5 Colo. Code Regs. § 1002-38.103
The provisions of C.R.S. 25-8-202(1)(a), (b) and (2); 25-8-203; 25-8-204; and 25-8-402; provide the specific statutory authority for adoption of these regulatory amendments. The commission also adopted in compliance with 24-4-103(4) C.R.S. the following statement of basis and purpose.
BASIS AND PURPOSE
Pursuant to the requirements in the Basic Standards (at 31.7(3)), the commission reviewed the status of temporary modifications scheduled to expire before December 31, 2022 to determine whether the temporary modification should be modified, eliminated, or extended.
For the temporary modifications set to expire after the effective date of this hearing, the commission reviewed progress toward resolving the uncertainty in the underlying standard and/or the extent to which conditions are a result of natural or anthropogenic conditions, and evaluated whether the temporary modifications were still justified.
The commission took no action on the following temporary modifications:
Upper South Platte Segment 15 (COSPUS15): temporary modification of the acute and chronic temperature standards (expires 12/31/2021). Metro Wastewater Reclamation District continues to make progress to resolve the uncertainty in the temperature standards and is working to develop a proposal for a discharger specific variance. This temporary modification was extended by one year (to 12/31/2021) during the June 2020 Regulation No. 38 rulemaking hearing; as part of that hearing, Metro provided an update regarding progress being made in implementing the plan to resolve uncertainty and demonstrating the ongoing justification for the temporary modifications, including demonstrated instream nonattainment and predicted compliance issues. The commission made no change to the expiration date, as the original time allotment was deemed adequate to resolve the uncertainty.
St. Vrain Segment 6a (COSPSV06a): temporary modification of the chronic iron standard (expires 6/30/2023). As included in its plan to resolve uncertainty, Raytheon Company provided an update on its work to resolve the uncertainty in the chronic iron standard. Raytheon continues to make progress on resolving the uncertainty and eliminating the need for the temporary modification and determining the extent to which the existing quality is the result of natural or irreversible human-induced conditions. The commission made no change to the expiration date, as the original time allotment was deemed adequate to resolve the uncertainty.
5 CCR 1002-38.103