5 Colo. Code Regs. § 1002-35-1
Effective 12/31/2023
Abbreviations and Acronyms
Aq | = Aquatic |
°C | = degrees Celsius |
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 |
EQ | = existing quality |
mg/L | = milligrams per liter |
mg/m2 | = milligrams per square meter |
mL | = milliliter |
MWAT | = maximum weekly average temperature |
OW | = outstanding waters |
sc | = sculpin |
SSE | = site-specific equation |
T | = total recoverable |
t | = total |
tr | = trout |
TVS | = table value standard |
µg/L | = micrograms per liter |
UP | = use-protected |
WS | = water supply |
WS-I | = warm stream temperature tier one |
WS-II | = warm stream temperature tier two |
WS-III | = warm stream temperature tier three |
WL | = warm lake temperature tier |
REGULATION #35 STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS
Upper Gunnison River Basin
REGULATION #35 STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS
North Fork of the Gunnison River Basin
REGULATION #35 STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS
Uncompahgre River Basin
REGULATION #35 STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS
Lower Gunnison Basin
REGULATION #35 STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS
San Miguel River Basin
REGULATION #35 STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS
Lower Dolores River Basin
All metals are dissolved unless otherwise noted.
T = total recoverable
t = total
tr = trout
sc = sculpin
D.O. = dissolved oxygen
DM = daily maximum
MWAT = maximum weekly average temperature
See 35.6 for further details on applied standards.
STREAM CLASSIFICATIONS and WATER QUALITY STANDARDS - FOOTNOTES
(A) Whenever a range of standards is listed and referenced to tinis footnote, tine first number in tine 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.
(B) Reserved.
(C) For certain site-specific temperature standards, the temperature excursions listed in Table I -Footnote 5(c) of 31.16 do not apply. Assessment of ambient-based temperature standards should be conducted in a way that represents similar conditions to those under which the criteria were developed (i.e., air, low flow, and warming event excursions should not apply). Similarly, where site-specific adjustments to the winter shoulder season have been adopted, the winter shoulder season excursion does not apply.
5 CCR 1002-35-1