5 Colo. Code Regs. § 1002-38.97
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, 2019 to determine whether the temporary modification should be modified, eliminated, or extended.
No action: The commission took no action on the temporary modifications on the following segments:
Upper South Platte Segment 3: temporary modification of the ammonia standard below the Florissant Wastewater Treatment Facility (expires 12/31/2017). The Town of Florissant obtained funding to upgrade its facility and a progress report indicated the facility is on track to comply with ammonia effluent limits. The commission took no action on this temporary modification and it was deleted from the table because it expires 12/31/2017.
Upper South Platte Segment 10a: temporary modifications of the copper (expires 12/31/2018; applies below the Plum Creek Water Reclamation Authority) and manganese (expires 6/30/2019) standards. Plum Creek Water Reclamation Authority continues to make progress on resolving the uncertainty underlying both temporary modifications. The commission made no change to the expiration date as the original time allotment was deemed adequate to resolve the uncertainty.
Clear Creek Segments 11, 14a, 14b, and 15: temporary modification of the temperature standard (expires 6/30/2019). MillerCoors continues to make progress on resolving the uncertainty. The commission made no change to the expiration date as the original time allotment was deemed adequate to resolve the uncertainty.
Clear Creek Segment 13b: temporary modification of the cadmium standard (expires 12/31/2018). Black Hawk and Central City Sanitation District continues to make progress on resolving the uncertainty. The commission made no change to the expiration date as the original time allotment was deemed adequate to resolve the uncertainty.
New temporary modifications of the arsenic standard:
Consistent with the actions taken in 2013, the commission adopted a temporary modification of the arsenic standard on segments on the following list, 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 rulemaking 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.
Cherry Creek Segment 3 Boulder Creek Segment 7b
PARTIES TO THE RULEMAKING HEARING
5 CCR 1002-38.97