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Water: State, Tribal & Territorial Standards

Repository of Documents: Colorado

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The Basic Standards And Methodologies for Surface Water, Regulation No. 31 (PDF) (178 pp, 2MB)
(Effective December 31, 2005) This regulation provides basic water quality standards, an antidegradation rule and implementation process, and a system for classifying state surface waters, for assigning water quality standards, for granting temporary modifications, and for periodic review of the classifications and standards.
Colorado River Salinity Standards, Regulation No. 39 (PDF) (7 pp, 596K)
The regulation establishes water quality standards for salinity in the Colorado River Basin.
Water Quality Standards for Salinity--Colorado River System, June 1999 (PDF) (109 pp, 7.4MB)
Water Quality Standards for Salinity--Colorado River System, October 1999 (PDF) (49 pp, 2.8MB)

Classifications and Numeric Standards

The following regulations provide classifications and numeric water quality criteria for the indicated rivers and basins.

Classifications And Numeric Standards for Arkansas River Basin, Regulation No. 32 (2006) (PDF) (72 pp, 304K) and Tables (PDF) (16 pp, 238K)
(Effective March 2, 2006)
Classifications And Numeric Standards for Upper Colorado River Basin And North Platte River, Regulation No. 33 (2006) (PDF) (83 pp, 183K) and Tables (PDF) (15 pp, 98K)
(Effective March 2, 2006)
Classifications And Numeric Standards for San Juan River And Dolores River Basins, Regulation No. 34 (2006) (PDF) (46 pp, 334K) and Tables (PDF) (19 pp, 108K)
(Effective March 2, 2006)
Classifications And Numeric Standards for San Juan Gunnison And Lower Dolores River Basins, Regulation No. 35 (2006) (PDF) (92 pp, 478K)
(Effective March 2, 2006)
Classifications And Numeric Standards for Rio Grande Basin, Regulation No. 36 (PDF) (49 pp, 152K) and Tables (PDF) (11 pp, 113K)
(Effective December 6, 2002)
Classifications And Numeric Standards for Lower Colorado River Basin, Regulation No. 37 (2006) (PDF) (62 pp, 489K) and Tables (PDF) (11 pp, 90K)
(Effective March 2, 2006)
Classifications And Numeric Standards for South Platte River Basin, Laramie River Basin, Republican River Basin, Smoky Hill River Basin, Regulation No. 38 (2006) (PDF) (147 pp, 1.5MB) and Tables (PDF) (28 pp, 1.1MB)
(Effective March 2, 2006)

Colorado's water quality standards are applicable to "waters of the State". In some limited instances, the definition adopted by Colorado for "waters of the State" as part of its water quality standards may result in water quality standards that are more comprehensive than required under section 303(c) of the Clean Water Act and the implementing federal regulations. EPA has included the State's water quality standards in their entirety here for context and as supplementary information for the reader.

Colorado water quality standards apply to all waters within the State of Colorado, with the exception of those waters that are within Indian Country, as defined in 18 U.S.C. Section 1151. EPA's approval of Colorado's water quality standards was not intended as an action to approve or disapprove water quality standards applying to waters within Indian Country. EPA, or eligible Indian Tribes, as appropriate, will retain responsibilities for water quality standards within Indian Country. Information on Tribal Water Quality Standards.

Archive

The Basic Standards And Methodologies for Surface Water, Regulation No. 31 (PDF) (671K)
(Effective August 1, 2001) This regulation provides basic water quality standards, an antidegradation rule and implementation process, and a system for classifying state surface waters, for assigning water quality standards, for granting temporary modifications, and for periodic review of the classifications and standards.
Classifications And Numeric Standards for Arkansas River Basin, Regulation No. 32 (2005) (PDF) (80 pp, 899K) and Tables (PDF) (16 pp, 907K)
(Effective January 7, 2005)
Classifications And Numeric Standards for Upper Colorado River Basin And North Platte River, Regulation No. 33 (2005) (PDF) (80 pp, 175K) and Tables (PDF) (13 pp, 137K)
(Effective August 9, 2005)
Classifications And Numeric Standards for San Juan River And Dolores River Basins, Regulation No. 34 (2002) (PDF) (8 pp, 60K), Statement of Basis and Purpose (PDF) (40 pp, 169K) and Tables (PDF) (19 pp, 140K)
(Effective October 1, 2002)
Classifications And Numeric Standards for San Juan Gunnison And Lower Dolores River Basins, Regulation No. 35 (2002) (PDF) (50 pp, 198K) and Tables (PDF) (14 pp, 139K)
(Effective February 8, 2002)
Classifications And Numeric Standards for Lower Colorado River Basin, Regulation No. 37 (PDF) (62 pp, 455K) and Tables (PDF) (17 pp, 95K)
(Effective October 24, 2003)
Classifications And Numeric Standards for South Platte River Basin, Laramie River Basin, Republican River Basin, Smoky Hill River Basin, Regulation No. 38 (PDF) (147 pp, 1.3MB) and Tables (PDF) (28 pp, 1.1MB)
(Effective December 21, 2004)

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