5 Colo. Code Regs. § 1002-34.47
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.
No action: The commission took no action on the temporary modifications on the following segments since they will be addressed in the basin wide hearing in June 2017.
Animas River Segment 3b: temporary modification of the cadmium, copper and zinc standards (expire 12/31/2017).
La Plata Segment 7a: temporary modification of the ammonia standards (expire 12/31/2018).
La Plata Segment 8c: temporary modification of the ammonia standards (expire 12/31/2018).
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 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.
San Juan River Segment 9a San Juan River Segment 11a Piedra River Segment 7 Los Pinos River Segment 5 Animas Florida River Segment 10a Animas Florida River Segment 13a Animas Florida River Segment 22 La Plata River Segment 2b La Plata River Segment 5a La Plata River Segment 12 Dolores River Segment 1 Dolores River Segment 2 Dolores River Segment 3 Dolores River Segment 4a Dolores River Segment 4b Dolores River Segment 5a Dolores River Segment 5b
PARTIES TO THE RULEMAKING HEARING
5 CCR 1002-34.47