5 Colo. Code Regs. § 1002-37.6
The numeric standards for various parameters in this regulation and in the tables in Appendix 37-1 were assigned by the Commission after a careful analysis of the data presented on actual stream conditions and on actual and potential water uses. For each parameter listed in the tables in Appendix 37-1, only the most stringent standard is shown. Additional, less stringent standards may apply to protect additional uses and can be found in the tables in Regulation No. 31.
Numeric standards are not assigned for all parameters listed in the tables in Regulation No. 31. If additional numeric standards are found to be needed during future periodic reviews, they can be assigned by following the proper hearing procedures.
ac | = | acute (1-day) |
°C | = | degrees Celsius |
ch | = | chronic (30-day) |
CL | = | cold lake temperature tier |
CLL | = | cold large lake temperature tier |
CS-I | = | cold stream temperature tier one |
CS-II | = | cold stream temperature tier two |
D.O. | = | dissolved oxygen |
DM | = | daily maximum temperature |
DUWS | = | direct use water supply |
E. coli | = | Escherichia coli |
mg/L | = | milligrams per liter |
MWAT | = | maximum weekly average temperature |
OW | = | outstanding waters |
sc | = | sculpin |
sp | = | spawning |
SSE | = | site-specific equation |
T | = | total recoverable |
t | = | total |
tr | = | trout |
TVS | = | table value standard |
µg/L | = | micrograms per liter |
UP | = | use-protected |
WL | = | warm lake temperature tier |
WS | = | water supply |
WS-I | = | warm stream temperature tier one |
WS-II | = | warm stream temperature tier two |
WS-III | = | warm stream temperature tier three |
Iron (chronic) | = | WS |
Manganese (chronic) | = | WS |
Sulfate (chronic) | = | WS |
These abbreviations mean: For all surface waters with an actual water supply use, the less restrictive of the following two options shall apply as numerical chronic standards, as specified in the Basic Standards and Methodologies at 31.16 Table II and III:
Manganese = 50 µg/L (dissolved)
Sulfate = 250 mg/L (dissolved)
For all surface waters with a "water supply" classification that are not in actual use as a water supply, no water supply standards are applied for iron, manganese or sulfate, unless the Commission determines as the result of a site-specific rulemaking hearing that such standards are appropriate.
In certain instances in the tables in Appendix 37-1, the designation "TVS" is used to indicate that for a particular parameter a "table value standard" has been adopted. This designation refers to numerical criteria set forth in the Basic Standards and Methodologies for Surface Water. The criteria for which the TVS are applicable are on the following table.
TABLE VALUE STANDARDS
(Concentrations in µg/L unless noted)
TABLE VALUE STANDARDS - FOOTNOTES
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Corral Gulch, Se(ch)=5.7 µg/L
Assessment location: Corral Gulch at the mouth.
Duck Creek, Se(ch)=7.9 µg/L
Assessment location: Duck Creek at the mouth.
Yellow Creek, Se(ch)=6.9 µg/L
Assessment location: Yellow Creek upstream from the confluence with Barcus Creek.
Greasewood Creek, Se(ch)=6.0 µg/L
Assessment location: Greasewood Creek at the mouth.
Yellow Creek, Fe(ch)=1625 µg/L
Assessment location: Yellow Creek at the mouth.
Unnamed tributary, Iron (chronic) = 3500 (T) µg/L, assessment location as follows:
* UT-2: Unnamed tributary, immediately downstream of the Tri-State Rifle Station discharge (39.519572, -107.729424)
Dry Creek and remaining tributaries and wetlands, Iron (chronic) = 5900 (T) µg/L, assessment location as follows:
* DC-2: Dry Creek, downstream of dry tributary channel entering from the east from the Garfield County Airport (39.523944, -107.73496)
Lower Colorado River from the confluence with the Roaring Fork River to Elk Creek
DM = 21.2 and MWAT = 16.9 from 4/1 - 5/31
DM and MWAT = CS-II from 6/1 - 9/30
DM = 21.2 and MWAT = 16.9 from 10/1 - 10/31
DM and MWAT = CS-II from 11/1 - 3/31
All other locations DM and MWAT = CS-II
Iron Standards:
* Collom Gulch from the source to the diversion structure at 40.333977, -107.860833:
March-May, Iron(chronic) = 1500 µg/L, median of all data
June-February, Iron(chronic) = 1000(T)
Iron Assessment Location:
* Collom Gulch at County Road 32: located at 40.323530, -107.877200
The stream classifications and water quality standards tables in Appendix 37-1 are incorporated herein by reference.
The following is information regarding duration and measured form of standards in Appendix 37-1:
5 CCR 1002-37.6