COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT 
WATER QUALITY CONTROL COMMISSION 
5 CCR 1002-35
REGULATION NO. 35
CLASSIFICATIONS AND NUMERIC STANDARDS 
FOR 
GUNNISON AND LOWER DOLORES RIVER BASINS
. . . .
35.31	STATEMENT OF BASIS SPECIFIC STATUTORY AUTHORITY AND PURPOSE DECEMBER 2009 RULEMAKING REGARDING TEMPORARY MODIFICATIONS; FINAL ACTION FEBRUARY 8, 2010; EFFECTIVE DATE JUNE 30, 2010
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 to determine whether the temporary modification should be modified, eliminated or extended.
Ammonia:  Temporary modifications of ammonia standards were reviewed.  
Deleted:  Ammonia temporary modifications were deleted on the following segments because permits had recently been reissued for dischargers on the segments.  Compliance schedules in the permits are adequate to address any necessary treatment plant upgrade issues.  
Uncompahgre River Segments 4a and 4b
Lower Gunnison River segments 2
Detail added: Lower Gunnison River segment 4a: The following details were added to the tables: the chronic ammonia temporary modification was modified to clarify that the chronic standard’s value is 0.02 mg/l, rather than just “TVS old”; and an expiration date of 12/31/2011 was added to the ammonia temperature temporary modification.
Other Parameters:  Temporary modifications of other parameters were also reviewed.  
Deleted:  temporary modifications were deleted on the following segments because no permitted discharge has been identified that needs a temporary modification  
Uncompahgre segment  4c	selenium
Lower Gunnison segment 4b	selenium
Detail added:  An expiration date was added to the temperature temporary modification on San Miguel River segment 4b
Extension of expiration dates:  The Commission has decided to delay the basin-wide review of water quality classifications and standards for this basin until June 2012, to accommodate an issue-specific rulemaking for nutrient criteria in June 2011.  Consistent with that decision, the expiration dates of the temporary modifications on the following segments that are currently scheduled to expire on 12/31/2011 are extended to 12/31/2012.  These will be reviewed again in the December 2010 and December 2011 Temporary Modification hearing.
Upper Gunnison segments 8, 12, and 16 
North Fork Gunnison segments 3, 5, and 6b 
Uncompahgre segments 3a, 4b, and 12 
Lower Gunnison segments 2, 4a (selenium only), and 7 
San Miguel River segments 2, 3b and 4b
The Commission would like to emphasize that its intent and expectation is that the issues that necessitated adoption of these temporary modifications should be resolved as soon as possible and in a manner that takes full advantage of the opportunities provided by the December 2010 and December 2011 reviews of temporary modifications.  The Commission recognizes that it is important to resolve uncertainty regarding the underlying standards so that temporary modifications can be eliminated and any needed pollution controls can be put in place in a timely manner.
PARTIES TO THE RULEMAKING
1.	City of Grand Junction
2.	City of Colorado Springs and Colorado Springs Utilities
3.	Tri-Lakes, Upper Monument, Security and Fountain Wastewater Treatment Facilities
4.	Paint Brush Hills Metropolitan District
5.	Pueblo West Metropolitan District
6.	City of La Junta
7.	Seneca Coal Company
8.	Tri-State Generation and Transmission Association
9.	Plum Creek Wastewater Authority
10.	Centennial Water and Sanitation District
11.	City and County of Broomfield
12.	City of Fort Collins
13.	Metro Wastewater Reclamation District
14.	City of Black Hawk and the Black Hawk/Central City Sanitation District
15.	Colorado Division of Wildlife
16.	U.S. Environmental Protection Agency