5 Colo. Code Regs. § 1002-31.25
The provisions of sections 25-8-202(1)(b), (2) and (7); and 25-8-204; C.R.S., provide the specific statutory authority for adoption of the attached regulatory amendments. The Commission also adopted, in compliance with section 24-4-103(4) C.R.S., the following statement of basis and purpose.
The Commission has adopted substantial revisions to the statewide standards for organic pollutants contained in section 3.1.11 . The additional standards for organic pollutants, now contained in Tables A, B and C, are based on EPA water quality criteria documents, maximum contaminant levels (MCLs), EPA drinking water health advisories, and EPA Integrated Risk Information System (IRIS) data, which have become available subsequent to the adoption of the original table in 1979. These standards are being adopted in part in response to new requirements in the 1987 amendments to the federal Clean Water Act (CWA) to adopt water quality standards for toxic pollutants, "the discharge or presence of which in the affected waters could reasonably be expected to interfere with" classified beneficial uses. CWA, section 303(c)(2)(B). Although toxic organic pollutants generally are not a major problem in Colorado surface waters at present, the Commission believes that the best policy option is to adopt numerical standards now, to help assure that these pollutants do not become a problem.
The organic chemicals for which standards are being adopted generally are not naturally occurring water quality constituents. Therefore, the Commission has determined that a statewide approach to adoption of water quality standards for these substances is the most efficient and appropriate means of assuring human health and environmental protection in a timely manner. Where there may be naturally occurring levels of some specific pollutants for which standards are adopted, or where other site-specific factors warrant, the Commission has preserved the flexibility to adopt alternative, site-specific standards, as discussed further below. Considering the federal requirements and the potentially serious adverse impacts from these toxic pollutants, the Commission has determined that the record in this proceeding demonstrates the need for the adoption of these standards.
Recently adopted legislation-Senate Bill 181 in the 1989 session-includes new provisions that apply when the Commission adopts "rules more stringent than corresponding enforceable federal requirements." Section 25-8-202(8)(a), C.R.S. The Commission interprets these provisions to be inapplicable to this rulemaking, since there are no "corresponding enforceable federal requirements" that establish ambient surface water quality standards in Colorado. Section 303 (c)(2)(B) of the 1987 amendments to the federal Clean Water Act includes a directive that, whenever states revise surface water quality standards, they adopt standards for certain toxic pollutants. However, no federal standards-no enforceable federal requirements-are established for these pollutants. EPA develops water quality criteria, but these are not enforceable standards. Enforceable requirements exist only after states have adopted standards. EPA can adopt standards for a state that fails to act, but this has never occurred in Colorado.
Moreover, even if this section did apply, the Commission finds that the standards adopted are based on sound scientific and technical evidence in the record. This basis is demonstrated in part by the testimony submitted by witnesses for the Division and for EDF, including the underlying analyses and studies referenced therein. The Commission's evaluation of the available information, and its assessment of how this information should be reflected in the standards, is also addressed in the discussion of "Basis for Specific Standards" set forth below. Finally, these standards are necessary to protect the public health, beneficial uses of water, and the environment of the State-in part due to the fact that there are no corresponding enforceable federal requirements. As mentioned above, the Commission believes that the best policy to assure protection of these uses is to adopt uniform, preventive standards. Without such standards in place, waters that have not yet been affected by the discharge or presence of such toxic pollutants may be adversely affected in the future, and protection of their present and future uses would then not be assured. The approach adopted by the Commission attempts to assure protection of uses by initially applying the standards broadly, but at the same time assures economic reasonableness by providing flexibility to revise the standards on a site-specific basis and to take site-specific circumstances into account in determining the need to apply the standards in regulating individual entities. See, e.g., the discussion below regarding "Integration into Discharge Permits".
Section 3.1.11 also has been revised by deleting several previous references to ground water. Concurrently with these amendments to this regulation, the Commission is adopting similar new provisions in the Basic Standards for Ground Water, 3.11.0 (5 CCR 1002-8). No changes are being made at this time to the radioactive materials standards contained in section 3.1.11 , although new language is being added clarifying that alternative site-specific standards may be adopted by the Commission.
Finally, certain corresponding and clarifying changes have been adopted in section 3.1.14 , regarding integration into discharge permits.
The previous basic standards for organic pollutants in section 3.1.11 applied to all state surface waters, irrespective of site-specific use classifications. The original proposal for this hearing set forth a similar approach for the new standards. After considering the various alternative proposals, the Commission has decided to tie applicability of the new organics standards to established classifications for aquatic life and water supply. Because comprehensive classification of the surface waters of the state has already occurred, this approach should assure protection of appropriate uses.
A wide range of approaches to setting standards for the organic pollutants were considered during the course of this proceeding. These ranged from setting "zero" standards for some pollutants (carcinogens), to setting standards only for chemicals for which MCLs have been adopted, to setting standards based on practical quantitation limits (PQLs).
The standards adopted have been established as interim rather than permanent standards for two general reasons. First, it is clear to the Commission that the development of appropriate numerical criteria to protect various beneficial uses from organic pollutant impacts is a rapidly evolving area that is still very much in flux. For example, there are currently significant differences among the various criteria, advisories, and maximum contaminant levels available for a number of specific pollutants. As new information becomes available and potential conflicts among the various numerical levels are resolved, it may be appropriate in specific instances in the future to adopt permanent standards either more or less stringent than the interim standards being established at this time. However, given the importance of controlling toxic pollutants in the environment, the Commission believes that it is necessary to move forward with the adoption of interim statewide standards at this time, and that the interim standards adopted are reasonable based on the best currently available information.
Second, there is currently substantial uncertainty and concern regarding whether or how a federal antibacksliding policy may apply to any standards adopted at this time. The Commission believes that it is not appropriate for antibacksliding or downgrading restrictions to apply to any subsequent, more lenient, revisions of these standards based on improved general or site-specific information. The fact that these restrictions would not apply to such subsequent revisions is a material assumption upon which the Commission is relying in adopting these statewide standards.
In addition to these two general motivations for adopting interim standards, the Commission wishes to even more strongly highlight the "interim" nature of the standards being adopted for aquatic life classifications. For standards applied to waters with aquatic life classifications (Table C), the Commission has adopted water quality standards based on toxicity to aquatic life from EPA's "Gold Book." The principal alternative, which the Commission has chosen not to adopt at this time, would be standards based on "fish ingestion" criteria, which are intended to protect the public from potential adverse health impacts of eating contaminated fish. As a matter of public policy, it is extremely important that fish caught in Colorado streams be safe for the public to eat. However, pending further review of this issue, the Commission believes that adoption of statewide numerical standards based on fish ingestion criteria would be premature at this time.
Therefore, pending further investigation as described below, it cannot be stated that the pollutants in question would "reasonably be expected to interfere with" fish ingestion "uses" on a statewide basis. Rather, the need for such standards can and will be addressed on a site-specific basis where appropriate. Given the established system of site-specific surface water classifications and standards, this can be accomplished practically in the triennial review process for individual river basins. Should a specific situation arise where there was immediate concern regarding such pollutants and fish ingestion, the Health Department would issue appropriate health advisories and work with the Division of Wildlife to insure the area was properly posted. In addition, the desirability of statewide standards can be reassessed over time.
It is the Commission's understanding that the health based 304(a) criteria adopted by EPA are based on regular ingestion of fish by humans over a 70 year lifetime. It is unlikely that these circumstances exist on a statewide basis in Colorado and hence the Commission determined that application of the 304(a) fish ingestion criteria are not appropriate at this time.
The Commission is requesting that the Division staff further analyze this issue for subsequent reassessment on a statewide or site-specific basis. For example, further analysis should be given to the applicability of the assumptions underlying EPA's fish ingestion criteria to the circumstances in Colorado. Are general or site-specific levels of fish consumption in Colorado consistent with EPA assumptions? Should statewide or site-specific standards that apply modified assumptions be considered? To what extent do heavily-fished streams overlap with those already classified for water supply, resulting in the presence of more restrictive, health-protective standards even without application of the fish ingestion criteria? Do bioconcentration factors require more stringent standards than those to protect water supply? Are certain organic chemicals more of a concern than others with respect to potential impacts in Colorado?
Along with these types of Health Department efforts to examine circumstances unique to Colorado, the Commission anticipates that additional national information regarding fish ingestion criteria for organic pollutants will be developed over the next several years. Taking all such information into account, the Commission intends that the Division staff should raise any possible need for revising the current interim aquatic life standards in subsequent triennial reviews of this regulation, or of site-specific classifications and standards, as it determines appropriate.
In addition to pure public health concerns, Colorado has a strong economic motivation to assure public confidence in the safety of consuming fish from Colorado streams, to protect the recreational fishing industry. If at any point it becomes clear that a real risk to public health could develop, or that the remaining uncertainties make preventive standards the preferable public health policy option, more stringent statewide or site-specific standards may be adopted in the future.
On Table C, several chemical compound families are identified. The Division and Commission considered several options regarding whether or how to set standards for these families, in part because a detection method has not been established for families per se. The detection method for families is essentially the detection of individual compounds within the family. The sum of the concentrations of the individual compounds establishes the family's concentration level. This method is quite cumbersome in many cases. For instance, Polynuclear Aromatic Hydrocarbons are comprised of hundreds of different compounds. At this time, the Commission believes it is more appropriate to not set a standard for an entire family, but rather to set standards for individual compounds within certain families as listed in the EPA Gold Book. The Commission realizes that there are many toxic compounds which are addressed in the Gold Book only as families. However, due to the complexity of the problem, the Commission will defer these to possible additions in updates of this regulation during the triennial review process, as more specific criteria are developed or other options are identified to address this issue.
The organic pollutant standards for waters classified for water supply protection have been divided into two categories-Table A for carcinogens and Table B for non-carcinogens. For non-carcinogens, the interim standards are based on MCLs, or lifetime exposure levels derived from the "reference dose" for constituents for which no MCLs have been adopted. Non-MCL standards generally are based on EPA drinking water health advisories or IRIS data. The Commission has determined that this is the best information currently available to derive appropriate criteria for protection of human health from non-carcinogens.
For the Table A carcinogens, the interim standards are again based on MCLs for constituents for which these limits have been developed. For non-MCLs, standards based on the 1x10-6 cancer risk level have been adopted. Recognizing that there is no scientifically "correct" risk level, the Commission has selected this level as a matter of policy, because it believes this is an appropriately conservative and protective level for human health risks.
To determine which specific pollutants to list on Table A, any particular compound was considered to be carcinogenic if it has been classified by EPA as either a Group A (known human carcinogen) or Group B (probable human carcinogen) compound. Compounds classified as Group C (possible human carcinogen), Group D (information inadequate to assess), or Group E (not anticipated to be a carcinogen), were treated as non-carcinogenic and listed on Table B. A few specific compounds classified by EPA as Group B/C were considered carcinogens and included in Table A.
Section 3.1.11 clarifies the Commission's ability to adopt site-specific standards to apply in lieu of the statewide standards where appropriate. One such example where this might be appropriate was mentioned above-i.e., where a more restrictive aquatic life standard may be appropriate because adverse human health impacts from fish consumption are demonstrated to be a potential problem on a site-specific basis. Rather than attempt to anticipate all potential factual justifications for different site-specific standards, the Commission has determined that it is most appropriate simply to refer to the standard statutory and regulatory criteria for such determinations.
The Commission believes that because these standards are being adopted without taking site-specific factual circumstances into account, any revised site-specific standards based on such a site-specific analysis should not be considered a downgrading. Rather, this would simply be a determination that different numerical standards are adequate to protect the uses in question. The fact that downgrading criteria would not apply to such circumstances is another material assumption upon which the Commission relies in adopting these statewide standards. Of course, any proposal to remove an existing use classification in a site-specific hearing would be subject to the downgrading criteria.
The Commission also has added four new subsections to section 3.1.14 . New subsection (9) explains how detection levels are to be used in implementing the new standards, in view of the fact that in many instances the standards are lower (more stringent) than common detection levels. Although the new standards will be used in appropriate circumstances to calculate effluent limitations for discharge permits, the Commission believes that it is appropriate to recognize the limits of current detection technology by clarifying that specified detection levels will be used for purposes of determining permit compliance.
The specific detection levels to be used for these statewide standards are being specified in the regulation. Although this is not the Commission's normal practice, it has determined that this step is appropriate in this instance because the need to comply with very stringent standards for organic pollutants will be new to many regulated entities.
The Commission has decided to rely for now on detection levels based on practical quantitation limits (PQLs) associated with GC-MS laboratory analysis techniques, except where only a GC-based PQL exists. For those compounds which have an MCL as the standard, the corresponding detection method was adopted. The Commission has decided not to require detection to the generally more stringent GC-PQLs in all circumstances, in order to temper the economic impact of this new set of standards. Of course, as scientific knowledge and technology advance, this decision may be reconsidered in subsequent rulemaking hearings. In a few specific instances where national guidance is not available, PQLs have been established based on the Health Department Laboratory's best professional judgment.
One major concern raised by several parties to the hearing concerns the potential application of antibacksliding restrictions to discharge permit requirements resulting from these new statewide standards, should more lenient statewide or site-specific standards be adopted in the future. One of the material assumptions relied on by the Commission in proceeding with the adoption of these standards at this time is that antibacksliding should logically apply to discharge levels actually attained, rather than to more stringent underlying standards or effluent limitations. In other words, the fact that a discharger is achieving a PQL-based compliance threshold for an effluent limitation based on one of the statewide organic standards does not necessarily mean that the more stringent effluent limitation level itself is being attained.
The remaining new subsections of section 3.1.14 provide guidance as to when a specific discharge permit may need effluent limitations or monitoring requirements based on one or more of the organic pollutant standards. The Commission obviously does not intend that all discharge permits will contain effluent limits for all of these constituents. Subsections 3.1.14 establish general criteria to be followed by the Division in determining when such limits are necessary. These criteria are intended to assure that effluent limits are imposed only for those pollutants that can reasonably be expected to occur in a discharge at levels such that the applicable standards would be threatened or exceeded. The Division's determination could be based, for example, on effluent monitoring results from a particular discharger, or on knowledge that a particular chemical is used in a specific industry's process and may be present in its wastewater at levels which, following discharge, could be inconsistent with water quality standards. Correspondingly, the language in the regulation clarifies that if monitoring data for all probable sources identified demonstrates that a particular chemical is not present at levels of concern, no effluent limitation should be established. The Commission cannot realistically anticipate all factual circumstances that could arise, but rather recognizes that the Division will need to exercise its professional judgment, based on the best information available to it, in making such determinations.
Concern was expressed during the rulemaking process that situations could arise where municipal dischargers violate effluent limitations based on the new organics standards, but where the source of such pollution is difficult or impossible to control through traditional pretreatment programs. For example, it was suggested that if the source of a problem turns out to be widespread use of certain household products, the only practical solution may be a product ban, which cannot feasibly be accomplished by the municipality. Given the uncertainty at present regarding the nature and extent of any such problems that could be identified, it would be premature for the Commission to attempt to specify a particular remedy for such situations in advance. However, the Commission is committed, should such circumstances develop, to taking any actions within its authority to assure that responsibility for and resolution of such problems is addressed in a practical manner. For example, it has been suggested that the Commission could hold a hearing to investigate the source of the problem, and then report its conclusions and recommendations to the Governor and the General Assembly. Finally, the Commission notes that the Division has authority to exercise its enforcement discretion in individual situations in a manner that it determines to be appropriate based on the facts at hand.
New subsection 3.1.14 addresses monitoring requirements for pollutants covered by the new organic chemical standards. This subsection is intended to help assure that monitoring requirements for discharges of such pollutants are reasonably related to the potential for the presence of such pollutants in the discharge at levels inconsistent with water quality standards, and that such requirements are imposed to the maximum extent practical on those responsible for the presence of the pollutants. For example, if a specific industrial facility is the only source of a particular pollutant, monitoring of that facility's discharge into a domestic facility's collection system could be substituted for monitoring of the domestic discharger's effluent.
Finally, a general goal of new subsections 3.1.14 is to help assure that the new standards are implemented in a manner that is consistent with the state's pretreatment program. The Commission's intent is to avoid unnecessary, duplicative requirements to the maximum extent practical.
One concept which was raised during the rulemaking process that has been rejected by the Commission was the possibility of adding new "point of compliance" language into this portion of the regulation regarding integration into discharge permits. The Commission believes that this is not necessary at this time and would add potential confusion since "mixing zone" provisions-a related concept-are already addressed elsewhere in this regulation. The Commission's simultaneous adoption of new organics and radioactive materials standards for ground waters in the Basic Standards for Ground Water, 3.11.0, may add a new factual determination that will need to be made in drafting some surface water discharge permits-i.e. What effluent limitations are needed, if any, to assure compliance with ground water standards at their applicable point of compliance, if recharge from the surface water in question is likely? However, this determination does not require additional regulatory provisions in this document.
Concerns were raised during the hearing process regarding the relationship of these new statewide organic pollutant standards to environmental standards that might be established under federally-dictated environmental programs. The Commission does not intend to attempt to preempt such programs by the adoption of these standards. To address the one specific program where there appeared to be a potential for conflict in the surface water context, the Commission has added new subsection 3.1.11 , relating to the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA).
The Commission also notes that, in accordance with Senate Bill 181, for certain categories of activities these standards will be implemented initially by other state "implementing agencies," except for use in discharge permits. Section 25-8-202(7), C.R.S. The Commission believes that this system should be efficient and effective. Moreover, if at any time it appears that the other agencies are not taking adequate steps to assure compliance with the standards, the Commission is authorized by SB181 to step back in and take appropriate action.
The new statewide standards for organic pollutants could have an adverse fiscal impact on any persons discharging such pollutants to state waters. It is impossible to quantify that impact at this time. Such impacts will depend to a large degree on the nature and extent of any of the listed contaminants in dischargers' waste streams. The marginal impact of these amendments also is difficult to quantify since the existing narrative "free from toxics" standards has already been used to establish effluent limitations for organics for some dischargers. In addition, the recently adopted biomonitoring requirements will already require efforts to remove toxics from effluent. Any fiscal impact on nonpoint sources would depend on the nature of any control regulations that the Commission may adopt in the future. However, the Commission believes that in general the cost associated with compliance with the standards will be counter-balanced by the environmental benefits associated with protecting beneficial uses, although these benefits are also impossible to quantify at this time.
The Commission has incorporated several elements into these amendments in an effort to make them as economically reasonable as possible, consistent with providing adequate protection of human health and the environment. Examples of these elements include:
Each of these elements is discussed in more detail above, in earlier sections of this statement.
PARTIES TO THE PROCEEDINGS OF THE PUBLIC RULEMAKING HEARING FOR THE BASIC STANDARDS FOR SURFACE WATER
5 CCR 1002-31.25