5 Colo. Code Regs. § 1002-37.5
All waters of the Colorado 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.
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 Appendix 37-1. The column in the tables at 31.11 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 37-1.
Prior to December 31, 2022 for chlorophyll a and prior to December 31, 2027 for total phosphorus, interim nutrient values will be considered for adoption only in the limited circumstances defined at 31.17(e) and (f). These circumstances include headwaters. Direct Use Water Supply (DUWS) Lakes and Reservoirs, and other special circumstances determined by the Commission. Additionally, prior to December 31, 2027, only total phosphorus and chlorophyll a will be considered for adoption. After December 31, 2027, total nitrogen will be considered for adoption per the circumstances outlined in 31.17(g).
Prior to December 31, 2027, nutrient criteria will be adopted for headwaters on a segment by segment basis for the Lower Colorado 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 Lower Colorado Basin:
Segment | Permittee | Facility name | Permit No. |
COLCLY02 | Craig City of | Craig WWTF | CO0040037 |
COLCWH07 | Whiteriver RV LLC | Whiteriver RV Sanitation WWTF | COG588048 |
COLCWH07 | Meeker Sanitation District | Meeker Sanitation District | CO0047139 |
COLCWmSb | Shell Frontier Oil & Gas Inc | Corral Gulch WWTF | CO0048859 |
C0LCWH21 | Rangely Town of | Rangely WWTF | CO0000010 |
COLCLC01 | Rifle City of | Rifle Regional WW Reclamation Facility | CO0048151 |
COLCLC01 | Wastewater Treatment Service LLC | Waste Water Treatment Services WWTF | COG589110 |
COLCLC01 | Silt Town of | Silt Town of | COG588046 |
COLCLC01 | West Glenwood Springs SD | West Glenwood Springs SD | COG588008 |
COLCLC01 | Glenwood Springs City of | Glenwood Springs Regional WWTF | CO0048852 |
COLCLC01 | Talbott Enterprises Inc | Talbott Enterprises Inc | COG588061 |
COLCLC01 | New Castle Town of | New Castle WWTF | COG588062 |
COLCLC01 | Riverbend Water and Sewer Company | Riverbend Subdivision | COG588006 |
COLCLC02a | Colorado Retail Ventures Services LLC | Cameo Eagle Travel Center | CO0048847 |
COLCLC02a | DeBeque Town of | DeBeque Town of | CO0048135 |
COLCLC02a | Battlement Mesa Metro Dist | Battlement Mesa Metro Dist WWTF | COG589086 |
COLCLC02b | Clifton Sanitation District | Clifton Sanitation District | CO0033791 |
COLCLC02b | Palisade Town of | Palisade WWTF | CO0000012 |
COLCLC03 | Fruita City of | Fruita Wastewater Reclamation Facility | CO0048854 |
COLCLC04e | Tri-State Generation & Transmission Assoc Inc | Rifle Station | CO0042447 |
COLCLC07a | Weiss & Associates | Canyon Creek Estates WWTF | COG589139 |
C0LCLC13b | Mesa Co/Grand Junction City of | Persigo WWTF | CO0040053 |
C0LCLC15a | Grand Mesa Metro Dist 2 | Grand Mesa Metro Dist 2 | CO0023485 |
C0LCLC15a | Mesa WSD | Mesa WSD | CO0048143 |
C0LCLC16 | Collbran Town of | Valleywide Sewerage System | CO0040487 |
Prior to December 31, 2027:
* 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 37.5(4).
* 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.
5 CCR 1002-37.5