REGULATION NO. 32 
CLASSIFICATIONS AND NUMERIC STANDARDS 
FOR 
ARKANSAS RIVER BASIN
. . . .
32.6 	TABLES
. . . .
STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS
REGION: 13

BASIN: UPPER ARKANSAS RIVER	Desig	Classifications	NUMERIC STANDARDS	TEMPORARY
MODIFICATIONS
AND QUALIFIERS	
Stream Segment Description			PHYSICAL 
and 
BIOLOGICAL	INORGANIC
mg/l	METALS
ug/l		

2c.	Mainstem of the Arkansas River from a point immediately above the confluence with the Lake Fork to a point immediately above the confluence with Lake Creek.	
9/30/00 
Base-line
does not
apply
	
Aq Life Cold 1
Recreation E
Agriculture	
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=0.005
S=0.002
B=0.75
NO2=0.05	
As(ac)=340
As(ch)=7.6(Trec)
Cd(ac)=1.136672-(ln(hardness)*0.041838)*e(0.9151*ln(hardness)-3.6236)
Cd(ch)=(1.101672-[ln(hardness)*0.041838])*e(0.7998[In hardness]-3.1725)
CrIII(ch)=100(Trec)
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)=TVS
Ag(ch)=TVS(tr)
Zn(ac)=
0.978*e(0.8537[ln(hardness)]+2.2178)
Zn(ch)=
0.986*e(0.8537[ln(hardness)]+2.0469)	
 	
STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS
REGION: 13

BASIN: MIDDLE ARKANSAS RIVER	Desig	Classifications	NUMERIC STANDARDS	TEMPORARY
MODIFICATIONS
AND QUALIFIERS	
Stream Segment Description			PHYSICAL 
and 
BIOLOGICAL	INORGANIC
mg/l	METALS
ug/l		

4b.	Mainstem of Rock Creek, Salt Creek and Peck Creek from their sources to the confluence with the Arkansas River.	
UP	
Aq Life Warm 2
Recreation E
Agriculture
	
D.O.=5.0 mg/l
pH=6.5-9.0
E.Coli=126/100ml	
NH3(ac/ch)=TVS
CL2(ac)=0.019
CL2(ch)=0.011
CN=0.005
S=0.002	
B=0.75
NO2=0.05
	
As(ch)=100(Trec)
As(ac)=340
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

5.	Mainstem of the Saint Charles River, including all tributaries, wetlands, lakes and reservoirs, from the source to a point immediately above the CF&I diversion canal near Burnt Mill.	
UP	
Aq Life Cold 1
Recreation E
Water Supply
Agriculture	
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=0.005
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)
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)=WS(dis)	
Hg(ch)=0.01(tot)
Ni(ac/ch)=TVS
Se(ac/ch)=TVS
Ag(ac)=TVS
Ag(ch)=TVS(tr)
Zn(ac/ch)=TVS	
	
STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS
REGION: 13

BASIN: MIDDLE ARKANSAS RIVER	Desig	Classifications	NUMERIC STANDARDS	TEMPORARY
MODIFICATIONS
AND QUALIFIERS	
Stream Segment Description			PHYSICAL 
and 
BIOLOGICAL	INORGANIC
mg/l	METALS
ug/l		

10.	Mainstem of Sixmile Creek from the source to the confluence with the Arkansas River.	
UP	
Aq Life Warm 2
Recreation E
Agriculture	
D.O. = 5.0 mg/l
pH = 6.5-9.0 
E.Coli=126/100ml
	
NH3(ac/ch)=TVS
CL2(ac)=0.019
CL2(ch)=0.011	
CN=0.005
S=0.002
B=0.75
NO2=0.5	
As(ch)=100(Trec)
As(ac)=340
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

12.	Mainstem of Huerfano River from the confluence with Muddy Creek near Gardner to the confluence with the Arkansas River.	
UP	
Aq Life Warm 2
Recreation E
Agriculture	
D.O. = 5.0 mg/l
pH = 6.5-9.0
E.Coli=126/100ml
	
NH3(ac/ch)=TVS
CL2(ac)=0.019
CL2(ch)=0.011	
CN=0.005
S=0.002
B=0.75
NO2=0.5
	
As(ch)=100(Trec)
As(ac)=340
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

14.	Mainstem of the Cucharas River from the point of diversion for the Walsenburg public water supply to the outlet of Cucharas Reservoir.	
	
Aq Life Warm 1
Recreation E
Agriculture	
D.O. = 5.0 mg/l
pH = 6.5-9.0
E.Coli=126/100ml
	
NH3(ac/ch)=TVS
CL2(ac)=0.019
CL2(ch)=0.011	
CN=0.005
S=0.002 B=0.75
NO2=0.5
	
As(ac)=340
As(ch)=7.6(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

18a	Mainstem of Boggs Creek from the source to Pueblo Reservoir.		
Aq Life Warm 1
Recreation E
Water Supply
Agriculture
	
D.O.=5.0 mg/l
pH=6.5-9.0
E.Coli=126/100ml
	
NH3(ac/ch)=TVS
CL2(ac)=0.019
CL2(ch)=0.011
CN=0.005
S=0.002	
B=0.75
NO2=0.5
NO3=10
Cl=250
SO4=WS	
As(ac)=340
As(ch)=0.02(Trec)
Cd(ac/ch)=TVS
CrIII(ac)=50(Trec)
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)=WS(dis) 	
Hg(ch)=0.01(tot)
Ni(ac/ch)=TVS
Se(ac/ch)=TVS
Ag(ac)=TVS
Ag(ch)=TVS(tr)
Zn(ac/ch)=TVS	

STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS
REGION: 13

BASIN: LOWER ARKANSAS RIVER	Desig	Classifications	NUMERIC STANDARDS	TEMPORARY
MODIFICATIONS
AND QUALIFIERS	
Stream Segment Description			PHYSICAL 
and 
BIOLOGICAL	INORGANIC
mg/l	METALS
ug/l		

1a.	Mainstem of the Arkansas River from a point immediately above the confluence with Fountain Creek to immediately above the Colorado Canal headgate near Avondale.	
UP	
Aq Life Warm 2
Recreation E
Water Supply
Agriculture	
D.O. = 5.0 mg/l
pH = 6.5-9.0
E.Coli=126/100ml
	
NH3(ac/ch)=TVS
CL2(ac)=0.019
CL2(ch)=0.011
CN=0.005
S=0.002	
B=0.75
NO2=0.5
NO3=10
Cl=250
SO4=329	
As(ac)=340
As(ch)=0.02-10(Trec)
Cd(ac/ch)=TVS
CrIII(ac)=50(Trec)
CrVI(ac/ch)=TVS
Cu(ac/ch)=TVS	
Fe(ch)=WS(dis)
Fe(ch)=2765(Trec)
Pb(ac/ch)=TVS
Mn(ac/ch)=TVS
Mn(ch)=WS(dis)
Hg(ch)=0.01(tot)	
Ni(ac/ch)=TVS
Se(ac)=19.1
Se(ch)=14.1
Ag(ac/ch)=TVS
Zn(ac/ch)=TVS	
Temporary modifications:
type (i)
Se(ac/ch) = existing quality;
SO4 = existing quality.  Expiration date of 6/30/2016.	

4.	Mainstem of the Apishapa River from I-25 to the confluence with the Arkansas River; mainstem of Timpas Creek from the source to the Arkansas River; mainstem of Lorencito Canyon, from the source to the confluence with the Purgatoire River.	
UP	
Aq Life Warm 2
Recreation E
Agriculture	
D.O. = 5.0 mg/l
pH = 6.5-9.0
  E.Coli=126/100ml	
NH3(ac/ch)=TVS
CL2(ac)=0.019
CL2(ch)=0.011
	
CN=0.005
S=0.002
B=0.75
NO2=0.5	
As(ch)=100(Trec)
As(ac)=340
Cd(ac/ch)=TVS
CrIII(ac/ch)=TVS
CrVI(ac/ch)=TVS
Cu(ac/ch)=TVS	
Fe(ch)=1805(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

STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS
REGION: 13

BASIN: LOWER ARKANSAS RIVER	Desig	Classifications	NUMERIC STANDARDS	TEMPORARY
MODIFICATIONS
AND QUALIFIERS	
Stream Segment Description			PHYSICAL 
and 
BIOLOGICAL	INORGANIC
mg/l	METALS
ug/l		

9a.	Mainstem of Adobe Creek and Gageby Creek from the source to the confluence with the Arkansas River; mainstem of Willow Creek from Highway 287 to the confluence with the Arkansas River; mainstem of Big Sandy Creek from the source to the El Paso/Elbert county line; mainstem of South Rush Creek from the source to the confluence with Rush Creek; mainstem of Middle Rush Creek from the source to the confluence with North Rush Creek, North Rush Creek from the source to the confluence with South Rush Creek; mainstem of Rush Creek to the Lincoln County Line, mainstem of Antelope Creek from the source to the confluence with Rush Creek; mainstems of Horse Creek, Buffalo Creek and Cheyenne Creek from their sources to their confluences with the Arkansas River; the West May Valley drain from the Fort Lyon Canal to the confluence with the Arkansas River.	
	
Aq Life Warm 1
Recreation E
Agriculture	
D.O. = 5.0 mg/l
pH = 6.5-9.0
E.Coli=126/100ml
	
NH3(ac/ch)=TVS
CL2(ac)=0.019
CL2(ch)=0.011
	
CN=0.005
S=0.002
B=0.75
NO2=0.5	
As(ac)=340
As(ch)=7.6(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

9b.	Mainstem of Apache Creek from the source to the confluence with the North Rusk Creek; mainstem of Breckenridge Creek from the source to the confluence with Horse Creek; mainstem of Little Horse Creek from the source to the confluence with Horse Creek; mainstem of Bob Creek; from the source to Meredith Reservoir; mainstems of Wildhorse Creek and Wolf Creek from their sources to their confluences with the Arkansas River; mainstem of Big Sandy Creek within Prowers County.	
UP	
Aq Life Warm 2
Recreation E
Agriculture	
D.O. = 5.0 mg/l
pH = 6.5-9.0
E.Coli=126/100ml
	
NH3(ac/ch)=TVS
CL2(ac)=0.019
CL2(ch)=0.011
	
CN=0.005
S=0.002 B=0.75
NO2=0.5	
As(ch)=100(Trec)
As(ac)=340
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

9c.	Mainstem of Rule Creek from the Bent/Las Animas county line to John Martin Reservoir; mainstem of Muddy Creek from the south boundary of the Setchfield State Wildlife Area to the confluence with Rule Creek; mainstem of Caddoa Creek from CC road to the confluence with the Arkansas River; mainstem Clay Creek from source to the confluence with the Arkansas; mainstem of Cat Creek to the confluence with Clay Creek; mainstem of Two Butte Creek from the source to the confluence with the Arkansas River, except for listings in segment 10; mainstem of Trinchera Creek from the source to the confluence with the Purgatoire River; mainstem of Mustang Creek from the source to the confluence with Apishapa River; mainstem of Chicosa Creek from the source to the Arkansas River; mainstem of Smith Canyon from the Otero/Las Animas county line to the confluence with the Purgatoire River.	
UP	
Aq Life Warm 2
Recreation E
Agriculture	
D.O.=5.0 mg/l
pH=6.5-9.0
E.Coli=126/100ml	
NH3(ac/ch)=TVS
CL2(ac)=0.019
CL2(ch)=0.011
	
CN=0.005
S=0.002 B=0.75
NO2=0.5	
As(ch)=100(Trec)
As(ac)=340
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

11.	John Martin Reservoir.	
	
Aq Life Warm 1
Recreation E
Water Supply
Agriculture	
D.O. = 5.0 mg/l
pH = 6.5-9.0 
E.Coli=126/100ml	
NH3(ac/ch)=TVS
CL2(ac)=0.019
CL2(ch)=0.011
CN=0.005
S=0.002	
B=0.75
NO2=0.5
 NO3=10
Cl=250
SO4=WS	
As(ac)=340
As(ch)=0.02(Trec)
Cd(ac/ch)=TVS
CrIII(ac)=50(Trec)
CrVI(ac/ch)=TVS
Cu(ac/ch)=TVS	
Fe(ch)=WS(dis)
Fe(ch)=1000(Trec)
Pb(ac/ch)=TVS
Mn(ch)=90(dis)
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	

32.50	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 of 36 standards on 30 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).
Deleted:  Temporary modifications were deleted on the following segments because there are no currently identified discharge permits on the segments.  
Upper Arkansas segment 2c
Middle Arkansas segments 4b, 5, 10, 12, 14, and 18a
Lower Arkansas segments 4, 9a, 9b, 9c, and 11
No action:  The Commission took no action on the temporary modifications on the following segments which are receiving waters for permitted discharges.  These temporary modifications will expire 12/31/2013.  The basin-wide review hearing is scheduled for June 2013 and it is anticipated that the remaining issues will be resolved in that hearing process.
Upper Arkansas segments 2b, 3, 8a, 8b, and 12a
Middle Arkansas segments 4c, 6,and 9
Fountain Creek segments 1a, 2a, 4, and 6

Lower Arkansas segments 1b, 1c, 5a, 6, and 7
Lower Arkansas River segment 1a:  The Commission retained the temporary modifications for selenium and sulfate equal to existing conditions for Lower Arkansas segment 1a and extended the expiration date to June 30, 2016.
As discussed in previous hearings (see 1998 and 2007 Statement of Basis) the selenium and sulfate issues in segment 1a are complicated.  Uncertainty regarding the appropriate underlying selenium standard continues with the delay in release of the federal 304(a) draft criteria.  In addition, the Commission reaffirms the determination that Pueblo’s discharge of intercepted ground water which contains selenium and sulfate results in a reduced load of selenium to the system.  
The Commission extended these temporary modifications to allow time for the City of Pueblo to pursue a discharger-specific variance or other permanent solution. The Commission recognizes that further developments before 2016 could complicate development of discharger-specific variances for selenium and sulfate. For example, depending on the criteria EPA develops, discharger-specific variances may not be necessary. In particular, the relationship between selenium and sulfate in EPA’s selenium criteria document could substantially affect standards development. If the application of EPA criteria and recalculation procedures result in site-specific standards that are attainable without causing more environmental harm than good, then discharger-specific variances would not be necessary.
The temporary modifications will be reviewed in the 2014 and 2015 annual reviews and can be resolved or extended in those proceedings.
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