5 Colo. Code Regs. § 1002-34.43
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
In 2010, the Commission adopted the discharger specific variance provisions at Regulation 31.7(4), which allow a temporary water quality standard to be adopted in cases where water quality based effluent limits are not feasible to achieve. A DSV is a hybrid standard that maintains the long-term water quality goal of fully protecting all designated uses, while temporarily authorizing an alternative effluent limit (AEL) to be developed for a specific pollutant and specific point source discharge where compliance with the water quality based effluent limit (WQBEL) is not feasible.
In reliance upon Durango West Metropolitan District #2's (DWMD's) commitment to implement upgrades and a continued maintenance program, the Commission adopted a DSV for Animas and Florida Segment 13b for ammonia that represents the highest degree of protection of the classified use that is feasible for DWMD. For ammonia, the monthly chronic total ammonia effluent limits for DWMD shall not be more restrictive than 15 mg/L prior to 12/31/2024. The Commission expects that DWMD will submit a progress report for the San Juan Basin Issues Formulation Hearing in November 2016 and expects that report to include information regarding whether there are any downstream domestic water supply wells that are impacted by the discharge.
PARTIES TO THE RULEMAKING HEARING
5 CCR 1002-34.43