5 Colo. Code Regs. § 1002-61.32
The provisions of sections 25-8-202(1)(d) and 25-8-501 to 25-8-504, C.R.S. provide he specific statutory authority for adoption of these regulatory provisions. The Commission also adopted, in accordance with Section 24-4-103(4), C.R.S. the following Statement of Basis and Purpose.
Overview
In November, 1988, the Commission adopted Colorado's initial aquatic life biomonitoring requirements as part of the Discharge Permit System Regulations. These requirements were based upon what became known as the "diligence approach" to whole effluent toxicity (WET) control. This proved to be an unfortunate choice of words, as it came to connote a program which was dependent upon the good faith or "diligence" of the discharger in determining compliance with regulatory mandates. The regulation therefore appeared to some, including EPA, as an approach which had abandoned the concept of strict liability which is an integral part of the Clean Water Act. Though this was not the intention of the Commission, and in fact the regulation established a set of stringent requirements, the violation of which could result in immediate enforcement, the Commission has decided at this time to more clearly delineate the provisions of the State program and the Commission's intent. The Commission, nevertheless, reaffirms its belief that the original regulation constituted a lawful exercise of the State's authority to set its own water quality classifications and standards and interpret the same.
Following its initial deliberations after the June, 1991 hearing, the Commission reached a tentative decision to refine the 1988 regulation, but retain the same fundamental approach to enforcement that was set forth therein. The Commission was hopeful that establishing automatic schedules of compliance for test failures would satisfy the federal requirement that "limitations" be established to meet State-established water quality standards. However, the Commission has been advised by the Attorney General's Office that this approach would not fully satisfy the requirements of State law, which requires that a program consistent with federal statute and regulations be maintained. Therefore, the Commission has amended the original regulation in two fundamental respects. First, consistent with the requirements of Section 301(b)(1)(C) of the federal Act, which mandates the use of "limitations" to meet State-established water quality standards, including State narrative standards, the regulation provides for potential liability for individual test failures, as well as the automatic imposition of schedules of compliance where there is an exceedence of the acute toxicity limit. Thus, the enforcement process is triggered upon the failure of an acute toxicity test. A schedule of compliance will include additional testing, investigatory, and remedial requirements. Failure to comply therewith may result in a further enforcement response by the Division.
The second major change in the regulation is a direct result of the ongoing controversy between EPA headquarters and the State over permissible permit terms or conditions, with specific reference to EPA's insistence that a single acute toxicity test failure result in an enforceable violation. This dispute has led to the EPA veto of numerous State-issued discharge permits, and has raised the specter of dual permitting for Colorado's regulated community. Certain permittees have been exposed to liability under both State and federal permit requirements. In addition, its exercise of veto authority has afforded EPA the opportunity to set permit conditions independent of those addressing WET once it has acquired permit issuance authority. In order to alleviate the concerns of certain Colorado permittees over this situation, and cognizant of the fact that EPA may not find all provisions of even this amended biomonitoring regulation to be acceptable, the Commission has written into the regulation an option. Pursuant to this option, individual permittees can choose to have WET provisions placed in their permits which have previously been approved by EPA Region VIII. Thus, only one permit will be issued, and it will be a State permit. However, it will reflect only EPA's preferred toxics control language.
Though the Commission would prefer not to implement what amounts to a bifurcated regulatory system, it believes that there is no better course of action available at this time pending either final judicial review of the concepts embodied in the original Colorado biomonitoring regulation or legislative clarification. Should either such development warrant, this regulation can be reconsidered at a later date.
The Commission takes this action with great reluctance. It had hoped that the federal system would allow more flexibility in the choice of specific provisions for implementing whole effluent toxicity testing requirements. These amendments are being adopted in the hope of minimizing extended controversy and to move forward with toxicity control efforts. This regulation shall be reconsidered should the currently pending challenges to EPA's June 2, 1989, regulation published at 54 Fed. Reg. 23868, et seq., prove successful in challenging EPA's authority to impose single test pass/fail biomonitoring limitations, or if future revisions to the Clean Water Act clarify or revise the authority in this area.
Enforcement Liability
The major concern raised by EPA was that under the original regulation individual biomonitoring test "failures"--i.e. tests resulting in an exceedance of the acute toxicity limit-were not directly subject to the potential for enforcement. This concern is resolved by the provisions of new subsections 6.9.7 (a)(v). These sections now provide that a single exceedance of the acute toxicity limit may be a permit violation subject to enforcement. Specifically, permit violations may occur as a result of exceedances in a routine quarterly test or a Division-directed or conducted test.
Although the regulation now provides that single test exceedances of the acute toxicity limit may be permit violations potentially subject to the full range of enforcement and penalties, the Commission believes that this authority must be utilized with discretion. Because of the unique nature of this important new program, the Commission believes it is particularly important for the Division to give the public clear notice of its intended approach to implementation through its Biomonitoring Enforcement Guidance Document, which was submitted for informational purposes in this hearing. The Commission recommends that document not be amended without providing a public briefing to the Commission regarding proposed changes, and an opportunity for public comment to the Division.
As previously noted by the Commission at the time of its adoption of the original Colorado biomonitoring regulation, WET cannot be predicted accurately because specific chemical testing cannot predict either the biological significance of effluent constituents or possible interactions among effluent constituents. In the case of a POTW, WET may also appear as a result of non-repeated events, such as illegal dumps, or as the result of household products. As confirmed by EPA scientists, repeated test failures are often times necessary to isolate and identify the source of the toxicity. Finally, as evidenced by the written and oral testimony in the hearing record, there is still a measure of uncertainty surrounding the accuracy of a single acute toxicity test failure, and the impact of a single discharge upon the uses of the receiving stream.
In view of the above, the regulation continues to focus upon the identification and elimination of the toxicity, and departs to some limited extent from the traditional response to the exceedance of a numerical effluent limitation. The regulations provide for an automatic compliance schedule, with accelerated testing and toxicity incident response measures required within explicit and strict timeframes, whenever any violation occurs. Biomonitoring test failures that occur during implementation of activities required by a compliance schedule, including accelerated testing to determine whether the toxicity is continuing and subsequent investigatory tests to identify the toxicant, would not be permit violations. However, many of the requirements of the compliance schedule, including accelerated testing and specific toxicity response measures, are identified in the regulation. Failure by the permittee to meet the terms of the compliance schedule may result in the imposition of a penalty of up to $10,000 for each day of noncompliance. On the whole, the program provided in this regulation is no less stringent than the traditional approach, and in many ways more aggressive. It is expected that implementation of the automatic and enforceable compliance schedule will result in more rapid elimination of toxicity from point source discharges than often occurs for chemical-specific effluent violations.
When a chemical-specific effluent limitation is violated, there is an immediate target for corrective measures-i.e. the chemical for which the effluent limitation has been exceeded. When whole effluent toxicity is detected, additional investigations are necessary to determine the nature and cause of that toxicity prior to implementing corrective measures to eliminate the toxicity. Because of the need to expeditiously complete this extra step to achieve water quality control, the Commission has taken the unique step of including in the regulation specific and tight deadlines that will apply to all permittees for implementing accelerated testing and toxicity incident response efforts. For chemical-specific effluent limitation violations, the imposition of response requirements is typically handled in a case-specific compliance schedule developed in connection with a notice of violation, which is a more time-consuming process.
If a situation should arise where the Division feels that quarterly test violations in combination with compliance schedule requirements are not creating an adequate incentive for prompt resolution of a serious pollution problem, the regulation also provides the authority for the Division to direct that additional biomonitoring tests be conducted. Any exceedances occurring in these Division-directed tests would constitute additional days of violation. If necessary in an extreme situation, the Division could direct that substantial additional testing be conducted, creating the potential for substantially increased liability if a problem were not otherwise being adequately addressed. The Commission contemplates that the need for such extreme measures would be rare, and that in addressing such situations the Division would be guided by the provisions of its Biomonitoring Enforcement Guidance Document. The Commission contemplates that the need for substantial additional Division-directed tests during the period of a compliance schedule would likely arise only in instances involving severe toxicity in the effluent or actual use impairment, in combination with the failure of the permittee to expeditiously investigate and eliminate the toxicity.
Should a permittee undertake all required steps to identify and remediate the toxicity, but be unable to do so, the compliance schedule can be revised so as to avoid a needless expenditure of the permittee's resources. However, the underlying obligation to eliminate the toxicity remains, and appropriate new permit conditions may be imposed by the Division if it determines in the future that such are warranted under the facts then in evidence.
General Applicability Provisions
The introductory language in Section 6.9.7 has been revised to provide that biomonitoring requirements will be applied in individual permits when the Division makes a threshold determination that the discharge would reasonably be expected to interfere with the attainment of applicable water quality classifications or standards. This should help assure the efficiency of this program, by applying these requirements where they are most needed, and it is consistent with the requirements of Section 303(c)(2)(B) of the federal Act as amended in 1987. The Commission intends that in making this determination the Division would take into account available information regarding the nature of the discharge, site-specific classifications and standards adopted for the receiving waters, whether the discharge is to an otherwise dry streambed, applicable statewide standards, and the nature of the information acquired by biomonitoring. The record demonstrates that the biomonitoring required by Section 6.9.7 is a useful indicator of toxicity to aquatic life. No evidence was submitted demonstrating that this form of biomonitoring is a useful indicator of toxicity to other beneficial uses.
For segments not classified for aquatic life use, the Division should also consider any available information regarding why that use was not deemed attainable. If attainability is limited by nonpoint sources of pollution, or other point sources, the impact from which may be eliminated or minimized in the future, biomonitoring may be required. The Commission determined such monitoring requirements may be appropriate to assure that this permitted discharge will not cause toxicity that limits the options for overall improvement of the water quality.
As revised, subsections 6.9.7 (i) enumerate certain categories of discharges for which the biomonitoring requirements are presumptively inapplicable. These categories have been listed as a matter of efficiency since, as elaborated below, the best current information indicates that significant toxicity will not generally be expected for these types of discharges. However, the new introductory language for Section 6.9.7 gives the Division the authority to require biomonitoring information from any permittee, e.g. if there is reason to believes that the general presumption of no toxicity may not apply to a particular discharge that falls into the Section 6.9.7 (i) categories. If that information indicates that toxicity or the reasonable potential for toxicity are present, permit requirements, including the acute toxicity limit, will be imposed.
Several general permits are listed in sections 6.9.7 (i). The Division has indicated that it expects a lack of significant pollutants and toxics in "typical" effluents from such activities. Additionally, the application for certification for a specific facility is conditioned so as to require screening of the effluent and site conditions to identify nontypical conditions. If such conditions warrant, these facilities are then required to obtain individual permits. The following are additional factors that warrant a presumption of biomonitoring inapplicability for facilities covered by these general permits.
As to three other categories of industrial activities that are exempt from biomonitoring requirements, the following factors are the basis for the presumptive inapplicability of biomonitoring requirements:
The discussion in the regulation regarding the basis for the other categories of presumptive inapplicability of biomonitoring requirements should be self-explanatory.
Timing of Acute Limit Applicability
Section 6.9.7 has been revised to clarify the timing of applicability of the acute toxicity limit for different categories of dischargers. For new discharges, the limit will be incorporated into permits and become effective immediately. For discharges listed pursuant to Section 304(l)(1)(C) of the federal Clean Water Act, where biomonitoring is determined to be an appropriate component of an individual control strategy, the limit will become effective within a timeframe to allow compliance with the federal deadlines for these segments.
For other existing dischargers, the acute toxicity limit will be incorporated into permits at renewal or reopening if the Division has determined in accordance with Section 6.9.7 that biomonitoring requirements are appropriate, and become effective three years later. This timing is appropriate to allow these existing dischargers time to develop experience with this new type of monitoring and to implement any changes necessary to comply with the acute toxicity limit requirement. This is particularly appropriate since the segments affected by these dischargers were not listed under Section 304(1), and therefore were not believed to have a significant toxicity problem. Moreover, this approach is consistent with the approach being implemented by EPA Region VIII. During the first three years, should acute toxicity be identified the permittee will be required to conduct a toxicity incident response and identify a control program if possible. The control program will be expected to be implemented within a timely manner, which may be prior to the time that the limit becomes effective. In addition, if no acute toxicity is found in the effluent during such three-year period, this would be one factor taken into account by the Division in determining whether there is a continuing need for biomonitoring requirements in the permit, in accordance with Section 6.9.7 . The Commission notes that the three year period already has started to run for many dischargers who had biomonitoring requirements included in their permits under the 1988 regulations.
Relation to Numerical Standards
Questions have arisen regarding the relationship between biomonitoring requirements used to help implement a narrative water quality standard and traditional numerical water quality standards. Section 6.9.7 has been revised to clarify that numerical water quality standards are still intended to be determinative where applicable. If the acute toxicity limit is exceeded due to a substance for which a numerical standard exists, that standard will govern for assessing compliance.
The Commission has determined that this approach is appropriate as a matter of policy, to help preserve the viability of the overall, comprehensive Colorado water quality standards system. Substantial information, time and effort have gone into development of the existing acute and chronic numerical standards. At the same time, the Commission notes that exceedance of the acute toxicity limit, in spite of compliance with a numerical standard for a substance that has caused the exceedance, generally will indicate that the numerical standard in question should be reassessed. In such circumstances the numerical standard may need to be tightened to help assure protection of the classified uses, and the results of the WET testing would be taken into account in the next review of the numerical standard.
The revised regulation also provides the option for the Division to establish an interim effluent limit to control a specific substance that is determined to cause acute toxicity, but for which no numerical water quality standard exists, until the Commission can adopt such a standard.
Chronic Toxicity
With respect to chronic toxicity biomonitoring, the Commission has continued to include only testing requirements in the regulation at this time. The regulation does not establish a chronic toxicity limit. As discussed in the Statement of Basis and Purpose for the original biomonitoring provisions, legitimate questions have been raised regarding the sensitivity and reliability of the chronic test methodology. In addition, standardized toxicity characterization methods have not yet been developed for chronic toxicity.
Chronic limits were not considered appropriate for several reasons. Test variability is considered to be high and laboratory and site variables in test conditions, such as type of dilution water and food quality may influence test results and lead to excessive false positives or false negatives. Through its complex effluent toxicity testing program, EPA has claimed that the results of chronic testing of effluents is predictive of adverse ecological impacts of toxic discharges. However, this claim is being questioned in those studies where results are based on the non-lethal test endpoints of growth and reproduction. Moreover, if chronic toxicity were to be found, Toxicity Reduction Evaluation (TRE) procedures are not available for investigating the cause of chronic toxicity. Until these issues are resolved, the results of chronic tests must be used with caution and are best used to obtain supplemental information about a discharge impact to receiving waters, but not as a permit limit.
EPA regulations (40 C.F.R. Section 122.45(d)) provide that water quality standards be translated into daily maximum, weekly average, and/or monthly average permit limits, "unless impracticable." In view of the limitations on the current state of the science as described above, the Commission has determined that imposing chronic toxicity effluent limits would be impracticable at this time. This decision will be reassessed over time, as new information becomes available. In the meantime, the Commission will continue to rely principally on the extensive system of chemical-specific water quality standards that is already in place in Colorado to control chronic toxicity in point source discharges. In addition, information developed as a result of the chronic toxicity testing required by the current regulation will be taken into account where applicable in triennial reviews of water quality standards, to consider possible revisions of chemical-specific standards.
Other Revisions
Several additional provisions of the original regulation have been revised, either to respond to concerns raised by EPA or to provide additional clarification. In other instances, the Commission has determined that concerns raised by EPA did not warrant revisions in the regulation.
Use of the term "spontaneous disappearance" of toxicity was another item of concern to EPA. The EPA interpretation was that if toxicity spontaneously disappeared and the incident was closed, the exceedances also disappeared from the records. This was an erroneous interpretation, as the provision simply allows the permittee relief from continued investigation when the toxicity is no longer present. To address this concern, Section 6.9.7 has been amended to clarify that the relief is simply from further investigation.
EPA also expressed concern that the provisions in Section 6.9.7 regarding "requests for relief" could be interpreted to allow-in certain circumstances-toxicity that exceeded the acute toxicity limit to continue to be discharged, with no continuing obligation to eliminate the toxicity. The Commission has revised this section to clarify that this is not the intent. Rather, the "relief" potentially provided is with respect to further chemical and biological investigation and testing requirements. Of course, if a permittee has taken all appropriate measures that it and the Division have been able to identify and has been unable to identify and eliminate the source of the toxicity, those facts should be taken into account by the Division in proposing modifications to the permit or the compliance schedule which would avoid an unproductive expenditure of the permittee's resources.
"Cost/benefit analysis" associated with the control program, as referenced in Section 6.9.7 , was another item of concern to EPA. EPA believed that Division review of such data would be a basis for not requiring compliance with the acute WET limit. This was not the case, as the Division would still expect implementation of the control program regardless of cost. The reason for submittal of the cost/benefit analysis was to make the data available to the Commission should the matter end up before them as a use classification issue. No modification to the regulation is proposed.
The Commission adopted three revisions to the provisions regarding test methods. The previous language in the acute toxicity definition regarding acceptable levels of mortality in the control samples has been deleted. This modification is appropriate, as the provision is more suitably addressed within a technical guidance document and the adjustment may save a permittee the cost of retesting based upon excessive control mortality when all other aspects of the test appear normal.
Second, a citation to an EPA guidance document regarding short-term methods for estimating toxicity has been moved from a definition in Section 6.9.7 to the Test Methods provisions in Section 6.9.7 . Third, language has been added to Section 6.9.7 providing that the Division will advise the permittee within fifteen days if a retest is required due to unacceptable mortality in the control.
Section 6.9.7 referenced a document "Guidance for Conducting Toxicity Reduction Evaluations in Colorado". The document, however, was never developed. The regulation was therefore revised to reference the federal Technical Support Document "TSD", while retaining the option for state developed guidance which would take precedence.
Additional revision was made to the TRE portion of the regulation as follows:
PARTIES TO THE PROCEEDINGS OF THE PUBLIC RULEMAKING HEARING JUNE 3, 1991
5 CCR 1002-61.32