5 Colo. Code Regs. § 1002-41.13
The provisions of section 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.
Since the Commission adopted The Basic Standards for Ground Water in 1987, no specific ground water quality classifications and standards have been adopted for any state ground waters. The purpose of the adoption of the statewide standards that are the subject of this action is to provide a statewide baseline of protection by establishing standards that will apply broadly to Colorado ground waters, for certain toxic organic pollutants and radioactive materials.
As a part of the same proceeding that led to the adoption of these ground water standards, the Commission has adopted similar statewide surface water standards for organic pollutants in section 3.1.11 of the Basic Standards and Methodologies for Surface Water, and deleted certain very general statewide ground water quality standards previously contained in that document. As explained more fully in the Statement of Basis and Purpose for those changes (section 3.1.22), the Commission has adopted an expanded set of numerical basic surface water standards for toxic organic pollutants in part due to requirements of the federal Clean Water Act. Although that Act does not contain any requirements for the adoption of ground water quality standards, the Commission believes that it is appropriate in this instance to provide consistent levels of protection for both surface and ground water resources. The principal difference between the two sets of standards is the lack of aquatic life standards for ground water, because ground water quality does not affect aquatic life unless it emerges at some point and becomes surface water (which is then subject to surface water standards).
Evidence has been submitted that on a site-specific basis some ground waters have become substantially contaminated with organic pollutants, e.g. as a result of past disposal practices. Although there is no information currently indicating that such contamination is widespread, the Commission believes that the best policy option is to adopt numerical standards now, to help assure that these pollutants do not become a more widespread 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.
In addition to the adoption of the new organic pollutant standards, the Commission also adopted new ground water quality standards for a limited list of radioactive materials. These standards are identical to those which have been and will continue in place for surface waters. The Commission rejected a proposal to adopt a new numerical uranium standard for ground water at this time, because the Commission believes that this issue warrants more specific analysis prior to such action. For example, the consistency with established surface water quality standards for uranium in several basins needs to be more fully considered.
Considering the desirability of having consistent levels of protection for surface and ground waters and the potentially serious adverse impacts from these 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 ground water quality standards. 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, and the directive that states act applies only to surface water, not ground water.
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 "Point of Compliance".
Finally, in addition to the revisions discussed in more detail below, the Commission has made relatively minor changes to sections 3.11.2 and 3.11.7 for consistency with the major changes being adopted.
In contrast to the approach the Commission has taken for the new surface water organic pollutant standards, applicability of the new ground water standards is not tied to the presence of corresponding ground water use classifications. For the reasons discussed above, and because it is likely to take several years to adopt site-specific ground water classifications throughout the State, the Commission has decided as a matter of policy that these standards now being adopted should apply statewide on an immediate basis.
During the course of the proceeding, other alternatives were considered. For example, one option discussed was applying the standards to (1) all nontributary ground water, (2) all tributary ground water that has been classified "domestic use-quality", (3) all tributary ground water located in aquifers that have been or are being used for domestic water supply purposes, and (4) all ground water that is tributary to streams or stream segments which are classified for domestic water supply. Alternatives such as this have the disadvantage of requiring potentially difficult factual determinations regarding precisely where the standards apply. While such issues could be resolved by the Division as they arise, this system would make it difficult for the public to know in advance where the standards apply.
The intent of such alternatives was to avoid unnecessarily stringent requirements that could result from applying the standards to ground water that does not warrant protection as an actual or potential drinking water supply. However, the Commission believes that this goal can be achieved by a simpler approach. Pursuant to recently adopted legislation (SB181), other state regulatory agencies with ground water quality protection responsibilities have the flexibility to determine appropriate points of compliance when implementing these standards. (See section 3.11.6 and the discussion under G., below.) Second, the Commission has included language in section 3.11.5 to clarify that certain federal program regulatory determinations regarding ground water quality would not be superceded by the Commission's standards, where such programs dictate a contrary result. (See the discussion under F., below.) Finally, the Commission has preserved the option of establishing different site-specific standards to apply in place of the statewide standards, where determined appropriate following a rulemaking hearing before the Commission. (See section 3.11.5 , and the discussion under D., below.)
The Commission believes that the combination of these provisions provides ample means of assuring that unnecessarily stringent regulation, based on the statewide standards, can be avoided.
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 maximum contaminant levels (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 principally because 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.
The organic pollutant standards 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 health advisories or integrated risk in formation system (IRIS) data. The Commission has determined that this is the best information currently available as to the appropriate criteria for protection of human health for 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 1 × 10-6 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 3.11.5 clarifies the Commission's ability to adopt site-specific standards to apply in lieu of the statewide standards where appropriate. 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 a material assumption upon which the Commission relies in adopting these statewide standards.
Section 3.11.5 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. 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 establishing performance standards.
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 Colorado Health Department Laboratory's best professional judgment.
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 programs where there appeared to be a potential for conflict, the Commission has added new subsection 3.11.5 , relating to the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), and Resource Conservation and Recovery Act (RCRA) Subtitle C and I programs. This section clarifies the Commission's intent that both a compliance level or performance standard, and a point of compliance that differ from those established in this regulation or in a site-specific hearing by the Commission can be utilized by the relevant agencies where authorized by those programs.
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." 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 Commission has added significant new provisions to section 3.11.6 , regarding points of compliance. In subsection (A) the Commission has now noted the integral relationship between numerical standards and points of compliance. In subsection (B), the Commission has specified points of compliance to apply for the new statewide organic pollutant and radioactive materials standards, unless a different site-specific point of compliance is later adopted by the Commission, or applied by another agency pursuant to its independent authorities.
For situations where significant ground water quality contamination has not yet occurred, the Commission believes that the downgradient limit of the area above which potentially polluting activities are located- the edge of the disturbed area-is a reasonable and environmentally protective point of compliance. However, for situations where contamination exists as of the effective date of these regulatory amendments, the Commission recognizes that it may not always be feasible to clean-up the ground water to the levels established by these statewide standards back to the edge of the disturbed area. Therefore, the alternative potential points of compliance listed in section 3.11.6 have been established for such situations. This approach is being adopted to help assure the administrative practicality of applying the new statewide standards, to reduce the administrative burden of potentially numerous site-specific rulemaking hearings before the Commission, and the potential resulting delays in remediation of contaminated sites.
It was suggested during the course of the proceeding that subsection 3.11.6 should make a further distinction between facilities at which control requirements have been established as of the effective date of these amendments, and facilities at which such requirements have not been established as of that date. The Commission has rejected this option for several reasons. First, significant factual and legal uncertainties could arise in determining which facilities are ones "at which control requirements have been established." For example, have control requirements "been established" for a hazardous waste disposal facility operating without a permit?
Second, in order to achieve a preventive program, the Commission believes that activities and facilities that pollute ground water should be put on notice now that they may some day need to comply with these standards, even if they are not currently subject to specific regulatory requirements under an existing program. Section 3.11.6 already allows an effective "grandfathering" of some pollution that has occurred prior to the effective date of these statewide standards. The Commission sees no reason to adopt a general grandfathering of future ground water pollution. If site-specific inequities would result from application of the statewide standards and points of compliance, that can be addressed in a site-specific hearing before the Commission (or, in some instances, by the implementing agency). Moreover, if new control regulations are proposed in the future, in a rulemaking proceeding to consider their adoption the Commission would consider whether application of the points of compliance established in this regulation would be appropriate in that new program. If such application would lead to unreasonable or inequitable results, the Commission could apply different provisions at the time, while still protecting the appropriate beneficial uses.
The Commission's overriding concern is that a point of compliance be established that is protective of human health and the environment. The Commission is adopting section 3.11.6 to provide further clarification of the approach that it intends to take to considering site-specific points of compliance. That section provides that when requested in a site-specific hearing, the Commission shall adopt a point of compliance closer to the existing source of contamination when the alternative points of compliance provided in section 3.11.6 are not protective of human health and the environment. Conversely, section 3.11.6 also requires the Commission, when requested in a site-specific hearing, to establish a point of compliance further from the source of contamination than the alternatives provided in section 3.11.6 considering the enumerated factors, so long as the point of compliance remains protective of human health and the environment.
By establishing the alternative points of compliance in section 3.11.6 , for facilities with ground water contamination existing as of the effective date of these amendments, the Commission does not intend to supercede any more stringent ground water quality remediation requirements that may apply under other state or federal authorities. The Commission is attempting in section 3.11.6 , as a matter of administrative necessity, to provide an initial baseline of protection, while avoiding potential unreasonably stringent results from the application of its statewide standards that are being adopted without taking site-specific conditions into account. Where a more stringent result is required or has been or is determined appropriate as a result of a site-specific analysis under another agency's program, such as RCRA or CERCLA, the Commission does not intend section 3.11.6 to preempt that result. The alternative points of compliance established in section 3.11.6 shall carry no presumptive weight in a site-specific standards hearing. In site-specific hearings, it is the Commission's intention to consistently apply the standards for establishing a point of compliance in similar circumstances at all remedial sites across the State.
Finally, the Commission has added a new subsection 3.11.6 to implement relevant portions of Senate Bill 181. In accordance with this Act, this subsection defers the initial authority to establish points of compliance to the appropriate "implementing agency." SB181 contemplates that implementing agencies will establish points of compliance for activities under their jurisdiction, in accordance with criteria established through rulemaking after public hearing and consultation with the Commission and Division, so as to protect present and future beneficial uses of water. Correspondingly, the ultimate authority of the Commission is retained to step back in and establish points of compliance if necessary to assure a consistent statewide water quality control program, in accordance with the specific provisions of SB181. The Commission intends to monitor the implementation of SB181 closely. In particular, the Commission intends to conduct an informal review of the implementation of these standards one year after their effective date. Hopefully, by that time other agencies will have had an opportunity to complete any required rulemaking and begin applying the standards where appropriate. If necessary, the Commission will at that time consider taking additional action of its own to assure that the standards are implemented in a timely and effective manner.
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 of any control regulations subsequently adopted by the Commission to implement these standards, as well as any potential future amendments to the discharge permit regulations to address discharges to ground water. The impacts will also depend on the requirements of other state agencies to implement or assure compliance with water quality standards adopted by the Commission. 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. Specifically with respect to future activities that may be subject to these standards, evidence was submitted indicating that preventing ground water contamination generally is less costly than after-the-fact clean-up or remediation.
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 GROUND WATER
5 CCR 1002-41.13