6 CCR 1007-3-8.54 - Basis and Purpose

These amendments to 6 CCR 1007-3, Parts 260, 264 and Part 100 are made pursuant to the authority granted to the Hazardous Waste Commission in § 25-15-302(2), C.R.S and in § 25-15-314(1), C.R.S.

Amendments to the Corrective Action Management Unit (CAMU) Rule

These amendments revise Parts 260, 264 and 100 of the Colorado Hazardous Waste Regulations (6 CCR 1007-3) to correspond to federal regulations promulgated by the Environmental Protection Agency (EPA) and published in the Federal Register on January 22, 2002 (67 FR 2962-3029).

Corrective Action Management Units, or "CAMUs," are special units created under the Resource Conservation and Recovery Act (RCRA) to facilitate treatment, storage, and disposal of hazardous wastes managed for implementing cleanup, and to remove the disincentives to cleanup that result from applying RCRA regulations for as-generated hazardous wastes to cleanup wastes. The original federal CAMU regulations were promulgated on February 16, 1993 (58 FR 8658-8685). State analogs to the federal provisions were adopted by the Hazardous Waste Commission on May 17, 1994. In adopting state analogs to the original CAMU provisions, the Commission made certain changes to the state analogs to account for certain differences in state law from federal law, to address state issues, and to express the Commission's intent in adopting the rules. Additional information regarding these changes can be found in the Statement of Basis and Purpose from the Rulemaking Hearing of May 17, 1994, which is published at § 8.10 of the Colorado Hazardous Waste Regulations (6 CCR 1007-3).

Colorado currently has authorization from EPA for corrective action, but is not authorized for the 1993 CAMU regulations. States that have authorization for corrective action but not the 1993 CAMU rule are not required to seek authorization for the CAMU amendments. This is because these states' corrective action and Land Disposal Restrictions are more stringent than the federal CAMU regulations. However, because CAMUs are an integral part of corrective action, EPA strongly encourages states to adopt the CAMU regulations.

This rule promulgates regulations that are more stringent than the existing 1993 federal CAMU regulations. Because Colorado already adopted state analogs to the federal 1993 CAMU provisions, Colorado is hereby amending its existing CAMU regulations to correspond to the new 2002 federal CAMU provisions.

The amendments being adopted at this time include:

1) Revising the definition of "Remediation waste" in § 260.10 to remove the phrase "that contain listed hazardous waste or that themselves exhibit a hazardous waste characteristic.";
2) Revising the title for Part 264 Subpart S, "Corrective Action for Solid Waste Management Units," to read "Special Provisions for Cleanup.";
3) Adding Section 264.550 "Applicability of Corrective Action Management Unit (CAMU) Regulations." to Subpart S of Part 264;
4) Redesignating Section 264.552 as Section 264.551, and revising the section heading and paragraph (a) introductory text;
5) Adding a new Section 264.552 "Corrective Action Management Units (CAMU)" to Subpart S of Part 264;
6) Revising paragraph (b), and adding subparagraphs (b)(1) and (b)(2) of § 264.553 Temporary Units (TU);
7) Adding paragraph (a)(1), adding and reserving paragraph (a)(2), and revising paragraph (b) of § 264.554 Staging Piles; and
8) Revising § 100.21(e) and § 100.26(d)(3) to add a cite reference to § 264.551.

Colorado is not adopting a state analog at this time for the optional federal provisions of 40 CFR § 264.555"Disposal of CAMU-eligible wastes in permitted hazardous waste landfill." The § 264.555 requirements are less stringent than existing requirements, and Colorado is evaluating the legal and policy issues related to these requirements. Colorado may propose state analogs to these federal provisions be adopted at a later date.

The Commission has modified the EPA CAMU rule to be more stringent in several respects. The Commission finds that these more stringent provisions are necessary to protect the public health and environment of the state. The rationale supporting adoption of each of these more stringent provisions is set forth below.

Colorado's definition of "CAMU-eligible waste" is more stringent than the federal definition of 40 CFR 264.552(a)(1). Unlike the federal provision, § 264.552(a)(1) of the Colorado hazardous waste regulations does not allow:

(1) management in a CAMU of wastes that are first placed in tanks, containers, or other non-land based units as part of cleanup; or
(2) management in a CAMU of containers that are excavated during the course of cleanup. In both cases, however, if the wastes in (or placed in) the tanks, containers, or other non-land-based units are chemically and physically similar to associated contaminated media, they are considered CAMU-eligible wastes.

This amendment to the EPA rule prevents disposal of highly concentrated waste in the CAMUs. Highly concentrated wastes are more likely to leach or pose incompatibility problems. Further, allowing disposal of concentrated wastes in a CAMU does not appear to be necessary to facilitate use of CAMUs. EPA's analysis of CAMUs approved under the 1993 CAMU rule showed no evidence that waste in intact containers had ever been placed in a CAMU. See 67 Fed. Reg. 2969. Finally, EPA's rationale for adopting this provision -- that if facility owners were not allowed to place wastes in intact or substantially intact containers, tanks, etc. in CAMUs, they would simply leave them in place -- is misplaced. In most (if not all) cases, CAMUs would only be considered at sites where the Division has corrective action authority. At such sites, the decision whether it is acceptable to leave buried drums in place lies with the Division, not the facility owner/operator.

Colorado is adopting a state analog which is more stringent than the minimum design requirements of 40 CFR 264.552(e)(3). The federal regulations specify a particular engineering design for a disposal CAMU: a composite liner and leachate collection system. The federal rule does allow for alternative CAMU design requirements that are at least as effective as the liner/leachate collection system set forth in the federal rule. The state regulation is more stringent because designation of a disposal CAMU triggers the applicability of Colorado's Hazardous Waste Siting Act, § 25-15-201 et seq. Pursuant to that Act, Colorado previously promulgated performance-based standards for hazardous waste disposal sites that are more stringent than the engineering design set forth in the federal CAMU rule. Because any CAMUs designated under § 264.552 would have to meet these more stringent standards in any case, the engineering design set forth in the federal rule is irrelevant. Therefore, the state CAMU rule incorporates the Siting Act's narrative, performance based standards as the minimum design standards for CAMUs.

In addition, the Commission notes that an alternative design may often be required, as experience in Colorado shows that the prescriptive design in the federal rule may not be compatible with CAMU-eligible wastes. For example, at the Rocky Mountain Arsenal, the prescriptive design promulgated by EPA would not have provided reasonable assurance that the wastes would remain isolated within the designated disposal area for the CAMU. See "Modeling of Four Different Landfill Liners in Support of the 1,000 Year Protectiveness of the Environment Criteria for the Rocky Mountain Arsenal CAMU Landfill," M. Schnarr, January 26, 1996 (analysis of a more robust composite liner than that proposed by EPA demonstrated that the liner was not adequate to meet Part 2 siting standards. This document is on file with the Division).

In adopting a state analog to 40 CFR § 264.552(e)(4)(i)(A)(1), Colorado revised the defining criteria for principal hazardous constituents (PHCs) to specify that the Director will designate as principal hazardous constituents:

(1) carcinogens that pose a potential direct risk from combined exposure pathways at the site at or above 1 x 10-4 using an unrestricted use exposure scenario; and
(2) non-carcinogens that pose a potential direct risk from combined exposure pathways at the site an order of magnitude or greater than their reference concentration using an unrestricted use exposure scenario. This is more stringent than the 1 x 10-3 risk level used in the federal provision that is based only on an ingestion or inhalation exposure pathway. The 10-3 level in the CAMU rule is significantly less stringent than other remedial programs, and the decision not to consider risks from all pathways is likewise less stringent. For example, the National Oil and Hazardous Substances Pollution Contingency Plan ( 40 CFR Part 300) (NCP) indicates that acceptable exposure levels for suspected carcinogens are "generally concentration levels that represent an excess upper bound lifetime cancer risk to an individual of between 10-4 and 10-6" and that the 10-6 level shall be used as the point of departure for determining remediation goals. Further, the 10-4 level is consistent with Colorado's approach to site remediation at sites not using CAMUs, as set forth in CDPHE's Corrective Action Guidance Document.

In adopting a state analog to 264.552(e)(6)(v), Colorado added an additional, more stringent requirement that CAMUs in which waste will remain after closure must have an environmental covenant pursuant to § 25-15-320, C.R.S. This provision is necessary because such CAMUs meet the statutory threshold for requiring an environmental covenant. See § 25-25-320(2), C.R.S.

This Basis and Purpose incorporates by reference the preamble language for the Environmental Protection Agency regulations published in the Federal Register at 67 FR 2962-3029, January 22, 2002.

Statement of Basis and Purpose - Rulemaking Hearing of January 11, 2005


6 CCR 1007-3-8.54
37 CR 24, December 25, 2014, effective 3/2/2015 38 CR 11, June 10, 2015, effective 6/30/2015 39 CR 05, March 10, 2016, effective 3/30/2016 39 CR 11, June 10, 2016, effective 6/30/2016 40 CR 06, March 25, 2017, effective 4/14/2017 40 CR 11, June 10, 2017, effective 6/30/2017 40 CR 21, November 10, 2017, effective 11/30/2017 41 CR 06, March 25, 2018, effective 4/14/2018 41 CR 11, June 10, 2018, effective 6/30/2018 41 CR 24, December 25, 2018, effective 1/14/2019 42 CR 06, March 25, 2019, effective 4/14/2019 42 CR 06, March 25, 2019, effective 5/30/2019 42 CR 11, June 10, 2019, effective 6/30/2019 43 CR 12, June 25, 2020, effective 7/15/2020 44 CR 06, March 25, 2021, effective 4/14/2021 44 CR 11, June 10, 2021, effective 6/30/2021 44 CR 24, December 25, 2021, effective 1/14/2022 45 CR 11, June 10, 2022, effective 6/30/2022 45 CR 17, September 10, 2022, effective 9/10/2022 45 CR 17, September 10, 2022, effective 9/30/2022 45 CR 23, December 10, 2022, effective 1/30/2023

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