Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-42 - REGULATION NO. 42 - SITE-SPECIFIC WATER QUALITY CLASSIFICATIONS AND STANDARDS FOR GROUND WATER
Section 5 CCR 1002-42.10 - Statement of Basis, Specific Statutory Authority, and Purpose (1991 Rocky Flats Hearing)

Current through Register Vol. 47, No. 5, March 10, 2024

The provisions of C.R.S. 25-8-202(1)(a), (b) and (2) and 25-8-203; and 25-8-204 provide the specific statutory authority for adoption of these regulatory provisions. The Commission has also adopted, in compliance with C.R.S. 24-4-103(4), the following statement of basis and purpose.

BASIS AND PURPOSE:

EG&G and DOE jointly raised 2 issues which questioned the Commission's jurisdictional authority to promulgate the ground water standards and classifications in this proceeding. These parties argues that the Commission has no authority to regulate the Rocky Rats facility as there has been no waiver of sovereign immunity for the application of ground water standards and classifications at federal facilities. EG&G and DOE asserted that the waiver of sovereign immunity found in the federal Clean Water Act did not provide dear and unambiguous authority for states to regulate ground water at federal facilities because the provisions of the Act were not intended to apply to ground water. Secondly, EG&G and DOE argued that the Commission has no authority to regulate the discharge of radionuclides in particular plutonium, as the Atomic Energy Act preempts such regulation.

Briefs were submitted on these issues by interested parties, and, after careful consideration, the Commission has determined that it has jurisdiction to promulgate the regulation pursuant to its authority under the Colorado Water Quality Control Act The Commission's decision is based, in part, on the knowledge that standards and classifications are not self-implementing, but are used as appropriate, by the Division and other agencies through their own water pollution control programs. The promulgation of standards and classifications alone does nor confer any authority to regulate any particular discharger, and it is not the Commission's intention to attempt through this rulemaking to override any preemption of the Atomic Energy Act This decision is consistent with the Commission's promulgation in 1990 of surface water quality standards and classifications for Walnut Creek and Woman Creek.

Classifications

The basis for classifying specific ground waters of the state is set forth in the Basic Standards for Ground Water Section 3.11.10 . Classification of the ground waters at the Rocky Flats site was requested by the City of Westminster. The intent of this classification is to protect specified ground water from uncontrolled degradation and thereby protect existing and future uses of that water.

The classifications of Domestic Use-Quality and Surface Water Quality Protection are appropriate for the Rocky Flats alluvium and Quaternary deposits which discharge into classified surface water segments. Classified segments of Walnut and Woman Creeks contribute to drinking water for 180,000 residents of Broomfield, Westminster, Thornton and Northglenn through Great Western Reservoir and Standley Lake. These segments also have Recreational Class 2, Aquatic Life Class 2 and Agricultural classifications through the "Classifications and Numeric Standards South Platte River Basin, Laramie River Basin, Republican River Basin, Smoky Hill River Basin" 3.8.0.

Numerical Standards

The water quality standards in Tables 1-4 of the Basic Standards for Ground Water are appropriately assigned to all aquifers in the specified area because these standards are set to fully protect the classified uses and because ambient quality is generally better than these standards. It is not necessary to establish standards for pollutants not currently found in the list of statewide standards for organic chemicals since current information indicates that techniques for remediation of the site to the level of established standards will also reduce those contaminants without standards to acceptable levels.

It is appropriate to apply the surface water quality standards for Woman Creek and portions of Walnut Creek (Segment 4, Big Dry Creek) to the shallow aquifers at Rocky Flats because they contribute water to those streams which the Commission recently protected with more stringent standards.

The Commission has decided not to set standards equal to background levels at this hearing. The characterization of background in the vicinity of the Rocky Flats Plant is an ongoing process, and the Commission believes that the agencies charged with implementing the remedial action at the plant under RCRA and CERLA - the Colorado Hazardous Materials and Waste Management Division and the United States Environmental Protection Agency - may have an opportunity to determine background levels as part of the overall remedial action at Rocky Flats. The implementing agencies may also have authority to set compliance standards on constituent-specific basis for constituents where background levels exceed the standards, or the Commission may set standards at background when sufficient evidence is available to it.

Similarly, if the Water Quality Control Division has regulatory jurisdiction over an activity at the Rocky Flats Plant, the Division may consider background levels when enforcing permit conditions, if consistent with Division enforcement authority and policy then in effect.

Plutonium Standard

There was considerable debate in this hearing regarding the appropriate basis for and numerical level of a plutonium standard for ground water in the vicinity of Rocky Flats. A standard of 0.05 picocuries per liter has been adopted, based on the existing surface water standard for Walnut and Woman Creeks. This surface water standard was based on existing ambient levels of plutonium measured in these two streams, and therefore serves as a nondegradation standard that should prevent any increase in contamination. The site-specific plutonium ground water standard now adopted supercedes the statewide standard of 15 picocuries per liter, for ground water within this specified area.

It was also argued in this hearing that the Commission should adopt a health-based standard for plutonium, and that the appropriate health-based level is lower than 0.05 picocuries per liter. Based on the evidence submitted, the Commission has determined that it would be premature to set a different, health-based standard for plutonium at this time. Although some preliminary analysis has been done based on a 1 X 10-6 risk level, further internal and external peer review of the preliminary calculations needs to occur in order to determine an appropriate long-term, health-based standard.

Because the Basis Standards for Ground Water provide, at section 3.11.7 E, that the Commission will not consider changes in ground water standards more than once in any twelve month period, the Commission plans to hold a new rulemaking to reassess an appropriate plutonium standard in February, 1992. The Commission anticipates that the hearing will address radionuclide standards generally, for surface water and ground water, statewide and in the vicinity of Rocky Flats.

Specified Area

The specified area adopted by the Commission generally tracks the boundaries of the federal reservation on which the Rocky Flats Plant is located. All of the parties to this hearing indicated that they agreed with or were not opposed to this specified area.

Points of Compliance

The Commission has decided not to set any points of compliance for the water quality classifications and standards being adopted in this proceeding. A point of compliance would be established by whatever agency or agencies may have regulatory authority to implement these classifications and standards in the future. The Commission is not attempting in this proceeding to prejudge or second guess what agency or agencies that may be. If these classifications and standards are implemented by the Water Quality Control Division in accordance with its authority, points of compliance shall be established in accordance with its authority. In such circumstances, the Commission believes that points of compliance developed by the Division should at a minimum assure compliance with surface water classifications and standards established for the affected segments.

Although it appears from the evidence that potential exists for preventing Walnut and Woman Creek water from reaching the drinking water supplies in Standley Reservoir and Great Western Reservoir, the Commission's preceding direction to the Division concerning ground water points of compliance is currently appropriate. Until and unless the drinking water supplies are physically isolated, those reservoir should be protected by strict standards. As the Commission similarly stated in the Statement of Basis and Purpose for the surface water standards in Woman and Walnut Creek, if in the future the cities' water supplies are adequately isolated, the Commission can reconsider at that time the appropriateness of both surface and ground water classifications and standards and its direction to the Division concerning points of compliance.

PARTIES TO THE RULEMAKING HEARING FEBRUARY 4, 1991