5 Colo. Code Regs. § 1002-36.39
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, 2018, to determine whether the temporary modification should be modified, eliminated or extended.
Temporary modifications of standards on Rio Grande Segment 4a and Segment 7 which expire 12/31/2018, were reviewed. The commission took no action on the temporary modifications on these two segments impacted by the historic Creede mining district. Both the Town of Creede and Rio Grande Silver continue to make progress on resolving the uncertainty.
New Temporary Modifications of the Arsenic Standard, Closed Basin segment 3. Consistent with the actions taken in 2013, the commission adopted a temporary modification of the arsenic standard on this segment with an expiration date of 12/31/2021. At the April 8, 2013 rulemaking, the commission heard testimony that concurred with the finding from a December 13, 2011 hearing that an initial reasonable lower limit of treatment technology for arsenic is 3.0 µg/L, pending further investigation by the division, dischargers and stakeholders. The temporary modification was established by the commission to allow for a temporarily less stringent application of the chronic arsenic standard in control requirements for both existing discharges and new or increased discharges.
Closed Basin Segment 3
PARTIES TO THE RULEMAKING HEARING
5 CCR 1002-36.39