REGULATION NO.  37
CLASSIFICATIONS AND NUMERIC STANDARDS
FOR
LOWER COLORADO RIVER BASIN 
. . . .
37.6	TABLES
. . . .

STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS
REGION:11

BASIN:  Lower Colorado River	

Desig	

Classifications	
NUMERIC STANDARDS	
TEMPORARY
MODIFICATIONS
AND
QUALIFIERS	

Stream Segment Description			PHYSICAL
and
BIOLOGICAL
	
INORGANIC
mg/l	
METALS
ug/l		
4e.	Mainstem of Dry Creek including all tributaries and wetlands from the source to immediately above the Last Chance Ditch.	UP	Aq Life Cold 2
Recreation N
Agriculture	T=TVS(CS-II) oC
D.O.=5.0 mg/l
pH=6.5-9.0
E.Coli=630/100ml	NH3(ac/ch)=TVS
Cl2(ac)=0.019
Cl2(ch)=0.011
CN=0.005	S=0.002
B=0.75
NO2=0.05
NO3=100	As(ac)=340
As(ch)=100(Trec)
Cd(ac/ch)=TVS
CrIII(ac/ch)=TVS
CrVI(ac/ch)=TVS
Cu(ac/ch)=TVS	Fe(ch)=1000(Trec)
Pb(ac/ch)=TVS
Mn(ac/ch)=TVS
Hg(ch)=0.01(tot)	Ni(ac/ch)=TVS
Se(ac/ch)=TVS
Ag(ac/ch)=TVS
Zn(ac/ch)=TVS	Temporary Modifications:
Cu(ac/ch)=existing quality
Fe(ch)=existing quality(Trec)
(Type iii)
Expiration 12/31/2015 	

37.30	STATEMENT OF BASIS SPECIFIC STATUTORY AUTHORITY AND PURPOSE DECEMBER 10, 2012 RULEMAKING; FINAL ACTION JANUARY 14, 2013 EFFECTIVE DATE JUNE 30, 2013
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, 2014, to determine whether the temporary modification should be modified, eliminated or extended.  
Temporary modifications standards on two segments were reviewed.  The Basic Standards Statement of Basis for the 2010 hearing records the Commission’s intent regarding temporary modifications. (see 31.48 at I.A)
Since temporary modifications have no impact on other aspects of Colorado’s water quality management program such as the 303(d) list, the Non-point Source Program or the Total Maximum Daily Load (TMDL) Program, it is fitting that temporary modifications only be used where there are permitted discharges that would face unreasonable consequences in the absence of a temporary modification (e.g., a permit compliance schedule to meet a standard that is significantly uncertain).
No action:  The Commission took no action on the temporary modifications on the following segment which is receiving waters for permitted discharges.  
Lower Colorado segment 13b:  Temperature (expiration date 6/30/2013)
Lower Colorado River segment 4e, Dry Creek:  Tri-State Generation and Transmission Association, Inc. proposed extending the temporary modifications for copper and iron for Dry Creek. The Commission considered Tri-State’s plan to eliminate the need for the temporary modification. Tri-State is working to resolve uncertainty and is making progress in addressing this segment. The Commission extended the expiration date to 12/31/2015.
PARTIES TO THE RULEMAKING HEARING
1.	City of Pueblo
2.	Seneca Coal Company
3.	Tri-State Generation and Transmission Association	
4.	Eagle River Water and Sanitation District
5.	Board of County Commissioners for the County of Gunnison, Colorado
6.	Colorado Parks and Wildlife
7.	High Country Citizens’ Alliance
8.	Bill Thiebaut, DA for 10th Judicial District and the Office of the DA for the 10th Judicial District
9.	City of Colorado Springs
10.	Town of Crested Butte
11.	Upper Gunnison River Water Conservancy District
12.	U.S. Energy Corp.
13.	Gunnison County Stockgrowers Association, Inc.
14.	Environmental Protection Agency
15.	Cherokee Metropolitan District
16.	Fountain Sanitation District
17.	Lower Fountain Metropolitan Sewage Disposal District
18.	Monument Sanitation District
19.	Palmer Lake Sanitation District
20.	Town of Monument
21.	Academy Water and Sanitation District
22.	Tri-Lakes Wastewater Treatment Facility
23.	Town of Palmer Lake
24.	Woodmoor Water and Sanitation District No. 1
25.	Upper Monument Creek Regional Wastewater Treatment Facility