Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-34 - REGULATION NO. 34 - CLASSIFICATIONS AND NUMERIC STANDARDS FOR SAN JUAN AND DOLORES RIVER BASINS
Section 5 CCR 1002-34.5 - BASIC STANDARDS

Current through Register Vol. 47, No. 17, September 10, 2024

(1) Temperature

All waters of the San Juan/Dolores River Basin are subject to the following standard for temperature. (Discharges regulated by permits, which are within the permit limitations, shall not be subject to enforcement proceedings under this standard). Temperature shall maintain a normal pattern of diurnal and seasonal fluctuations with no abrupt changes and shall have no increase in temperature of a magnitude, rate, and duration deemed deleterious to the resident aquatic life. This standard shall not be interpreted or applied in a manner inconsistent with section 25-8-104, C.R.S.

(2) Qualifiers

See Basic Standards and Methodologies for Surface Water for a listing of organic standards at 31.11 Table B and metal standards found at 31.16 Table III. The column in the tables headed "Water + Fish" are presumptively applied to all aquatic life class 1 streams which also have a water supply classification, and are applied to aquatic life class 2 streams which also have a water supply classification, on a case-by-case basis as shown in the Appendix 34-1. The column in the tables at 31.11 and 31.16 Table III headed "Fish Ingestion" is presumptively applied to all aquatic life class 1 streams which do not have a water supply classification, and are applied to aquatic life class 2 streams which do not have a water supply classification, on a case-by-case basis as shown in Appendix 34-1.

(3) Uranium

(a) All waters of the San Juan/Dolores River Basin, are subject to the following basic standard for uranium, unless otherwise specified by a water quality standard applicable to a particular segment. However, discharges of uranium regulated by permits which are within these permit limitations shall not be a basis for enforcement proceedings under this basic standard.

(b) Uranium level in surface waters shall be maintained at the lowest practicable level.

(c) In no case shall uranium levels in waters assigned a water supply classification be increased by any cause attributable to municipal, industrial, or agricultural discharges so as to exceed 16.8-30 µg/L or naturally-occurring concentrations (as determined by the State of Colorado), whichever is greater.
(i) The first number in the 16.8-30 µg/L range is a strictly health-based value, based on the Commission's established methodology for human health-based standards. The second number in the range is a maximum contaminant level, established under the federal Safe Drinking Water Act that has been determined to be an acceptable level of this chemical in public water supplies, taking treatability and laboratory detection limits into account. Control requirements, such as discharge permit effluent limitations, shall be established using the first number in the range as the ambient water quality target, provided that no effluent limitation shall require an "end-of-pipe" discharge level more restrictive than the second number in the range. Water bodies will be considered in attainment of this standard, and not included on the Section 303(d) List, so long as the existing ambient quality does not exceed the second number in the range.

(4) Indian Reservations

Some of the waterbodies in the San Juan/Dolores River Basin cross boundaries of Indian Reservations of the Southern Ute and Ute Mountain Ute Tribes. The Commission has included water quality classifications and standards on lands within the boundaries of these reservations in order to avoid a gap in the classifications and standards adopted for the river basins in question. EPA has granted the Southern Ute and Ute Mountain Ute Indian tribes' applications for treatment as a state with respect to adoption of water quality standards. The Commission intends that the classifications and standards that it is adopting apply to the lands in question only to the extent that the state has jurisdiction and is not attempting to resolve that jurisdictional issue here. Segments within Reservation boundaries are noted in the segment description and Appendix 34-1 tables.

(5) Nutrients

Prior to May 31, 2022, interim nutrient values will be considered for adoption only in the limited circumstances defined at 31.17(e). These circumstances include headwaters, Direct Use Water Supply (DUWS) Lakes and Reservoirs, and other special circumstances determined by the Commission. Additionally, prior to May 31, 2017, only total phosphorus and chlorophyll a will be considered for adoption. After May 31, 2017, total nitrogen will be considered for adoption per the circumstances outlined in 31.17(e).

Prior to May 31, 2022, nutrient criteria will be adopted for headwaters on a segment by segment basis for the San Juan River Basin. Moreover, pursuant to 31.17(e) nutrient standards will only be adopted for waters upstream of all permitted domestic wastewater treatment facilities discharging prior to May 31, 2012 or with preliminary effluent limits requested prior to May 31, 2012, and any non-domestic facilities subject to Regulation 85 effluent limits and discharging prior to May 31, 2012. The following is a list of all permitted domestic wastewater treatment facilities discharging prior to May 31, 2012 or with preliminary effluent limits requested prior to May 31, 2012, and any non-domestic facilities subject to Regulation 85 effluent limits and discharging prior to May 31, 2012 in the San Juan River Basin:

Segment

Permittee

Facility name

Permit No.

COSJSJ05

San Juan River Village Metro

San Juan River Village Metro WWTF

COG588013

COSJSJ06a

High Country Lodge LLC

High Country Lodge

COG588002

COSJSJ06b

Pagosa Springs Sanitation District

Pagosa Springs San District WWTF

CO0022845

COSJPI06d

Pagosa Area Water and San Dist

Vista WWTF

CO0031755

COSJPN02a

Bayfield Town of

Bayfield Town of

CO0048291

COSJPN02a

Five Branches Camper Park

Five Branches Camper Park

COG588054

COSJPN02a

Forest Lake Metro Dist

Forest Lakes Metro District

CO0048160

COSJPN02a

Pine River Camp LLC

Kanakuk Colorado Youth Camp

COG588059

COSJPN04

Lipslea Enterprises LLC

Vallecito Resort

COG588026

COSJAF03b

Silverton Town of

Silverton Town of WWTF

CO0020311

COSJAF04b

Herrick Durango Land Co LLC

Durango North Ponderosa KOA

COG588020

COSJAF05a

Hermosa Sanitation District

Hermosa Sanitation District

COG588010

COSJAF05a

Durango City of

Durango City of

CO0024082

COSJAF05a

South Durango Sanitation District

South Durango SD WWTF

COG588057

COSJAF10a

Edgemont Ranch Metro Dist

Edgemont Ranch Metro District WWTF

CO0040266

COSJAF10b

Forest Groves Estates

Forest Groves Estates WWTP

COG588030

COSJAF11b

Durango La Plata County Airport

Durango/La Plata County Airport

CO0047457

COSJAF12a

Grizzly Peak Water Sales&Distribution LLC

Cascade Village WWTF

CO0039691

COSJAF12a

Purgatory Metropolitan District

Purgatory Metropolitan Dist

COG589010

COSJAF13c

Durango West Metro Dist #2

Durango West Metro Dist #2 WWTF

COG589115

COSJAF13d

Narrow Gauge MHP

Narrow Gauge MHP

COG589077

COSJAF14b

MacArthur Apartments LLC

Lightner Creek Campground

CO0026468

COSJLP05

Mancos Town of

Mancos Town of

CO0021687

COSJLP05

Upper Valley Sanitation

Upper Valley Sanitation Dist.

CO0047147

COSJLP07a

Cortez Sanitation District

Southwest WWTF

CO0027545

COSJLP07a

Vista Verde Village LLC

Vista Verde Village

CO0037702

COSJLP08

Elegant Hills Park and Estates LLC

Lakeside WWTF

COG589098

COSJLP09

Lee Mobile Home Park

Lee Mobile Home Park

COG589070

COSJLP10

Dove Creek Town of

Dove Creek WWTF

COG589079

COSJDO04a

Fort Beyhan LLC

Dolores River RV Park and Cabins

COG588071

COSJDO04a

Dolores Town of

Dolores WWTF

CO0040509

Prior to May 31, 2022:

* For segments located entirely above these facilities, nutrient standards apply to the entire segment.

* For segments with portions downstream of these facilities, nutrient standards only apply above these facilities. A note was added to the total phosphorus and chlorophyll a standards in these segments. The note references the table of qualified facilities at 34.5(5).

* For segments located entirely below these facilities, nutrient standards do not apply.

A note was added to the total phosphorus and chlorophyll a standards in lakes segments as nutrients standards apply only to lakes and reservoirs larger than 25 acres surface area.

Disclaimer: These regulations may not be the most recent version. Colorado may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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