REGULATION NO. 35 
CLASSIFICATIONS AND NUMERIC STANDARDS FOR 

GUNNISON AND LOWER DOLORES RIVER BASINS 

. . . .
35.6	TABLES
. . . .

STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS
REGION: 10

BASIN: Upper Gunnison River 	Desig	Classifications	NUMERIC STANDARDS	TEMPORARY
MODIFICATIONS
AND
QUALIFIERS	
			PHYSICAL
and
BIOLOGICAL	INORGANIC
mg/l	METALS
ug/l		
Stream Segment Description							

12. Mainstem of Coal Creek, including all tributaries and wetlands from a point immediately below the Crested Butte Water Supply intake which is above the confluence with the Mount Emmons/Red Lady Basin drainage to the confluence with the Slate River, with the exception of Wildcat Creek.
		Aq Life Cold 1
Recreation E
Water Supply
Agriculture
	T=TVS(CS-I) oC
D.O.=6.0 mg/l
D.O.(sp)=7.0 mg/l
pH=6.5-9.0
E.Coli=126/100ml
	NH3(ac/ch)=TVS
Cl2(ac)=0.019
Cl2(ch)=0.011
CN=.005
	S=0.002
B=0.75
NO2=0.05
NO3=10
Cl=250
SO4=WS
	As(ac)=340
As(ch)=0.02(Trec)
Cd(ac)=TVS(tr)
Cd(ch)=TVS
CrIII(ac)=50(Trec)
CrIII(ac/ch)=TVS
CrVI(ac/ch)=TVS
Cu(ac/ch)=TVS
	Fe(ch)=WS(dis)
Fe(ch)=1000(Trec)
Pb(ac/ch)=TVS
Mn(ac/ch)=TVS
Mn(ch)=191(dis)
Hg(ch)=0.01(tot)
Mo(ch)=160(Trec)
Ni(ac/ch)=TVS
Se(ac/ch)=TVS
	Ag(ac)=TVS
Ag(ch)=TVS(tr)
Zn(ac/ch)=TVS
	Temporary Modifications: 
Type A
As(ch)=current conditions
Expiration date
June 30, 2014

Type B
Cd(ch)=2.1, Cu(ch) = current conditions 
Zn(ch) = 440
Expiration date
June 30, 2016

35.35	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
Upper Gunnison River Basin Segment 12: 
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.
During the September 10, 2012 Rulemaking, the Commission adopted Type B Temporary Modifications for chronic cadmium, chronic copper and chronic zinc with expiration dates of June 30, 2013.  Since that time, U.S. Energy has worked with the Division and interested parties to develop a sampling plan to identify the natural and human-induced sources of cadmium, copper and zinc in the portion of the Coal Creek watershed affecting water quality in Segment 12 and to assess the extent to which human-induced sources are reversible, including measurable loads from wasterock piles and exploration shafts.  U.S. Energy will evaluate a range of alternatives including treatment of contaminated water, whether surface or groundwater, including collection and treatment at the Keystone Mine site.  Among other possible metals loading sources, the sampling plan includes a preliminary investigation of groundwater that may be originating from flooded workings within the historic Keystone Mine. The sampling plan includes efforts to evaluate the extent to which metals concentrations in groundwater within and immediately downgradient of the flooded mine workings are being affected by historic mining activity. If such effects are identified, or if preliminary results are inconclusive as to the effects of the flooded mine workings, U.S. Energy will develop plans for further investigation and characterization of metals loading to Segment 12 from the mine area. The Commission believes the sampling plan is sufficiently detailed and otherwise adequate to support extension of the Temporary Modifications until June 30, 2016. This should provide sufficient time to complete the proposed sampling and data analysis and to develop the other information needed (including a use attainability analysis) to set site specific water quality standards within a reasonable period. This will also ensure that progress towards (i) completing the initial investigation of the flooded mine workings, (ii) developing and implementing plans for further study of potential loading to Segment 12, and (iii) collecting sufficient information to support adoption of site-specific water quality standards in 2016 will be reviewed in the annual Temporary Modification hearings in December 2014 and December 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