrective actions have been identified in a TRE, permittees cannot be allowed to delay corrective actions necessary to comply with water quality- based whole effluent toxicity limitations pending Agency review and approval of voluminous reports or plans. Any delay on the part of the permittee or its contractors/agents is the responsibility of the permittee. The final principle was written in recognition of the fact that a full-blown TRE may not be necessary to return a permittee to compliance in all cases, particularly subsequent to an initial TRF,. As a permittee gains experience and knowledge of the operational influences on toxicity, TREs will become less important in the day to day control of toxicity and will only be required when necessary on a case-specific basis.

B-4-5

### ATTACHMENT 

# 2

to the Cwce Watorba UEniorcm StratecnriQlc,hToxicsControl The me Modtormnt Strateuv for Contrd sets forth the Agency's strategy 

# for tracking compliance with and enforcing whole-effluent toxicity monitoring requirements, limitations, schedules and reporting requirements. The Strategy delineates the respective responsibilities of permittees and permitting authorities to protect water quality through the control of whole-effluent toxicity. It establishes criteria for the review of compliance data 

# and the quarterly reporting of violations to Headquarters and the public. The Strategy discusses the integration of whole-effluent toxicity control into our existing.fnspection and quality assurance efforts. It provides guidelines on the enforcement of wholeeffluent toxicity reguirements. The Strategy also addresses the concern many permittees share as they face the prospect of new requirements in their permit - the fear of indiscriminate penalty assessment for 

# violations that they are unable to control. The Strategy recognizes enforcement discretion as a 

# means of dealing fairly with permittees that are doing everything feasible to protect water quality. As 

# indicated in the Strategy, this discretion deals solely with the assessment of civil penalties, however, and is not an alternative to existing procedures for establishing relief from State Water Quality Standards. The Strategy focuses on the responsibility of the Agency and authorized States to require compliance with Water Quality Standards and thereby ensure protection of existing water resources.

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## 01/19/89

COMPLIANCE MONITORING AND ENFORCEMENT STRATEGY FORTOXICS CONTROL

I. 

## Background Issuance of 

## NPDESpermits now emphasizes the control of toxic pollutants, by integrating technology and water quality-based permit limitations, best management practices for toxic discharges, sludge requirements, and revisions to the pretreatment implementa- tion requirements. These requirements affect all major permittees and those minor permittees whose discharges may contribute to impairment of the designated use 

## for the rec'eiving stream. The goal of permitting is to eliminate toxicity in receiving waters that results from industrial and municipal discharges. Major industrial and municipal permits will routinely contain water quality-based limits for toxic pollutants and in many cases whole effluent toxicity derived from numerical and narrative water quality standards. The quality standards to establish NPDBS permit limits are discussed in the "Policy for the Development of Water Quality-based Permit Limits for Toxic Pollutants," 49FR 9016, March 9, 1984. The Technical Support Document for Water Quality- based Toxics Control, EPA X440/44-85032 September, 1985 and the .Permit Writer's Guide to Water Quality-Gased Permitting for Toxic Pollutants, Office of Water, May, 1987, provide guidance for interpreting numerical and narrative standards and developing permit limits. The Water Quality 

## Act (WQA) of 1987 (PL 100-4, February 4, 1987) further directs EPA and the States to identify waters that require controls for toxic pollutants and develop individual control strategies including permit limits to achieve control of toxics. The WQAestablished deadlines, for individual control strategies (February 4, 1989) and for compliance with the toxic control permit requirements (February 4, 1992). This Strategy will support the additional compliance monitoring, tracking, evalu

## ation, and enforcement of the whole effluent toxicity controls that will be needed to meet the requirements of the WQAand EPA's policy for water quality-based permitting. It is the goal of the Strategy to assure compliance with permit toxicity limits and conditions through compliance inspec- tions, compliance reviews, and enforcement. Water quality-based limits may include both chemical specific and whole effluent toxicity limits. Previous enforcement guidance (e.g., Enforcement Management System for the National Pollutant Discharge Elimination System, September, 1986: National Guidance for Oversight of NPDES Programs, May, 1987: Guidance for Preparation of Quarterly and Semi-Annual Noncompliance Reports, March, 1986) has dealt with

0-4-7

## -2-

chemical-specific water quality-based limits. This Strategy will focus on whole effluent toxicity limits. Such toxicity limits may appear in permits, administrative orders, or judicial orders.

II. Strategy Principles This 1)

2)


## 3)

4) strategy is based on four principles: Permittees are responsible for attaining, monitoring, and maintaining permit compliance and for the quality of their data. Regulators will evaluate self-monitoring data quality to ensure program integrity. Regulators will assess compliance through inspections, audits, discharger data reviews, and other independent monitoring or review activities. Regulators will enforce effluent limits and compliance schedules to eliminate toxicity. III. Primary Implementation Activities In order to implement this Strategy fully, the following activities are being initiated: A. Immediate development 1. The NPDES Compliance Inspection Manual was 

## revised in May 1988 to include procedures for performing chronic toxicity tests and evaluating toxicity reduction evaluations. An inspector training module was also developed in August 1988 to support inspections for whole effluent toxicity.
2. The Permit Compliance System (the national NPDES data base) was modified to allow inclusion of toxicity limitations and compliance schedules associated with toxicity reduction evaluations. The PCS Steering Committee 

## will review standard data elements and determine if further modifications are necessary. 3. Compliance review factors (e.g., Technical Review Criteria and significant noncompliance definitions) are being proposed to evaluate 

## violations and appropriate response. 4. A Quality Assurance Fact Sheet has been developed (Attached) to review the quality of toxicity test results submitted by permittees.

04-a

## -3-

5. The Enforcement Response Guide in the Enforcement Management System will be revised to cover 

## the use of administrative penalties and other responses to violations of 

## toxicity controls in permits. At least four types of 

## permit conditions are being examined: (1) whole-effluent toxicity monitoring (sampling and analysis), (2) whole effluent toxicity-based permit limits, (3) schedules to conduct a TRE and achieve compliance with water quality-based limits, and (4) reporting requirments. B. Begin development in Spring 1989 With the assistance of the Office of 

## Enforcement and Compliance Monitoring (OECM), special remedies and model forms will be developed to address violations of toxicity permit limits (i.e., model consent decrees, model complaints, revised penalty policy, model litigation reports, etc.) IV. Scope and Implementation of Strategy A. Compliance Tracking and Review
1. Compliance Tracking The Permits Compliance System (PCS) will be used as the primary system for tracking limits and monitoring compliance with the conditions in NPDES permits. Many new codes for toxicity testing have already been entered into PCS. During FY 89, headquarters will provide additional guidance to Regions and States on PCS coding to update existing documentation. The Water Enforcement Data Base (WENDB) requirements as described in the PCS Policy Statement already require States and Regions to begin incorporating toxicity limits and monitoring information into PCS. In addition to guidance on the use of PCS, Headquarters has prepared guidance in the form of Basic Permitting Principles for Regions and States that will provide greater uniformity nationally on approaches to toxicity permitting. One of the major problems in the tracking and enforcement of toxicity limits is that they differ greatly from State-to-State and Region-to-Region. The Permits Division and Enforcement Division in cooperation with the PCS Steering Committee will establish standard codes for permit limits and procedures for reporting toxicity results based on this guidance.

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## -4-

Whole effluent toxicity self-monitoring data should undergo an appropriate quality review. (See attached checklist for suggested toxicity review factors.) All violations of permit limits for toxics control should be reviewed by a professional qualified to assess the noncompliance. Regions and States should designate appropriate staff.
2. Compliance Review Any violation of a whole effluent toxicity limit is of concern to the regulatory agency and should receive an immediate professional review. In terms of the Enforcement Management System (EMS), any whole effluent violation will have a violation review action criterion (WAC) of 1.0. However, the appropriate initial enforcement response may be to require additional monitoring and then rapidly escalate the response to formal enforcement if the noncompliance persists. Where whole effluent toxicity is based on a pass-fail permit limitation, any failure should be immediately targeted for compliance inspection. In some instances, assessment of the compliance status will be required through issuance of Section 308 letters and 309(a) orders to require further toxicity testing. Monitoring data which is submitted to fulfill a toxicity monitoring requirement in permits that do not contain an independently enforceable whole-effluent toxicity limitation should also receive immediate professional review. The burden for 

## testing and biomonitoring is on the permittee; however, in some instances, Regions and States may choose to respond to violations through sampling or performance audit inspections. When an inspection conducted in response to a violation identifies noncompliance, the Region or State should initiate a formal enforcement action with a compliance schedule, unless remedial action is already required in the permit. B. Inspections EPA/State compliance inspections of all major permittees on an annual basis will be maintained. For all facilities with water quality-based toxic limits, such inspections should include an appropriate toxic component (numerical and/or whole effluent review). Overall the NPDES inspection and data quality activities for toxics control should receive greater emphasis than in the present inspection strategy.

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## -5-

1. Regional/State Capability
The EPA’s 

## "Policy for the Development of 

## Water Quality-based Permit Limits for Toxic Pollutants" (March 9, 1984 Federal Register) states that EPA Regional Administrators will assure that each Region has the full capability to conduct water quality assessments using both biological and chemical methods and provide technical assistance to the States. Such capability should also be maintained for compliance biomonitoring inspections and toxics sampling inspections. This capability should include both inspection and laboratory capability.
2. Use of Nonsampling Inspections Nonsampling inspections as either compliance evaluations (CEIs) or performance audits (PAIs) can be used to assess permittee self-monitoring data involving whole effluent toxicity limits, TREs, and for prioritization of sampling inspections.* As resources permit, PAIs should be Used to verify biomonitoring capabilities of permittees and contractors that provide toxicity testing selfmonitoring data. 3. Quality Assurance All States are encouraged to develop the capability for acute 

## and chronic toxicity tests with at least one fish and one invertebrate species for freshwater and saltwater if appropriate. NPDES States should develop the full capability to assess compliance with the permit conditions they establish. EPA and NPDES States will assess permittee data quality and require that permittees develop quality assurance plans. Quality assurance plans must be available for examination. The plan should include methods and procedures for toxicity testing and chemical analysis: collection, culture, maintenance, and disease control procedures for test organisms; and quality assurance practices. The

* 

## Due to resource considerations, it is expected that sampling inspections will be limited to Regional/State priorities in enforcement and permitting. Routine use of CEIs and PAIs should provide the required coverage.

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## -6-

permittee should also have available quality control charts, calibration records, raw test data, and culture records. In conjunction with the QA plans, EPA will evaluate permittee laboratory performance on EPA and/or State approved methods. This evaluation is an essential part of the laboratory audit process. EPA will rely on inspections and other quality assurance measures to maintain data quality. However, States may prefer to implement a laboratory certification program consistent with their 

## regulatory authorities. Predetermined limits of data accepta

## bility will need to be established for each test condition (acute/chronic), species-by-species.

c. Toxicity Reduction Evaluations (TREs) TREs are systematic investigations required of permittees which combine whole effluent and/or chemical specific testing for toxicity identification and characterization in a 

## planned sequence to expeditiously locate the source(s) of toxicity and evaluate 

## the effectiveness of pollution control actions and/or 

## inplant modifications toward attaining compliance with a permit 

## limit. The requirement for a TRE is 

## usually based on a finding of whole effluent toxicity as 

## defined in the permit. A plan with an implementation schedule is then developed to achieve compliance. Investigative approaches include causative agent identification and toxicity treatability.
1. Requiring TRE Plans TRE's can be triggered: 1) whenever there is a violation of a toxicity limit that prompts enforcement action or 2) from a permit condition that calls for a 

## toxicity elimination plan within a specified time whenever toxicity is found. The enforcement action such as a 309(a) administrative order or State equivalent, or judicial action then directs the permittee to take prescribed steps according to a compliance schedule to eliminate the toxicity. This schedule should be incorporated into the permit, an administrative order, or judicial order and compliance with the schedule should be tracked through PCS.
2. Compliance Determination Followup Compliance status must be assessed following the accomplishment of a TRE plan using the most efficient and effective methods available. These methods include site visits, self-monitoring, and inspections.

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## -7-

Careful attention to quality assurance will assist in minimizing the regulatory burden. The method of compliance assessment should be determined on a case-by-case 

## basis. D. Enforcing Toxic Control Permit Conditions Enforcement of toxic controls in permits depends upon a clear requirement and 

## the process to resolve the noncompliance. In addition to directly enforceable whole effluent limits (acute and 

## chronic, including absolute pass-fail limits), 

## permits have contained several other types of toxic control conditions: 1) "free from" provisions, 2) schedules to initiate corrective actions (such as TREs) when toxicity is present, and/or 3) schedules to achieve compliance where a limit is not currently attained. Additional requirements or schedules may be developed through 308 letters, but the specific milestones should be incorporated into the permit, administrative order or State equivalent mechanism, or judicial order to ensure they are enforceable.
1. The Quarterly Noncompliance Report (QNCR) Violations of permit conditions are tracked and reported as follows:

a. Effluent Violations Each exceedance of a directly enforceable whole effluent toxicity limit is of concern to the regulatory agency and, therefore, qualifies as meeting the VRAC requiring professional review (see section IV.A.2.). These violations must be reported on the QNCR if the violation is determined through professional review to have the potential to have caused a water quality impact. All QNCR-reportable permit effluent violations are considered significant noncompliance (SNC). b. Schedule Violations Compliance schedules to meet new toxic controls should be expeditious. Milestones should be established to evaluate progress routinely and minimize delays. These milestones should be tracked and any slippage of 90 days or more must be reported on the QNCR.

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## -8-

The following milestones are considered SNCwhen 90 days or more overdue: submit plan/schedule to conduct TRE, initiate TRE, submit test results, submit implementation plan/schedule (if appropriate), start construction, end conrtruction, and attain compliance with permit.

c. Reporting/Other Violations Violation of other toxic control requirements (including reports) will be reported using criteria that are applied to comparable NPDES permit conditions. For example, failure to submit a report within 30 days after the due date or submittal of an inaccurate or inadequate report will be reportable noncompliance (on the QNCR). Only failure to submit toxicity limit selfmonitoring reports or final TRE progress reports indicating compliance will be SNCwhen 30 days or more overdue. Resolution (bringing into compliance) of all three types of permit violations (effluent, schedule, and reporting/other) will be through timely and appropriate enforcement that is consistent with EPA Oversight Guidance. Administering agencies are expected to bring violators back into compliance or take formal enforcement action against facilities that appear on the QNCRand are in SNC: otherwise, after two or more quarters the facility must be listed on the Exceptions List. 2. Approaches to Enforcement of Effluent Limitations In the case of noncompliance with whole effluent toxicity limitations, any formal enforcement action will be tailored to the specific violation and remedial actions required. In some instances, a Toxicity Reduction Evaluation (TRE) may be appropriate. However, where directly enforceable toxicity-based limits are used, the TRE is not an acceptable enforcement response to toxicity noncoqiance if it requires only additional monitoring without a requirement to determine appropriate remedial actions and ultimately compliance with the limit.

If the Regions or States use administrative enforcement for violations of toxic requirements, such actions should require compliance by a date certain, according to a set schedule, and an

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## -9-

administrative penalty should be considered.1 Failure to comply with an Administrative Order schedule within 90 days indicates a schedule delay that may affect the final compliance date and a judicial referral is the normal response. In instances where toxicity has been measured in areas with potential impacts on human health (e.g., public water supplies, fish/shellfish areas, etc.), regions and states should presume in favor of judicial action and seek immediate injunctive relief (such as temporary restraining order or preliminary injunction). In a few highly unusual cases where the permittee has implemented an exhaustive TRE plan2, applied appropriate influent and effluent controls3, maintained continued compliance with all other effluent limits, compliance schedules, monitoring, and other permit requirements, but is still unable to attain or maintain compliance with the toxicity-based limits, special technical evaluation may be warranted and civil penalty relief granted. Solutions in these cases could be pursued jointly with expertise from EPA and/or the States as well as the permittee. Some permittees may be required to perform a second TRE subsequent to implementation of remedial action. An example of the appropriate use of a subsequent TRE is for the correction of new violations of whole effluent limitations following a period of

lFedera1 Administrative penalty orders must be linked to violations of underlying permit requirements and schedules. 2See Methods for Aquatic Toxicity Identification Evaluations, Phase I, Toxicity Characterization Procedures, EPA-600/3-88/035, Table 1. An exhaustive TRE plan covers three areas: causative agent identification/toxicity treatability; influent/effluent control; and attainment of continued compliance. A listing of EPA protocols for TREs can be found in Section V (pages 11 and 12). 3For industrial permittees, the facility must be well-operated to achieve all water quality-based, chemical specific, or BAT limits, exhibit proper 0 & M and effective BMPs, and control toxics through appropriate chemical substitution and treatment. For POTWpermittees, the facility must be well-operated to achieve all water quality-based, chemical specific, or secondary limits as appropriate, adequately implement its approved pretreatment program, develop local limits to control toxicity, and implement additional treatment.

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## - 10 -

sustained compliance (6 months or greater in duration) indicating a different problem from that addressed in the initial TRE. 3. Enforcement of Compliance Schedule and Reporting Requirements

In a number of instances, the primary requirements in the permits to address toxicity will be schedules for adoption and implementation of biomonitoring plans, or submission of reports verifying TREs or other similar reporting requirements. Regions and States should consider any failure (1) to conduct self-monitoring according to EPA and State requirements, (2) to meet TRE schedules within 90 days, or (3) to submit reports within 30 days of the specified deadline as SNC. Such violations should receive equivalent enforcement follow-up as outlined above.
4. Use of Administrative Orders With Penalties In addition to the formal enforcement actions to require remedial actions, Regions and States should presume that penalty AO's or State equiva- lents can be issued for underlying permit violations in which a formal enforcement action is appropriate. Headquarters will also provide Regions and States with guidance and examples as to how the current CWApenalty policy can be adjusted.
5. Enforcement Models and Special Remedies OWEPand OECMwill develop standard pleadings and language for remedial activities and compliance milestones to assist Regions and States in addressing violations of toxicity or water quality-based permit limits. Products will include model litigation reports, model complaints and consent decrees, and revised penalty policy or penalty algorithm and should be completed in early FY 1989.

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## - 11 -

v. Summary of Principal Activities and Products A.

B.

c.

D.

E. Compliance Tracking and Review guidance 1. PCS Coding Guidance - May, 1987; revision 2nd Quarter 1989 2. Review Criteria for Self-monitoring Data (draft attached) Inspections and Quality Assurance 1. Revised NPDES Compliance Inspection Manual - 

## May 1988. 2. Quality Assurance Guidance - 3rd Quarter FY 

## 1989. 3. Biomonitoring Inspection Training Module - August 1988. 4. Additions of a reference toxicant to DMRQAprogram - (to be determined) Toxic8 Enforcement
1. Administrative and Civil Penalty Guidance - 4th Quarter FY 1989 2. Model Pleadings and Complaints - 2nd Quarter 1989 3. EMS Revision - 2nd Quarter FY 1989 Permitting Consistency
1. Basic Permitting Principles - 2nd Quarter FY 1989 Toxicity Reduction Evaluations
1. Generalized Methology for Conducting Industrial Toxicity Reduction Evaluations - 2nd Quarter FY 1989 2. Toxicity Reduction Evaluation Protocol for Municipal Wastewater Treatment Plants - 2nd Quarter FY 1989

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## - 12 -

3. Methods for Aquatic Toxicity Indentification Evaluations

a. Phase I.

b. Phase II.

C. 

## Phase III. Toxicity Characterization Procedures, EPA-600/3-88/034- September 1988 Toxicity Identification Procedures, EPA-600/3-88/035- 2nd Quarter 1989 Toxicity Confirmation ProceduresEPA-600/3-88/036 d Quarter FY 1989

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# APPENDIXB-5 QUALITYCONTROLFACTSHEETS

### Attachment 

# Quality Control Fact Sheet for Self-Biomonitoring Acute/Chronic Toxicity Test Data

Permit No. Facility Name Facility Location Laboratory Investigator
Permit Requirements Sampling Location
Limit Type of Test
Test Results
LC50/EC50/NOEC/IC25 Quality Control Summary
Date of Sample
Control Mortality % Type of Sample
Test Duration
Test Organism Age

95 Percent Confidence Interval

Dates of Test
Control Mean Dry Weight Temperature maintained within ±2°C of test temperature? Yes No

Dissolved oxygen levels always greater than 40 percent saturation? Yes No Loading factor for all exposure chambers less than or equal to maximum allowed for the test type and temperature? Yes No
Do the test results indicate a direct relationship between effluent concentration and response of the test organism (i.e., more deaths occur at the highest effluent concentrations)? Yes No

B-5-1

# APPENDIXB-6
CASEDECISIONSONWHOLEEFFLUENT TOXICITY

# CASESUMMARY

Natural Resources Defense Council, Inc.v.EPA,859 F.2d159(D.C.Cir.1988).

This consolidated case, which arose from EPA’s promulgation of various National Pollutant Discharge Elimination System regulations, addresses a multitude of issues. The following paragraphs note issues particularly relevant to this document.

• The Court held that EPA has the authority to express permit limitations in terms of toxicity as long as the limits reflect the appropriate requirements of the Clean Water Act (CWA), as provided in 40 CFR 125.3(c)(4). The Court concluded that although toxicity appears to be an attribute of pollutants rather than a pollutant itself, the CWA (by means of the broad definition of “pollutant” in section 502(6)) authorizes the use of toxicity to regulate effluents.

• Industry asked the Court to address several other issues related to setting toxicity limitations (whether EPA failed to demonstrate the existence of a reliable methodology for setting toxicity limits and whether EPA’s use of toxicity to set water quality-based limitations to meet “narrative” State water quality standards represents an impermissible trespass on the State’s right to set water quality standards). However, the Court did not regard these issues to be adequately developed (“ripe”) for review in this case.


### •

• The Court disagreed with industry’s assertions that EPA’s 1984 policy statement (“Development of Water Quality-Based Permit Limitations for Toxic Pollutants: National Policy,” 49 Federal Register 9016 [March 9, 1984]) and draft Technical Support Document (“TSD”) were “rules” requiring notice and comment under the Administrative Procedure Act, 5 USC 553. The Court noted that informal rulemaking regarding 40 CFR 125.3(c)(4), which was pending between 1980 and 1984, did not limit Agency information gathering to the issuance of new or revised notices of proposed rulemaking, and the two documents did not have independent legal value. (In other words, the EPA national policy and the TSD were not binding norms but general statements of policy/guidance.) Industry also challenged EPA’s refusal to provide an affirmative upset defense to noncompliance with water quality-based limits. The Court indicated that the CWA does not expressly allow such an upset defense, and, upon considering the Act’s structure and legislative history, it could discern no congressional intent to provide for the defense in water quality permitting. Significantly, in reaching this position, the Court relied heavily upon the language and legislative history of CWA Section 301(b)(1)(C), by which Congress clearly did not relate compliance with water quality-based limitations to the capabilities of technology. In the Court’s view, “Congress had a deep respect for the sanctity of water quality standards and a firm conviction of the need for technology-forcing measures.” 895 F.2d at 208-09. However, the Court concluded that EPA had acted arbitrarily in dismissing the defense as impracticable, and directed EPAto conduct further proceedings on the issue.

l Finally, the Court rejected challenges to EPA’s regulations governing State public participation requirements and penalty levels. In deciding these issues, the Court noted Congressional desire for nationally uniform effluent limitations as reflected in the legislative history of the 1972 CWA. The Court stated : Uniformity is indeed a recurrent theme in the Act, a direct manifestation of concern that the permit program be standardized to avoid the “industrial equivalent of forum shopping” and the creation of “pollution havens” by migration of dischargers to areas having lower pollution standards (859 F.2d at 174 [footnotes omitted] and see accompanying footnotes 17-20 citing various provisions of the legislative history of the 1972 CWA).

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# APPENDIX 

# C

AMBIENT TOXICITY TESTING AND DATA ANALYSIS

### Ambient Toxicity Analysis
Ambienttoxicity testing proceduresareusefulwhere measurementoftoxicity levelsafterdischarge isimportant in the assessment of toxic effluent impact. Thisisparticularly true where impact iscausedbythe presenceof multiple point sources.The purposeof this testing isto provide an analysisof toxicity levelsinstreamfrom whateversourcesoftoxicity areaffectingthe receivingwater.

Procedures
Thebasicambienttoxicity testing procedureisto exposetestorganismsto receivingwatersamplestakenfrom selectedsampling stations above, at, and below the discharge point(s). Sinceeffluent concentrations after discharge areoften relatively low, chronic toxicity testsshould be conducted sothat the testsare sensitive enoughforthepurpose. The methodsavailablefor chronic testing of sufficiently short duration are limited. Two organismsfor which short-termchronictoxicity testsareavailablearePimephales promelas andCeriodaphniasp. Thefollowing proceduresareused:

•

•
•

•

• Select instream sampling stations based on the mixing characteristics involved in the specific dischargesituation. Collectadaily grabsampleoradailycompositesampleof receivingwaterfromeachstation. Usearenewaltesting methodto exposetestorganismstothe daily samplescollectedateachstation. Useanappropriatenumberof replicates(10for Ceriodaphnia)foreachsamplingstation. Nodilution seriesisrequiredwherescreeningisthe primarygoal. Conducttesting atalow-flow period, although it isnot necessary to conduct the testsatthe critical low-flow period. Testingisbestwhen relativelystableflow occursduring the testperiod. Recordthe resultsofthetesting intheformat showninTableC-1. Thesurvivalofthe testorganisms andthe effecton their growth or reproduction areusedasendpoints. FigureC-l plotsthe resultsin graphicformsothatthe patternofambienttoxicity canbeobserved.

C-l

### Table C-l. Young Production and Percent Survival of Cerioduphniu in Ambient Toxicity Tests at Ottawa River, Lima, Ohio

River Young Final Dailv Survival Station Station Description Mile Female SD Survival 1 2 3 4 5 6 7

1 Above Lima 46.0 15.5 8.0 90 100 100 100 90 90 90 90 2 Above STP 37.7 14.1 2.1 0 100 100 100 100 90 10 0 ; 3 Below STP 37.4 0 - 0 100 100 10 0 0 0 0 3A Midway between STPand refinery 37.3 0 - 0 100 100 10 0 0 0 0 36 Above refinery 37.1 0.4 - 0 90 90 40 0 0 0 0
4 Above chemical plant 36.9 7.5 3.6 10 4A Below chemical plant 36.3 11.1 4.6 30 100 100 100 100 100 50 10 I 100 100 100 100 100 40 30 5 Shawnee Bridge 36.4 5.7 4.0 0 9090909090600~ 6 Route 117 32.5 12.6 

### 3.8 10 100 100 100 100 100 100 10 

# i 8’ Allentown 28.8 16.8 6.1 100 100 100 100 100 100 100 100 1 Rimer 16.0 17.4 9.5 100 90909090 908080 BA “Boonie” Station 8.0 25.0 3.3 100 100 100 100 100 100 100 100 9 Kalida 1.0 25.6 5.5 100 100 100 100 100 100 100 100

I - I I I t 60 65 45 32 16 0 River Kilometers


### Figure C-l. Cerioduphniu Young Production in Water from Various Stream Stations on the Ottawa River, Lima, Ohio

c-2

# SelectingSamplingStations

The selection of sampling stations is determined by the characteristics of the site. When determining stations, consider the following factors:

l Mixing and flow-The mixing characteristics of the discharge site are useful to determine the placement of sampling stations. Knowledge of concentration isopleths allows the regulatory authority to place stations at locations instream that correspond to concentrations measured in the dilution series in the effluent tests. For example, where effluent testing shows the effluent no observed effect concentration is 10 percent, an instream station should be placed where dilution is estimated to create a lo-percent instream waste concentration. In this way, the size of a toxic plume can be measured. Sampling stations should be placed where the effluents exist at relatively constant and relatively specific concentrations. Test at specific low-flow conditions, if possible. Presence of tributaries or other sources of dilution will influence positions and numbers of stations. Where smaller tributaries have several point sources on them, treat the tributary as a point source. Obvious nonpoint source areas also should be used to set stations.

l Existing biological data-Where biosurvey data are available, sampling station location should be influenced by the more obvious trends in impact. In particular, control stations and recovery stations can be determined by biosurvey data.

. Single point sources-Single point source situations should be bracketed with an above station, an immediate mixing station, several intermediate stations corresponding to different instream concentrations, and a recovery station. Of course, a control station should be established.

l Presence of other point sources-Multiple point source situations require the ptacement of more stations between discharge points. Each source should be bracketed by sampling stations.

There are four areas or zones that can be recognized when establishing the sampling stations for ambient toxicity testing:

Zone l-An upstream zone before the effluent enters Zone 2-A zone of mixing Zone 3-A zone after mixing and before additional dilution water enters Zone 4-A zone where additional dilution occurs either from effluents or tributaries.

All possible combinations of occurrences are not practical to discuss but must be sorted out for each site. Some generalizations are important to mention:

l Any upstream sources of contaminants, such as other discharges, will confound the individual effects of a downstream discharge. For example, Zone 3 of the downstream discharge may occur in Zone 4 of an upstream discharge. This does not invalidate the measurement of ambient toxicity. It only makes it difficult to attribute amounts of response to each individual discharge. Response to the instream mixture iswhat ismeasured.

l Careful location of sampling stations in Zone 3 is critical. Zone 3 is the only place where toxicity decay rates of any one discharger can be measured and then only if there are no upstream discharges, or if there are, only if that upstream effluent is stable in that reach.

l In Zone 4, not only is degradation of the effluent toxicity occurring, but there is dilution of it by other effluents and tributaries. Depending on the site circumstances, one may not be able to learn anything about the ambient toxicity characteristics of the effluent of concern in this zone.

l To emphasize, what can be measured in each zone depends on the above considerations. In the more complex situation, only an estimate of ambient toxicity at each station can be obtained. No information about one effluent’s toxicity decay rate will be available where several toxic effluents mix. In the most simple situation of one discharge and no dilution downstream for a long distance, Zone 3 will be large enough to get a good measure of toxicity decay.

c-3