DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT
WATER QUALITY CONTROL COMMISSION
5 CCR 1002-93
REGULATION #93 
Colorado's Section 303(d) List of Impaired Waters and Monitoring and Evaluation List
93.1	Authority
These regulations are promulgated pursuant to section 25-8-101 et seq C.R.S. as amended, and in particular, 25-8-202 (1) (a), (b), (i), (2) and (6); 25-8-203 and 25-8-204.
93.2	Purpose
This regulation establishes Colorado’s List of Water-Quality-Limited Segments Requiring Total Maximum Daily Loads (“TMDLs”) and Colorado’s Monitoring and Evaluation List.  
(1)	The list of Water-Quality-Limited Segments Requiring TMDLs fulfills requirements of section 303(d) of the federal Clean Water Act which requires that states submit to the U.S. Environmental Protection Agency a list of those waters for which technology-based effluent limitations and other required controls are not stringent enough to implement water quality standards.
(2)	Colorado’s Monitoring and Evaluation List identifies water bodies where there is reason to suspect water quality problems, but there is also uncertainty regarding one or more factors, such as the representative nature of the data.  Water bodies that are impaired, but it is unclear whether the cause of impairment is attributable to pollutants as opposed to pollution, are also placed on the Monitoring and Evaluation List.  This Monitoring and Evaluation list is a state-only document that is not subject to EPA approval.
93.3	Water Bodies Requiring TMDLs or Identified for Monitoring and Evaluation 
Only those segments where a Clean Water Section 303(d) Impairment has been determined require TMDLs.  For these segments, TMDLs are only required for those parameters that are identified as impairments.  Listings marked with an asterisk (*) are carryover from the 1998 303(d) List.  Consequently they are all high priority. 

WBID	Segment Description	Portion	Colorado’s Monitoring & Evaluation Parameter(s)	Clean Water Act Section 303(d) Impairment	303(d) Priority	
COAR	Arkansas River Basin	 		 	 	
COARFO01a	Fountain Creek and tributaries above Monument Creek	all		E. coli	H	
COARFO02a	Fountain Creek, Monument Creek to Hwy 47	all	Fe(Trec)	E. coli	H	
COARFO02b	Fountain Creek from Hwy 47 to the Arkansas River	all		E.coli (May-October)	H	
COARFO04	All tribs to Fountain Creek, which are not on National Forest or Air Force Academy Land	all		E.coli	H	
COARFO04	All tribs to Fountain Creek, which are not on National Forest or Air Force Academy Land	Sand Creek	Aquatic Life			
COARFO06	Monument Creek from National Forest to Fountain Creek	All (for E. coli)		E.coli (May-October)	H	
COARFO07a	Pikeview Reservoir, Willow Springs Ponds #1 and #2	Willow Springs Ponds #1 & #2		Aquatic Life Use (PCE FCA)	M	
COARLA01a	Arkansas River, Fountain Creek to Colorado Canal headgate	all		Se, SO4	L	
COARLA01b	Arkansas River, Colorado Canal headgate to John Martin Reservoir	all		 Se	L	
COARLA01c	Arkansas River, John Martin Reservoir to stateline	all		Se, U	L	
COARLA04	Apishapa River, Timpas Creek, Lorencito Canyon	Apishapa River, Timpas Creek		Se	L	
COARLA04	Apishapa River, Timpas Creek, Lorencito Canyon	Timpas Creek		Fe(Trec)	H	
COARLA05b	Trinidad Reservoir, Long Canyon Reservoir, and Lake Dorothey	Trinidad Reservoir	
 	Aquatic Life Use (Hg Fish Tissue), D.O. (Temperature)	H	
COARLA07	Purgatoire River, I-25 to Arkansas River	all	Sediment	Se	L	
COARLA09a	Mainstem of Adobe Creek and Gageby Creek…	all		Se	L	
COARLA09a	Mainstem of Adobe Creek and Gageby Creek…	Horse Creek		Fe(Trec)	H	
COARLA09a	Mainstem of Adobe Creek and Gageby Creek…	Adobe Creek		E. coli	H	
COARLA09b	Apache Creek, Breckenridge Creek, Little Horse Creek, Bob Creek, Wildhorse Creek, Wolf Creek, Big Sandy Creek	all		Se	L	
COARLA09c	Rule Creek, Muddy Creek, Caddoa Creek, Clay Creek, Cat Creek…	As specified to right	Zn
(Rule Creek)	Fe(Trec), Se
(Chicosa Creek)	L	
COARLA10	Two Buttes Res., Two Buttes Pond, Hasty Lake, Holbrook Res., Burchfield Lake, Nee-Skah (Queens) Res., Adobe Creek Res., Neeso Pah Res., Nee Nosha Res., Nee Gronda Res.	Adobe Creek Res., Nee Gronda Res		Se	L	
COARLA11	John Martin Reservoir	all		Se	L	
COARLA12	Lake Henry, Lake Meredith	all		Se	L	
COARMA04a	Wildhorse Creek	all	NO2	E. coli, Se	H/L	
COARMA06	St. Charles River and tributaries, CF&I diversion to Arkansas River	all	U	Se	L	
COARMA07	Greenhorn Creek, including all tributiaries, from source to Greenhorn Highline Diversion Dam; Graneros Creek; North Muddy Creek	all	Cu, Zn			
COARMA09	Greenhorn Creek, including tributaries, from Greenhorn Highline Diversion Dam to the St. Charles River	all	Se			
COARMA10	Sixmile Creek	all		Fe(Trec), Se	L	
COARMA12	Huerfano River, from Muddy Creek to the Arkansas River	all		Se	L	
COARMA14	Cucharas River, from Walsenburg PWS diversion to the outlet of Cucharas Reservoir	all	
	Se	L	
COARMA16	Huajatolla Reservoir, Diagre Reservoir, Walsenburg Lower Town Lake, Horseshoe Lake and Martin Lake (Ohem Lake)	Horseshoe Lake		Aquatic Life Use (Hg Fish Tissue)	H	
COARMA18a	Boggs Creek	all		Se, Zn, U	H	
COARUA05	All tributaries to the Arkansas River from the source to immediately below the confluence with Browns Creek 	Lake Fork below Sugarloaf Dam to the confluence with the Arkansas River	Aquatic Life 			
COARUA08b	Iowa Gulch from ASARCO water supply intake to Paddock #1 Ditch (Iowa Ditch)	all		Cd, Pb, Zn	M	
COARUA10	Mainstem of Lake Creek and all tributaries, lakes and reservoirs from source to Arkansas River (including Twin Lakes Reservoir)	all, excluding Twin Lakes Reservoir		pH, D.O.	H	
COARUA10	Mainstem of Lake Creek and all tributaries, lakes and reservoirs from source to Arkansas River (including Twin Lakes Reservoir)	Twin Lake West	
	Cu	H	
COARUA14b	Tributaries to the Arkansas River, from Pueblo Reservoir to Colorado Canal headgate	Teller Reservoir	Aquatic Life Use (Hg Fish Tissue)			
COARUA15	Grape Creek including De Weese Res., Texas, Badger, Hayden, Hamilton, Stout and Big Cottonwood Creeks, Newland Creek	De Weese Reservoir		D.O.	H	
COARUA20	Fourmile Creek and tributaries, Cripple Creek to Arkansas River	North Fork Wilson Creek below Independence Mine		As		
COARUA21a	Mainstem of Cripple Creek from the source to a point 1.5 miles upstream of the confluence with Fourmile Creek.	all		Aquatic Life (provisional)	L	
COARUA27	Mainstem of Eightmile Creek, including all tributaries, wetlands, lake and reservoirs, from the source to the mouth of Phantom  Canyon; Brush Hollow Reservoir	Brush Hollow Reservoir	

	Aquatic Life Use (Hg Fish Tissue), D.O.	H	
COGU	Gunnison River Basin	 		 	 	
COGULG02	Gunnison River, Uncompahgre River to Colorado River	all	Sediment	E. coli	H	
COGULG03	All tributaries to the Gunnison River which are on national forest lands from the outlet of Crystal Reservoir to the confluence with the Colorado River, 	Eggleston Reservoir	pH, Zn, 	Fe(Trec)	H	
COGULG04a	Tributaries to Gunnison River, Crystal Reservoir to Colorado River	Callow Creek	SO4, E. coli			
COGULG04a	Tributaries to Gunnison River, Crystal Reservoir to Colorado River	Cummings Gulch	SO4			
COGULG04a	Tributaries to Gunnison River, Crystal Reservoir to Colorado River	Whitewater Creekfrom below Brandon Ditch to confluence with Gunnison River		SO4, Mn (WS)	L	
COGULG04a	Tributaries to Gunnison River, Crystal Reservoir to Colorado River	Wells Gulch	pH			
COGULG04a	Tributaries to Gunnison River, Crystal Reservoir to Colorado River	Peach Valley Creek	Fe(Trec), SO4			
COGULG04b	All lakes and reservoirs tributary to the Gunnison River and not on national forest lands from the outlet of Crystal Reservoir to the Colorado River	Kannah Creek	SO4			
COGULG04b	All lakes and reservoirs tributary to the Gunnison River and not on national forest lands from the outlet of Crystal Reservoir to the Colorado River	Jatz Bottomlands	Se			
COGULG07	Surface, Ward, Tongue, Youngs, and Kiser Creeks not on USFS land	Tongue Creek		Se, Fe(Trec)	M	
COGULG07	Surface, Ward, Tongue, Youngs, and Kiser Creeks not on USFS land	Ward Creek	Se			
COGULG07	Surface, Ward, Tongue, Youngs, and Kiser Creeks not on USFS land	Surface Creek	Pb			
COGULG09	Fruitgrowers Reservoir	all		D.O.	H	
COGULG11a	Tributaries to the Smith Fork	Lunch Creek	sediment			
COGULG12	All tributaries to the Smith Fork which are not on national forest lands	Muddy Creek	E. coli			
COGULG13	Crawford Reservoir	all		D.O. (Temperature)	H	
COGUNF04	All tributaries to the North Fork of the Gunnison River Muddy Creek to Coal Creek; all tributaries to the North Fork of the Gunnison including the Grand Mesa Lakes which are on national forest lands	East Muddy Creek	Pb, Se	Fe(Trec)	H	
COGUNF04	All tributaries to the North Fork of the Gunnison River Muddy Creek to Coal Creek; all tributaries to the North Fork of the Gunnison including the Grand Mesa Lakes which are on national forest lands	Muddy Creek	E. coli (May-Oct)			
COGUNF04	All tributaries to the North Fork of the Gunnison River Muddy Creek to Coal Creek; all tributaries to the North Fork of the Gunnison including the Grand Mesa Lakes which are on national forest lands	Island Reservoir	pH, Zn			
COGUNF06a	Tributaries to N. Fork of Gunnison River not on USFS property	Unnamed tributary to North Fork Gunnsion River near Hotchkiss 	Se			
COGUNF06a	Tributaries to the North Fork of the Gunnison not on USFS lands	Coal Gulch, Hawksnest Creek, Gribble Gulch	Fe(Trec)			
COGUNF06b	Bear Creek, Reynolds Creek, Bell Creek, McDonald Creek, Cottonwood Creek, Love Gulch, Cow Creek, Dever Creek, German Creek, Miller Creek, Stevens Gulch, Big Gulch, Stingley Gulch and Alum Gulch not on national forest lands from the source to the North Fork of the Gunnison River	Cottonwood Creek	Fe(Trec), Mn(WS), SO4			
COGUNF06b	Bear Creek, Reynolds Creek, Bell Creek, McDonald Creek, Cottonwood Creek, Love Gulch, Cow Creek, Dever Creek, German Creek, Miller Creek, Stevens Gulch, Big Gulch, Stingley Gulch and Alum Gulch not on national forest lands from the source to the North Fork of the Gunnison River	Alum Gulch	Fe(Trec)	SO4	M	
COGUNF07	Paonia Reservoir	all	Zn			
COGUSM02	Tributaries to the San Miguel River from the source to Leopard Creek	Bear Creek	Pb	Cd, Zn(sc)	H	
COGUSM02	Tributaries to the San Miguel River from the source to Leopard Creek	Cornet Creek	Pb			
COGUSM02	Tributaries to the San Miguel River from the source to Leopard Creek	Howard Fork above Swamp Canyon	 	pH, D.O.	H	
COGUSM03b	Mainstem of the San Miguel River Marshall Creek to South Fork San Miguel River.	all	Pb			
COGUSM04a	Mainstem of the San Miguel River from the South Fork of the San Miguel to below the CC ditch.	From South Fork San Miguel to confluence with Leopard Creek	Pb			
COGUSM06a	Ingram Creek, source to San Miguel River	all	Mn, Cu			
COGUSM06b	Marshall Creek, source to San Miguel River	all	Cu			
COGUSM07a	Mainstem of Howard Fork and tributaries Swamp Gulch the South Fork of the San Miguel.	Chapman Creek	Fe(Trec)			
COGUSM07a	Mainstem of Howard Fork and tributaries Swamp Gulch the South Fork of the San Miguel.	Iron Bog Creek	pH, D.O.			
COGUSM08	Mainstem of South Fork of San Miguel River from the Howard and Lake Forks to the San Miguel River.	all	Mn(WS)			
COGUSM10	Mainstem of Naturita Creek from the Uncompahgre National Forest boundary to its confluence with the San Miguel River, and Gurley Reservoir; Tabeguache Creek from its source to the confluence with San Miguel River.	Naturita Creek	D.O., E. coli			
COGUSM11	West Fork of Naturita Creek, Miramonte Reservoir, the mainstem of Beaver, Horsefly and Saltado Creeks from the Uncompahgre National Forest boundary to their confluence with the San Miguel River.	Miramonte Reservoir		D.O. (Temperature)	H	
COGUSM12	All tributaries to the San Miguel River from the confluence of Leopard Creek to the Dolores 	Mesa Creek	Se			
COGUSM12	All tributaries to the San Miguel River from the confluence of Leopard Creek to the Dolores 	Calamity Draw, Specie Creek	D.O.			
COGUSM12	All tributaries to the San Miguel River from the confluence of Leopard Creek to the Dolores 	Maverick Draw 		Aquatic Life (provisional)	L	
COGUUG04	Mainstem of the Taylor River from the source to the confluence with the Gunnison River 	Taylor River	Pb			
COGUUG06b	Cement Creek and all its tributaries and all lakes, reservoirs, and wetlands in the East River Drainage tributary to Segment 6a.	Cement Creek		Aquatic Life (provisional)	L	
COGUUG07	Slate River from source to Coal Creek	Below Oh-Be-Joyful Creek		Zn(sculpin)	H	
COGUUG08	Slate River, Coal Creek to East River 	all	Aquatic Life	Cd, Zn	H	
COGUUG09	All tributaries to the Slate River 	Coal Creek		As	H	
COGUUG10	Oh-Be-Joyful Creek and tributaries from wilderness to Slate River	all		Cd, Cu, Pb, Zn	H	
COGUUG10	Oh-Be-Joyful Creek and tributaries from wilderness to Slate River	Redwell Creek	pH			
COGUUG11	Coal Creek from Elk Creek to Crested Butte water supply intake, plus Elk Creek	Elk Creek		Cd, Pb, Zn, As	H	
COGUUG11	Coal Creek from Elk Creek to Crested Butte water supply intake, plus Elk Creek	Coal Creek		Cd, Zn, As, Mn(WS)	H	
COGUUG12	Coal Creek and tributaries from Crested Butte water supply intake to Slate River	Coal Creek		Cd, Zn, Cu	H	
COGUUG15	Tributaries to the Gunnison River from the confluence of the East and Taylor Rivers to the inlet of Blue Mesa Reservoir 	S. Beaver Creek	Mn (WS), Fe (Dis), Fe(Trec), 	Aquatic Life (provisional)	L	
COGUUG16	Ohio Creek and tributaries source to Gunnison River	Ohio Creek	E. coli			
COGUUG17	Antelope Creek and tributaries source to Gunnison River	all	Mn (WS), E. coli			
COGUUG23	Mainstem of Cochetopa Creek and tributaries, from the source to a point immediately below the confluence with West Pass Creek 	Stewart Creek	Fe(Trec)			
COGUUG23	Mainstem of Cochetopa Creek and tributaries, from the source to a point immediately below the confluence with West Pass Creek 	Cochetopa Creek	Fe(Dis)			
COGUUG24	Mainstem of Cochetopa Creek from West Pass Creek to Tomichi Creek	Cochetopa Creek from  Forest Road 3076/Co. Rd. 43 to the confluence with Tomichi Creek		Aquatic Life (provisional)	L	
COGUUG26	All tributaries, from the source, to those waters described in segment 25 including all lakes, reservoirs (including Silver Jack Reservoir), and wetlands, which are on Gunnison and Uncompahgre National Forest lands or which flow into or are present within Curecanti National Recreation Area 	Blue Creek	Cu			
COGUUG29a	Lake Fork of the Gunnison River and tributaries from source to Blue Mesa Reservoir	Deadman Creek 		pH, Cd, Cu, Mn, Zn, Se, Fe (Trec), Fe (Dis)	H	
COGUUG29a	Mainstem of the Lake Fork of the Gunnison and tributaries from the source to Blue Mesa Reservoir	Lake Fork of the Gunnison River between Cooper and Silver Creek		Mn (WS), Aquatic Life (provisional)	H	
COGUUG31	Palmetto Gulch	all	Cu, Ag			
COGUUG32	North Fork of Henson Creek and tributaries from source to Henson Creek	all		Mn (WS)	L	
COGUUN02	Mainstem of the Uncompahgre River from the source at Como Lake to a point immediately above the confluence with Red Mountain Creek.	all	Pb	Mn (WS)	L	
COGUUN03b	Ridgway Reservoir	all	Pb, Zn			
COGUUN04a	Uncompahgre River, HWY 90 to La Salle Road	all	sediment			
COGUUN04b	Uncompahgre River, La Salle Road to Confluence Park	all	sediment			
COGUUN04c	Uncompahgre River, Confluence Park to Gunnison River	all	Sediment, Pb	Fe(Trec)	H	
COGUUN06a	Mainstem of Red Mountain Creek from the source to immediately above the confluence with the East Fork of Red Mountain Creek.	all		Ag, Cu	M	
COGUUN07	Gray Copper Gulch from source to Red Mountain Creek	all	Fe(Trec), pH	Cu	M	
COGUUN08	Mineral Creek, source to Uncompahgre River	all	Cu, Zn			
COGUUN09	Canyon Creek, Imogene Creek, Sneffels Creek	Sneffels Creek		Cd, Zn	H	
COGUUN09	Canyon Creek, Imogene Creek, Sneffels Creek	Canyon Creek	Pb			
COGUUN10	All tributaries to the Uncompahgre River from Dexter Creek to the South Canal	Alkali Creek	Se			
COGUUN11	Coal, Dallas, Cow, Billy, Onion, Beaton, Beaver and Pleasant Valley Creeks	Billy Creek, Onion Creek	Se			
COGUUN11	Coal, Dallas, Cow, Billy, Onion, Beaton, Beaver and Pleasant Valley Creeks	Deer Creek		Aquatic Life (provisional)	L	
COGUUN11	Coal, Dallas, Cow, Billy, Onion, Beaton, Beaver and Pleasant Valley Creeks	Cow Creek	SO4			
COGUUN12	Tributaries to Uncompahgre River, South Canal to Gunnison River	Dry Creek, Loutzenhizer Arroyo		Fe(Trec)	H	
COGUUN14	Sweitzer Lake	all		Se*	H	
COGUUN15b	Dry Creek from East and West Forks to Coalbank Canyon Creek	Dry Creek Watershed	sediment			
COGULD02	Dolores River from Little Gypsum Valley bridge to Colorado/Utah border	all	E. coli	Fe(Trec)	H	
COGULD03a	All tributaries to the Dolores River from the bridge at Bradfield Ranch to the Colorado/Utah border.	Disappointment Creek	Se, E. coli			
COGULD04	Mainstem of West Paradox Creek from the source to the confluence with the Dolores River. Mainstem and all tributaries to Blue Creek from the source to the confluence with the Dolores River.	West Paradox Creek	E. coli, Fe(Trec)			
COGULD05	Mainstem of West Creek from the source to the confluence with the Dolores River; Roc Creek; La Sal Creek and Mesa Creek from their sources to their confluences with Dolores River.	Roc Creek	E. coli	Cu, Fe(Trec)	H	
COLC	Lower Colorado River Basin	 		 	 	
COLCLC01	Colorado River, Roaring Fork River to Rifle Creek	all	sediment			
COLCLC02a	Colorado River, Rifle Creek to Rapid Creek	all	sediment			
COLCLC02b	Colorado River, Rapid Creek to Gunnison River	Humphrey Backwater area 	
	Se	M	
COLCLC02b	Colorado River, Rapid Creek to Gunnison River	all 	
Sediment
			
COLCLC04a	Tributaries to Colorado River, Roaring Fork to Parachute Creek except for specific segments	all		Se	M	
COLCLC04a	Tributaries to Colorado River, Roaring Fork to Parachute Creek Exc. specific segments	Alkali Creek	E.coli, Cu, Fe(Trec), Pb, Zn			
COLCLC04b	South Canyon Hot Springs	all	D.O., Pb			
COLCLC04c	South Canyon Creek	all	Cu, Se, E. coli (May-Oct)			
COLCLC10	East Rifle Creek, West Rifle Creek and Rifle Creek, including tributaries from Rifle Gap to the Colorado River	West Rifle Creek	Fe(Trec)			
COLCLC10	East Rifle Creek, West Rifle Creek and Rifle Creek, including tributaries from Rifle Gap to the Colorado River	all	E.coli	Se	L	
COLCLC13b	Tributaries to Colorado River from Government Highline Canal Diversion to Salt Creek	Salt Creek		sediment	L	
COLCLC13b	Tributaries to Colorado River from Government Highline Canal Diversion to Salt Creek	all		Se	M	
COLCLC13b	Tributaries to Colorado River from Government Highline Canal Diversion to Salt Creek	Adobe Creek, Leach Creek 		E.coli, Fe(Trec)	H	
COLCLC13b	Tributaries to Colorado River, Government Highline Canal to Salt Creek Exc. specific segments	Indian Wash	Fe(Trec)			
COLCLC13c	Walker Wildlife Area Ponds	all		Se	M	
COLCLC14b	Clear Creek from Tom Creek to Roan Creek. Roan Creek, including tributaries from Clear Creek to Kimball Creek	all	E.coli, Fe(Trec)			
COLCLC14c	Mainstem of Roan Creek including all tributaries from Kimball Creek to the Colorado River	Dry Fork		Se	L	
COLCLC15	Plateau Creek, including tributaries from source to Hwy 330 Bridge.  Kimball Creek, Grove Creek, Big Creek, Cottonwood Creek, Bull Creek, Spring Creek, Coon Creek and Mesa Creek.	all	Fe(Trec), Se			
COLCLC19	Lakes and reservoirs tributary to the Colorado River, Parachute Creek to the Colorado/Utah border.	See specifics to the right.	
Se 
(Maggio Pond, Peters Ponds 1, 2, 3, & 4)	Se 
(West Pond Orchard Mesa Wildlife Area)	H	
COLCLC20	Rifle Gap Reservoir, Harvey Gap Reservoir and Vega Reservoir	Rifle Gap Reservoir		Aquatic Life Use (Hg Fish Tissue)	H	
COLCLY02	Yampa River, Elkhead Creek to Green River	all	sediment	Fe(Trec)	H	
COLCLY03c	Milk Creek and tributaries from CR 15 to the Yampa	Stinking Gulch	Cu, Fe(Trec), Se, Zn			
COLCLY03e	Good Spring Creek above Wilson Reservoir	Wilson Creek	Se			
COLCLY05	Fortification Creek from North and South Fork to the Yampa River	all		Se	L	
COLCLY07	Little Bear Creek, including all tributaries from source to Dry Creek	all	Cu, Zn			
COLCLY16	Little Snake River from Power Wash to the Yampa River	all	sediment			
COLCLY18	Slater Creek, including tributaries from source to Second Creek	all	E. coli, Fe (Trec),Se			
COLCLY22a	Mainstem of Vermillion Creek, including all tributaries and wetlands, from the Colorado/Wyoming border to a point just below the confluence with Talamantes Creek.	Talamantes Creek		Aquatic Life (provisional)	 L	
COLCLY22c	Vermillion Creek from Hwy 318 to Green River	all	E.coli, Fe(Trec)			
COLCWH07	Mainstem of the White River from a point above the confluence with Miller Creek to a point immediately above the confluence with Piceance Creek	White River, blw Meeker	Cu			
COLCWH09a	Tributaries to the White River from North and South Forks to Piceance Creek not within the boundary of national forest lands except segments 9b and 10b.	Strawberry Creek	Cu, Zn			
COLCWH09d	Sulfur Creek and tributaries from Source to White River. Flag Creek and tributaries from the East Fork of Flag Creek to the White River	all		Se	L	
COLCWH10b	Mainstem of Big Beaver Creek, Miller Creek, and North Elk Creek, including tributaries, from their boundaries with the national forest lands to their confluences with the White River.  Mainstem of Coal Creek, including all tributaries from the source to the confluence with the White River 	Coal Creek	Se			
COLCWH11	Rio Blanco Reservoir	Rio Blanco Reservoir		pH	H	
COLCWH13b	Mainstem of Yellow Creek from the source to the confluence with Barcus Creek. All tributaries to Yellow Creek from the source to the White River	Duck Creek	Aquatic Life			
COLCWH13c	Mainstem of Yellow Creek from immediately below the confluence with Barcus Creek to the confluence with the White River.	All		Fe (Trec), Aquatic Life	L	
COLCWH14a	Mainstem of Piceance Creek from the source to a point just below the confluence with Hunter Creek	Willow Creek to Hunter Creek		Fe(Trec)	H	
COLCWH15	Mainstem of Piceance Creek from Ryan Gulch to the confluence with the White River. The Dry Fork of Piceance Creek, from Little Reigan Gulch to Piceance Creek.	Piceance Creek		Aquatic Life (provisional)	L	
COLCWH16	All tributaries to Piceance Creek, including all wetlands, lakes and reservoirs, from the source to the confluence with the White River	Ryan Gulch	E.coli			
COLCWH20	Mainstems of Black Sulphur Creek from the source to Piceance Creek.	Black Sulphur Creek		Aquatic Life (provisional)	L	
COLCWH22	Tributaries to White River, Douglas Creek to Colorado/Utah border	West Evacuation Wash, Douglas Creek		sediment	L	
COLCWH23	Mainstem of East Douglas Creek and West Douglas Creek including all tributaries from their sources to the confluence	East Douglas Creek	Fe(Trec)			
COLCWH23	Mainstem of East Douglas Creek and West Douglas Creek including all tributaries from their sources to the confluence	West Douglas Creek		Aquatic Life (provisional)	L	
CORG	Rio Grande River Basin					
CORGAL02	Alamosa River, from source to confl with Alum Creek	Tribs to lower Iron Ck		pH, Cu, Zn, Fe(Trec)	H	
CORGAL02	Alamosa River, from source to confluence with Alum Creek	All, except for the tributaries to Lower Iron Creek	pH, Fe(Trec)			
CORGAL03b	Alamosa River, from Wightman Fork to Fern Creek	Above Jasper Creek	Se	Cd	H	
CORGAL03d	Alamosa River, from Ranger Creek to Terrace Res.	all		Al	H	
CORGAL08	Terrace Reservoir	all		Fe(Trec)	M	
CORGAL11	La Jara Creek including tributaries, wetlands, lakes and reservoirs from source to Hot Creek	La Jara Reservoir	
pH	D.O.	H	
CORGAL13	Hot Creek from source to La Jara Creek	all		Fe(Trec)	H	
CORGAL14	Conejos River including tributaries, wetlands, lakes, and reservoirs from source to Fox Creek	Platoro Reservoir	pH			
CORGAL20	Rio Grande, tribs within the Rio Grande Forest	all	pH, Cu,Cd, Fe(Trec), Mn, Zn			
CORGCB02	La Garita Creek, source to 38 Rd, Carnero Creek, source to 42 Rd	La Garita Creek	Fe(Trec)			
CORGCB05	San Luis Creek, from Piney Creek to San Luis Lake	Lower San Luis Creek	D.O.			
CORGCB06	San Luis Lake	all		NH3, Fe(Trec)	H	
CORGCB08	Kerber Creek, source to abv Cocomongo Mill Site, Squirrel Creek from source to abv Bear Creek. Brewery Creek from source to Elkhorn Gulch	Squirrel Creek	Cd, Cu, Zn, Fe(Trec)			
CORGRG02	Rio Grande River, source to Willow Creek	South Clear Creek	Fe(Trec), 			
CORGRG04	Rio Grande River, Willow Creek to Alamosa County line	Del Norte to county line		Cu	H	
CORGRG05	All tributaries to the Rio Grande River, abv Willow Creek to Del Norte	Nelson Creek	Cd, Cu, Pb, Mn, Zn, pH 			
CORGRG07	West Willow Creek, East Willow Creek, Willow Creek and tributaries	Nelson Creek, West Willow Creek below Nelson Creek to East Willow Creek	
	pH	H	
CORGRG12	Mainstem of the Rio Grande from the Rio Grande/Alamosa County line to the Old State Bridge east of Lobatos (Conejos County Road G).	all		Aquatic Life (provisional)	L	
CORGRG13	Rio Grande River, Conejos County Road G to Colorado/New Mexico border	all	sediment			
CORGRG27	Smith Reservoir	Smith Reservoir	pH			
CORGRG28	Rito Seco, from source to Salazar Reservoir	Upper Rito Seco blw Battle Mtn		E.coli	H	
CORGRG30	Culebra Creek, including all tributaries, lakes, and reservoirs from HWY 159 to the Colorado/New Mexico border	Sanchez Reservoir		D.O.	H	
COSJ	San Juan River Basin	 		 	 	
COSJAF03c	Arrastra Gulch including all lakes, tributaries, and wetlands from the source to the confluence with the Animas River.	all	Pb	Cd, Zn	M	
COSJAF04a	Mainstem of the Animas River from a point immediately above the confluence with Mineral Creek to a point immediately above the confluence with Deer Park Creek.	all		Al(Trec)	M	
COSJAF05a	Mainstem of the Animas River, including wetlands, from Bakers Bridge to the Southern Ute Indian Reservation boundary.	all		Mn(WS)	L	
COSJAF12a	All tributaries to the Animas River, from a point immediately above the confluence with Elk Cr. to a point immediately below the confluence with Hermosa Cr. All tributaries to the Florida from the source to the outlet of Lemon Reservoir Mainstems of True, Red and Shearer Creeks from their sources to their confluences with the Florida River.	Electra Reservoir	Ag, Zn			
COSJAF13a	Mainstem of Junction Creek including all tributaries, from U.S. Forest Boundary to confluence with Animas River.	Junction Creek	Ag, E. coli			
COSJDO04b	McPhee Reservoir and Summit Reservoir	McPhee Reservoir		Aquatic Life Use(Hg* Fish Tissue)	H	
COSJDO11	All tributaries to the Dolores River, from the confluence of the West Dolores River, to the bridge at Bradfield Ranch (Forest Route 505, near Montezuma/Dolores County Line	Lost Canyon Creek	E. coli			
COSJLP01	Mainstem of the La Plata River, from the source to the Hay Gulch diversion south of Hesperus.	All		Ag	H	
COSJLP03a	All Tributaries to the La Plata River from Hay Gulch to the Southern Ute Indian reservation boundary	Cherry Creek	Cu	Fe(Trec)	H	
COSJLP04a	Mancos River and tributaries above HWY 160	E. Mancos River	Pb	Cu,D.O., Mn (WS)	H	
COSJLP04a	Mancos River and tributaries above HWY 160	Mancos River	Cu, Pb	D.O.,	H	
COSJLP07a	Mainstem of McElmo Creek from the source to the Colorado/Utah border; Mainstem of Yellow Jacket Creek from the source to the confluence with McElmo Creek.	McElmo Creek		Fe-Trec, E. coli	H	
COSJLP08a	Tributaries to McElmo Creek	Mud Creek		Se	M	
COSJLP08a	Tributaries to McElmo Creek 	Hartman Draw	Fe(Trec)			
COSJLP08a	Tributaries to McElmo Creek 	Trail Canyon		Fe(Trec)	M	
COSJLP08a	Tributaries to McElmo Creek 	all	E. coli			
COSJLP11	Narraguinnep, Puett, and Totten Reservoir	Narraguinnep Reservoir, Totten Reservoir		Aquatic Life Use(Hg* Fish Tissue)	H	
COSJPI05	All tributaries to the Piedra River, including all wetlands, lakes and reservoirs, from the boundary of the Weminuche Wilderness Area to a point immediately below the confluence with Devil Creek. Williams Creek Reservoir.	Williams Creek Reservoir	pH, Zn, Fe(Trec), D.O.			
COSJPI05	All tributaries to the Piedra River, from the boundary of the Weminuche Wilderness Area to the confluence with Devil Creek. Williams Creek Reservoir.	Williams Creek	pH, Cu			
COSJPI06a	Tributaries to the Piedra River	Stollsteimer Creek above Southern Ute Boundary	Sediment, E. coli, Fe(Trec), SO4			
COSJPN03	Vallecito Reservoir	Vallecito Reservoir		Aquatic Life Use (Hg Fish Tissue)	H	
COSJSJ01	Mainstem of the Navajo River and the Little Navajo River from the boundary of the South San Juan Wilderness Area to the Colorado/New Mexico border	Navajo River	E. coli			
COSJSJ03	Little Navajo River, including tributaries from the San Juan-Chama diversion to the San Juan River	all	E.coli			
COSJSJ05	Mainstem of the San Juan River and the East Fork and West Fork of the San Juan River, from the boundary of the Weminuche Wilderness Area (West Fork) and the source (East Fork) to Fourmile Creek	Mainstem	Pb			
COSJSJ06a	San Juan River from Fourmile Creek to Southern Ute Indian Reservation.  Mill Creek from source to San Juan River.  Echo Canyon Reservoir.	San Juan River	Pb, Cu			
COSJSJ06a	San Juan River from Fourmile Creek to Southern Ute Indian Reservation.  Mill Creek from source to San Juan River.  Echo Canyon Reservoir.	Echo Canyon Reservoir	pH	D.O. (Temperature)
Aquatic Life Use (Hg Fish Tissue)	H	
COSJSJ08	Navajo Reservoir	Navajo Reservoir	Aquatic Life Use (Hg Fish Tissue)			
COSJSJ09a	Mainstem of the Rio Blanco from the boundary of South San Juan Wilderness Area to the Southern Ute Indian Reservation boundary, 		Ag, Pb			
COSJSJ10	Mainstem of the Rito Blanco River from Echo Ditch to the confluence with the Rio Blanco River.		E. coli			
COSP	South Platte River Basin	 		 	 	
COSPBD01	Mainstem of Big Dry Creek, including all tributaries, lakes, reservoirs and wetlands, from the source to the confluence with the South Platte River	all		E. coli, 
Se (4/1 thru 10/31)	H/L	
COSPBE01a	Mainstem of Bear Creek from the boundary of the Mt. Evans Wilderness area to the inlet of Evergreen Lake.	Witter Gulch to inlet of Evergreen Lake 		Temperature, Aquatic Life (provisional)	H 	
COSPBE01c	Bear Creek Reservoir	all		Chl-a, phosphorus	H	
COSPBE01e	Mainstem of Bear Creek from the outlet of Evergreen Lake to the Harriman Ditch.	All	Aquatic Life			
COSPBE01e	Mainstem of Bear Creek from the outlet of Evergreen Lake to the Harriman Ditch.	From the outlet of Evergreen Lake to Kerr/Swede Gulch		Temperature	H	
COSPBE02	Bear Creek below Bear Creek Reservoir to South Platte River	Below Kipling Parkway (CO 390)	Aquatic Life	E.coli (May-Oct)	H	
COSPBE05	Swede, Kerr, Sawmill, Troublesome and Cold Springs Gulches and Cub Creek	Swede/Kerr Gulch		E.coli	L	
COSPBO01	All tribs to Boulder Creek within the Indian Peaks Wilderness Area	all	Pb, Zn			
COSPBO02a	Mainstem of Boulder Creek,from the boundary of the Indian Peaks Wilderness Area to a point immediately below the confluence with North Boulder Creek	all	Cd, Cu			
COSPBO02b	Boulder Creek, from below the confluence with North Boulder Creek to above the confluence with South Boulder Creek	all	Cd, Cu			
COSPBO03	Mainstem of Middle Boulder Creek from source to the outlet of Barker Reservoir	all	Cd, Cu			
COSPBO07b	Coal Creek, HWY 36 to Boulder Creek	all	Aquatic Life	E. coli	H	
COSPBO08	All tribs to South Boulder Creek and all tribs to Coal Creek	Rock Creek	E. coli, 	Se	M	
COSPBO09	Mainstem of Boulder Creek, from South Boulder Creek to Coal Creek	all	Cd, As			
COSPBO09	Mainstem of Boulder Creek, from South Boulder Creek to Coal Creek	From 107th Street to the confluence with Coal Creek		Aquatic Life (provisional)	L	
COSPBO10	Boulder Creek, Coal Creek to St. Vrain Creek	all	Aquatic Life, Cd	E. coli	H	
COSPBO14	Lakes and reservoirs tributary to Boulder Creek from source to South Boulder Creek.	Barker Reservoir	Cd, Cu			
COSPBO15	South Boulder Creek and tributaries from source to outlet of Gross Reservoir	Gross Reservoir	Aquatic Life Use (Hg Fish Tissue)			
COSPBT01	Mainstem of the Big Thompson River, including all tributaries and wetlands, within Rocky Mountain National Park.	All		Cu	H	
COSPBT02	Big Thompson River and tribs, RMNP to Home Supply Canal diversion	Fish Creek below Marys Lake		pH	H	
COSPBT02	Big Thompson River and tribs, RMNP to Home Supply Canal diversion	all	Sulfide	Cu, Cd, Zn, temperature 	H	
COSPBT03	Mainstem of the Big Thompson River from the Home Supply Canal diversion to the Big Barnes Ditch diversion. 	

	All		Cu	M	
COSPBT04a	Mainstem of the Big Thompson from the Big Barnes Ditch diversion of the Greeley-Loveland Canal diversion.	All		 Se	M	
COSPBT04b	Big Thompson River, Greeley-Loveland Canal diversion to CR11H	all		Se	M	
COSPBT05	Big Thompson River, I-25 to S. Platte River	all		Se	L	
COSPBT06	All tributaries to the Big Thompson River, from Home Supply Canal to the confluence with the South Platte River.	All		Cu	M	
COSPBT06	All Tribs to the Big Thompson River, from Home Supply Canal to the confluence with the South Platte River.	Dry Creek	E. Coli			
COSPBT07	Mainstem of the North Fork of the Big Thompson from RMNP to confluence with Big Thompson	North Fork of Big Thompson		Cu	H	
COSPBT08	Mainstem of the Little Thompson River, from source to the Culver Ditch diversion.	All		Temperature, D.O	H	
COSPBT08	Mainstem of the Little Thompson River, from source to the Culver Ditch diversion.	From source to St. Vrain Supply Canal		SO4	H	
COSPBT09	Little Thompson River, Culver Ditch to Big Thompson River	all		Cu, Se, E. coli (May-October), Aquatic Life Use	M/L/H/M	
COSPBT10	Tributaries To the Little Thompson River	Big Hollow		Se	L	
COSPBT11	Carter Lake	all		Aquatic Life Use (Hg Fish Tissue), As	H	
COSPBT12	Lake Loveland, Horseshoe Lake, Boyd Lake	Boyd Lake		Aquatic Life Use (Hg Fish Tissue)	H	
COSPBT14	Welch Reservoir, Lonetree Reservoir, Boedecker Lake, Lon Hagler Reservoir	Lonetree Reservoir	Aquatic Life Use (Hg Fish Tissue)			
COSPBT16	Lakes and reservoirs tributary to the Big Thompson from RMNP to Home Supply Canal diversion.	Lake Estes		Cu, Pb	H	
COSPCH03	Mainstem of Cherry Creek from Cherry Creek Reservoir to the South Platte.	All		E.coli, Se	H/L	
COSPCH03	Mainstem of Cherry Creek from Cherry Creek Reservoir to the South Platte.	From Holly Street to South Platte confluence		Fe(Trec)	M	
COSPCH04	Tributaries to Cherry Creek 	Goldsmith Gulch, Cottonwood Creek		Se	L	
COSPCH06	Lakes and reservoirs in the Cherry Creek watershed within the City and County of Denver.	Lollipop Lake	Se	D.O.	M	
COSPCL01	Mainstem of Clear Creek, including all tributaries and wetlands, from the source to the I-70 bridge above Silver Plume.	Kearney Gulch, Grizzly Gulch	Aquatic Life			
COSPCL02a	Mainstem of Clear Creek from Silver Plume to West Fork Clear Creek.	All		Cd	H	
COSPCL02b	Mainstem of Clear Creek from West Fork Clear to Mill Creek.	All		Cd, Zn	H	
COSPCL02c	Mainstem of Clear Creek from Mill Creek to Argo Tunnel.	All		Cd	H	
COSPCL03a	Mainstem of S. Clear Creek	all		Cu	H	
COSPCL03b	Leavenworth Creek	all		Cu	M	
COSPCL06	West Clear Creek tributaries	Mad Creek	pH	Zn	M	
COSPCL06	All tributaries to West Clear Creek.	Hoop Creek	Cd, Pb, Zn			
COSPCL09a	Fall River & tributaries, source to Clear Creek	Fall River	Zn, D.O.			
COSPCL09a	Fall River & tributaries, source to Clear Creek	Silver Creek		Cu, Pb	H	
COSPCL09b	Trail Creek & tributaries, source to Clear Creek 	all		Cd, pH	H	
COSPCL11	Clear Creek, Argo Tunnel to Farmers Highline Canal	all		Cd	H	
COSPCL13b	N. Clear Creek & tributaries, lowest water supply intake to Clear Creek	Mainstem of N. Clear Creek		Cd	M	
COSPCL14a	Mainstem of Clear Creek from the Farmers Highline Canal diversion in Golden, Colorado to the Denver Water conduit #16 crossing.	From Croke Canal Diversion to McIntyre Street		Aquatic Life (provisional)	L	
COSPCL14b	Clear Creek, Denver Water conduit #16 to Youngfield St.	all	Mn	Aquatic Life Use, organic sediment, 	L	
COSPCL15	Clear Creek, Youngfield St. to S. Platte River	all	Pb	E. coli (May-October), Aquatic Life Use, organic sediment, Mn (WS)	H/L/L	
COSPCL17a	Arvada Reservoir	all		D.O.(Temperature)	H	
COSPCL17b	Mainstem of Ralston Creek, including all tributaries and wetlands, from the source to the inlet of Arvada Reservoir.	all		U	H	
COSPCL18a	Ralston Creek and tributaries below Arvada Reservoir	Ralston Creek		E. coli	H	
COSPCP06	Mainstem of the North Fork of the Cache La Poudre River, including all tribs from source to Halligan Res.	all	Cu			
COSPCP07	North Fork of the Cache la Poudre from Halligan Reservoir to the Cache la Poudre.	all		Pb, Cd	M	
COSPCP08	All tributaries to the North Fork of the Cache La Poudre from Halligan Reservoir to the Cache La Poudre.	all	E. coli			
COSPCP09	Rabbit Creek and Lone Pine Creek	all	Cd, Pb			
COSPCP10	Cache la Poudre River, Monroe Canal to Shields Street	all		Cu, Temperature	M	
COSPCP11	Mainstem of the Cache la Poudre River from Shields Street in Ft. Collins to a point immediately above the confluence with Boxelder Creek. 	

	all	

	Se	L	
COSPCP12	Cache la Poudre River, Box Elder Creek to S. Platte River	all		Se, E. coli (May-October)	L/H	
COSPCP13a	All tributaries to the Cache la Poudre River, including all wetlands, from the Monroe Gravity Canal to the confluence with the South Platte River.	all		Se	L	
COSPCP13a	All tributaries to the Cache la Poudre River, including all wetlands, from the Monroe Gravity Canal to the confluence with the South Platte River.	Spring Creek and Fossil Creek		E.coli, (May-Oct)	H	
COSPCP13b	Boxelder Creek from source to the Cache la Poudre River	all		Se	L	
COSPCP14	Horsetooth Reservoir	all	.	Aquatic Life Use (Hg Fish Tissue), Cu, As	H	
COSPCP20	Lakes and reservoirs tributary to the North Fork of the Cache la Poudre from Halligan Reservoir to the Cache la Poudre River.	Seaman Reservoir		D.O.	M	
COSPLA02a	Mainstem of Laramie River from the source to the NF boundary.	all	pH			
COSPLS01	Mainstem of the South Platte from the Weld/Morgan County line to the Colorado/Nebraska border.	all	Aquatic Life Use	Se, Mn	M	
COSPLS02b	Tributaries to S Platte River, Beaver Creek, Bijou Creek and Kiowa Creek	Beaver Creek		 Se, E. coli 	H	
COSPLS03	Jackson, Prewitt, North Sterling, Jumbo, Riverside, Empire and Vancil Reservoirs	North Sterling	D.O.			
COSPLS03	Jackson, Prewitt, North Sterling, Jumbo, Riverside, Empire and Vancil Reservoirs	North Sterling, Jackson and Jumbo Reservoirs	Se			
COSPLS03	Jackson, Prewitt, North Sterling, Jumbo, Riverside, Empire and Vancil Reservoirs	Jackson Reservoir		pH	H	
COSPMS01a	South Platte River from Big Dry Creek to St. Vrain Creek	all		E.coli	H	
COSPMS01b	South Platte River from St. Vrain Creek to Weld/Morgan County Line	all		Se	L	
COSPMS04	Barr Lake and Milton Reservoir	Milton Reservoir		D.O., pH, NH3, 	M/L	
COSPMS04	Barr Lake and Milton Reservoir	Barr Lake		pH, D.O.	M	
COSPMS07	All lakes and reservoirs trib to the South Platte River below Big Dry Creek to Weld/Morgan County Line	Horse Creek Reservoir		pH, NH3, D.O.	L	
COSPMS07	All lakes and reservoirs in watershed tributary to the South Platte from Chatfield to Big Dry Creek.	Prospect Lake		D.O., pH, NH3	M	
COSPRE04	Mainstem of Arikaree River from the confluence of the North and South Forks to the Kansas border.	all		 E.coli	H	
COSPRE05	Mainstem of the Black Wolf Creek from the source to the confluence with the Arikaree River.	all	E. coli, Se			
COSPSV02a	Mainstem of St. Vrain from Indian Peaks Wilderness Area and RMNP to eastern boundary of Roosevelt Ntl Forest	all		Zn	H	
COSPSV02b	St. Vrain Creek, RMNP to Hygiene Road	all		Cu, Temperature	H	
COSPSV03	St. Vrain Creek, Hygiene Rd. to S. Platte River	From the confluence with Left Hand Creek to the confluence with Boulder Creek		Aquatic Life Use (provisional)	L	
COSPSV03	St. Vrain Creek, Hygiene Rd. to S. Platte River	From Hover Road to the confluence with Left Hand Creek	Aquatic Life Use,			
COSPSV04a	Left Hand Creek, from source to blw confluence with James Creek	(Hwy 72 to James Ck); 		pH, Cu, Zn 	M	
COSPSV04b	James Creek, Little James Creek	Little James Creek 		Cu, Pb	M	
COSPSV04c	Left Hand Creek from James Creek to HWY 36	all		Cu, As	H	
COSPSV05	Mainstem of Left Hand Creek, including all tributaries and wetlands from Highway 36 to the confluence with St. Vrain Creek.	Upstream Lefthand Feeder Canal		Mn (WS)	L	
COSPSV05	Mainstem of Left Hand Creek, including all tributaries and wetlands from Highway 36 to the confluence with St. Vrain Creek.	Downstream Lefthand Feeder Canal		Cu	M	
COSPSV06	Tributaries to the St Vrain River	Dry Creek		E. coli	H	
COSPSV06	Tributaries to the St Vrain River	all		Se	L	
COSPSV13	All lakes and reservoirs tributary to Left Hand Creek from Hwy 36 to St. Vrain Creek.	Lake Thomas	D.O.			
COSPUS02a	Tributaries to S. Platte River, source to Tarryall Creek	Salt Creek d/s of N. Fork, on USFS Land	Temperature			
COSPUS02a	Tributaries to S. Platte River, source to Tarryall Creek	Twin Creek, on USFS Land	Temperature			
COSPUS02a	Tributaries to S. Platte River, headwaters to Tarryall Creek	S. Fork of S. Platte below Antero Reservoir	Aquatic Life			
COSPUS02b	Mosquito Creek from South Mosquito Creek to the Middle Fork of the South Platte.	all		Cd	H	
COSPUS02c	South Mosquito Creek from the source to the confluence with Mosquito Creek and No Name Creek from  the source to the confluence with Mosquito Creek	No Name Creek		Cd, Zn	H	
COSPUS03	Tributaries to S.Platte River, Tarryall Creek to N.Fk.S.Platte R	Trout Creek and tributaries on USFS property	Aquatic Life	sediment* 	H	
COSPUS03	Tributaries to S.Platte River, Tarryall Creek to N.Fk.S.Platte R	Pine Creek		As	H	
COSPUS03	Tributaries to S.Platte River, Tarryall Creek to N. Fk. S. Platte River	Pine Creek, on USFS Land	sediment			
COSPUS03	Tributaries to S.Platte River, Tarryall Creek to N.Fk.S.Platte R	Fourmile Creek		Fe(trec), As, Hg	H	
COSPUS03	Tributaries to S.Platte River, Tarryall Creek to N.Fk.S.Platte R	Sugar Creek, on USFS Land	sediment			
COSPUS03	Tributaries to S.Platte River, Tarryall Creek to N. Fk. S. Platte River	Hawkins Gulch	Cd, Se			
COSPUS03	Tributaries to S.Platte River, Tarryall Creek to N. Fk. S. Platte River	Horse Creek	D.O., Fe(trec)	Aquatic Life (provisional)	L	
COSPUS03	Tributaries to S.Platte River, Tarryall Creek to N. Fk. S. Platte River	West Creek	As, Hg			
COSPUS03	Tributaries to S.Platte River, Tarryall Creek to N. Fk. S. Platte River	Goose Creek	D.O.			
COSPUS03	Tributaries to S.Platte River, Tarryall Creek to N. Fk. S. Platte River	Trail and Wigwam Creeks	Fe(trec)			
COSPUS04	N. Fk. S. Platte River & Tributaries, source to S.Platte R	Hall Valley area to Geneva Ck		pH	H	
COSPUS05c	Gooseberry Gulch and all tributaries from source to confluence with Elk Creek.	Unnamed Tributary to Gooseberry Creek		NH3	M	
COSPUS06a	Mainstem of the South Platte River from the outlet of Cheesman Reservoir to the inlet of Chatfield Reservoir.	South Platte River from outlet of Cheesman Reservoir to Fourmile Creek	Aquatic Life			
COSPUS07	Tributaries to the South Platte from the North Fork of the South Platte to the outlet of Chatfield Reservoir.	Willow Creek	Fe(Trec), Se			
COSPUS09	Mainstem of Bear Creek, including all tributaries and wetlands from the source to the inlet of Perry Park Reservoir (Douglas County). 	

	Bear Creek	D.O.			
COSPUS10a	Mainstems of East Plum Creek, West Plum Creek, and Plum Creek from the boundary of national forest lands to Chatfield Reservoir, mainstems of Stark Creek and Gove Creek from the boundary of national forest lands to their confluence.	West Plum Creek		Aquatic Life (provisional)	L	
COSPUS11a	Tributaries to East Plum Creek which are not on national forest lands.	all	pH, Fe(Trec)			
COSPUS11a	Tributaries to East Plum Creek which are not on national forest lands.	Cook Creek		Aquatic Life (provisional)	L	
COSPUS11b	Tributaries to W. Plum Creek, not on USFS Land	Spring Creek, Bear Creek	Aquatic Life Use			
COSPUS12	Garber and Jackson Creeks	Jackson Creek	Pb			
COSPUS14	S. Platte River	all		As	H	
COSPUS15	S. Platte River, Burlington Ditch to Big Dry Creek	all		E. coli 	H	
COSPUS16a	Sand Creek	all		Se, E. coli	L/H	
COSPUS16c	Tributaries to S. Platte River, Chatfield Reservoir to Big Dry Creek except specific listings	all		Se	L	
COSPUS16c	Tributaries to S. Platte River, Chatfield Reservoir to Big Dry Creek except specific listings	Westerly Creek, Dry Creek		E. coli	H	
COSPUS16c	Tributaries to S. Platte River, Chatfield Reservoir to Big Dry Creek except specific listings	Weir Gulch, Sanderson Gulch, Humble Creek	E. coli			
COSPUS16c	Tributaries to S. Platte River, Chatfield Reservoir to Big Dry Creek except specific listings	Harvard, Harvard West, and Lakewood Gulches		E. coli (May-Oct)	H	
COSPUS17a	Washington Park Lakes, City Park Lake, Rocky Mountain Lake, Berkeley Lake	Berkeley Lake, Rocky Mountain Lake		Aquatic Life Use (Hg Fish Tissue)	H	
COSPUS17a	Washington Park Lakes, City Park Lake, Rocky Mountain Lake, Berkeley Lake	Rocky Mountain Lake	
Cu, D.O.	pH	L	
COSPUS17a	Washington Park Lakes, City Park Lake, Rocky Mountain Lake, Berkeley Lake	Ferril Lake, Smith Lake		pH	H	
COSPUS17a	Washington Park Lakes, City Park Lake, Rocky Mountain Lake, Berkeley Lake	Smith Lake		NH3	H	
COSPUS17a	Washington Park Lakes, City Park Lake, Rocky Mountain Lake, Berkeley Lake	Grasmere Lake	Cu			
COSPUS17a	Washington Park Lakes, City Park Lake, Rocky Mountain Lake, Berkeley Lake	Berkeley Lake		D.O., As	H	
COSPUS17a	Washington Park Lakes, City Park Lake, Rocky Mountain Lake, Berkeley Lake	Duck Lake		D.O., pH, NH3	H	
COSPUS17b	Sloan’s Lake	all	Fe (Trec)	D.O.		
COSPUS23	All lakes and reservoirs in watershed tributary to the South Platte from Chatfield to Big Dry Creek.	Barnum Lake		D.O.	L	
COSPUS23	Lakes and reservoirs in the Upper South Platte watershed within the City and County of Denver.	Vanderbilt Lake		D.O.		
COSPUS23	Lakes and reservoirs in the Upper South Platte watershed within the City and County of Denver.	Garfield Lake, Harvey Lake, Aqua Golf Lake	Fe(trec)			
COSPUS23	Lakes and reservoirs in the Upper South Platte watershed within the City and County of Denver.	Garfield Lake, , Parkfield Lake, Huston Lake		D.O.	M	
COSPUS23	Lakes and reservoirs in the Upper South Platte watershed within the City and County of Denver.	Aqua Golf Lake, Huston Lake, Overland Lake, Parkfield Lake		pH	M	
COSPUS23	Lakes and reservoirs in the Upper South Platte watershed within the City and County of Denver.	Huston Lake	E. coli			
COUC	Upper Colorado River Basin	 		 	 	
COUCBL02a	Mainstem of the Blue River from the confluence with French Gulch to a point one half mile below Summit County Road 3.	all		Mn(WS)	L	
COUCBL04a	All direct tributaries to Dillon Reservoir and all tributaries and wetlands in the Blue River drainage above Dillon Reservoir.	Gold Run Gulch below Jessie Mine	Cd, Zn			
COUCBL17	Mainstem of the Blue River from the outlet of Dillon Reservoir to the confluence with the Colorado River.	Blue River from outlet of Dillon Reservoir to N. Rock Creek confluence	Aquatic Life 			
COUCBL20	Mainstem of Elliott Creek and Spruce Creek including all tributaries and wetlands from their sources to the confluence with the Blue River	Spruce Creek	Fe(Trec)			
COUCEA05c	Eagle River, Martin Creek to Gore Creek	all		Cd	H	
COUCEA06	Tributaries to Eagle River, Belden to Lake Creek, except specific segments	Black Gore Creek, adjacent to I-70	Aquatic Life	Sediment	H	
COUCEA06	Tributaries to Eagle River, Belden to Lake Creek, except specific segments	Mainstem of Lake Creek from below the confluence with East and West Lake Creek to the mouth		Aquatic Life (provisional)	L	
COUCEA06	Tributaries to Eagle River, Belden to Lake Creek, except specific segments	Beaver Creek from confluence with Wayne Creek to Mouth	Aquatic Life 			
COUCEA06	Tributaries to Eagle River, Belden to Lake Creek, except specific segments	Red Sandstone Creek from USFS Boundary to north side I-70 Frontage Road	Aquatic Life 			
COUCEA06	Tributaries to Eagle River, Belden to Lake Creek, except specific segments	Red Sandstone Creek from north side I-70 Frontage Road to confluence with Gore Creek		Aquatic Life (provisional)	L	
COUCEA08	Mainstem of Gore Creek from the confluence with Black Gore Creek to the confluence with the Eagle River.	all		Aquatic Life (provisional)	L	
COUCEA09a	Mainstem of the Eagle River from Gore Creek to a point immediately below the confluence with Rube Creek.	From Berry Creek to confluence with Ute Creek	Temperature			
COUCEA09a	Mainstem of the Eagle River from Gore Creek to a point immediately below the confluence with Rube Creek.	From Ute Creek to confluence with Rube Creek		Temperature	H	
COUCEA09a	Mainstem of the Eagle River from Gore Creek to a point immediately below the confluence with Rube Creek.	Eagle River from confluence with Berry Creek to confluence with Squaw Creek	Aquatic Life 	Sediment	H	
COUCEA09a	Mainstem of the Eagle River from Gore Creek to a point immediately below the confluence with Rube Creek.	Eagle River from Gore Creek to confluence with Berry Creek and from Squaw Creek to confluence with Rube Creek	Sediment			
COUCEA10a	All tributaries to the Eagle River from Lake Creek to the Colorado River.	Eby Creek	Se			
COUCNP01	Tribs to the N Platte & Encampment Rivers w/in Wilderness Areas	South Fork Big Creek	Cu, E.coli			
COUCNP04a	Tributaries to the North Platte River except those tributaries in Segment 1, 4b, 6, 7a and 7b.	Canadian River	Fe(Dis), E. coli			
COUCNP04a	All tributaries to N. Platte River except segments 4b, 6, 7a and 7b	Grizzly Creek, Little Grizzly Creek	Aquatic Life Use			
COUCNP04a	All tributaries to N. Platte River except segments 4b, 6, 7a and 7b	Little Grizzly Creek	E.coli, Fe(Trec)			
COUCNP04a	All tributaries to N. Platte River except segments 4b, 6, 7a and 7b	Lake Creek	pH, Fe(Trec)			
COUCNP04a	All tributaries to N. Platte River except segments 4b, 6, 7a and 7b	Big Creek Reservoir	Aquatic Life Use (Hg Fish Tissue)			
COUCNP04b	Mainstem of the Illinois and Canadian Rivers, including all tributaries of the Illinois from Indian Creek to Michigan River  except for specific listings in Segments 7a and 7b, and all tribs of Canadian entering the mainstem from the Southwest.	Illinois River		Fe (Trec)	M	
COUCNP07b	Government Creek, Spring Creek	Spring Creek		D.O.	M	
COUCNP09	All lakes and reservoirs tributary to the North Platte and Encampment Rivers 
	Lake John, North Delaney Lake	pH			
COUCNP09	All lakes and reservoirs tributary to the North Platte and Encampment Rivers 
	Lake John		D.O.	H	
COUCRF03a	Roaring Fork including all tributaries and wetlands from Hunter Creek to the Colorado River except segments 3b through 10	Capitol Creek	Se			
COUCRF03a	Roaring Fork including all tributaries and wetlands from Hunter Creek to the Colorado River 	West Sopris Creek		Aquatic Life (provisional)	L	
COUCRF03a	Roaring Fork including all tributaries and wetlands from Hunter Creek to the Colorado River 	Cattle Creek from Bowers Gulch to mouth		Aquatic Life (provisional)	L	
COUCRF03a	Roaring Fork including all tributaries and wetlands from Hunter Creek to the Colorado River 	Roaring Fork from confluence with Hunter Creek to below Brush Creek confluence,		Aquatic Life (provisional)	L	
COUCRF03b	Red Canyon Creek including all tributaries and wetlands from the source to the Roaring Fork except Landis Creek from source to Hopkins Ditch Diversion	Landis Creek	Fe(Trec)			
COUCRF04	Mainstem of Brush Creek from the source to the confluence with the Roaring Fork River.	Mainstem Brush Creek		Aquatic Life (provisional)	L	
COUCRF07	All tributaries to the Fryingpan River	South Fork Frying Pan River from transbasin diversion to confluence with unnamed tributary (39.25128oN, -106.59442oW)		Aquatic Life (provisional)	L	
COUCRF10	Thompson Creek including all tributaries and wetlands from the source to the Crystal River	Thompson Creek	Fe(Trec)			
COUCUC02	Mainstem of the Colorado River, including all tributaries and wetlands within or flowing into Arapahoe National Recreation Area.	Willow Creek Reservoir		Mn	L	
COUCUC03	Mainstem of the Colorado River from Lake Granby to the Roaring Fork River.	From 578 Road Bridge to just above the confluence with the Blue River		Temperature, Mn(WS)	H	
COUCUC03	Mainstem of the Colorado River from Lake Granby to the Roaring Fork River.	From the outlet of Windy Gap Reservoir to 578 Road Bridge	Aquatic Life			
COUCUC06b	Mainstem of unnamed tributary from the headwaters to Willow Creek Reservoir Road	all	D.O.			
COUCUC07a	All tribs to the Colorado River, including wetlands from a point abv the confluence with the Blue River to blw confluence with the Roaring Fork, which are not on National Forest Lands except specific listings in segment 7b.	Alkali Slough		Fe (Trec), Se	L	
COUCUC07a	All tribs to the Colorado River, including wetlands from a point abv the confluence with the Blue River to blw confluence with the Roaring Fork, which are not on National Forest Lands except specific listings in segment 7b.	Muddy Creek and tribs	Temperature			
COUCUC07b	Muddy Creek from Wolford Mountain Reservoir.  Rock Creek, Deep Creek, Sheephorn Creek Sweetwater Creek and Piney River.  	Muddy Creek from Wolford Mountain Reservoir to Cow Gulch	Temperature			
COUCUC07b	Muddy Creek from Wolford Mountain Reservoir.  Rock Creek, Deep Creek, Sheephorn Creek Sweetwater Creek and Piney River.  	Muddy Creek from Cow Gulch to the Colorado River		Temperature	H	
COUCUC10a	Mainstem of the Fraser River from the source to a point immediately below the Rendezvous Bridge. All tributaries to the Fraser River, from the source to the Colorado River	Fraser River, Vasquez Creek		Aquatic Life (provisional)	L	
COUCUC10a	Mainstem of the Fraser River from the source to a point immediately below the Rendezvous Bridge. All tributaries to the Fraser River, from the source to the Colorado River.	Ranch Creek		Temperature	L	
COUCUC10c	Mainstem of the Fraser River from Hammond Ditch to the Colorado River.	all		Temperature	L	
COUCUC10c	Mainstem of the Fraser River, from the Hammond Ditch to the confluence with the Colorado River	From the Town of Fraser to the confluence with the Colorado River.	Cu			
COUCUC10c	Mainstem of the Fraser River, from the Hammond Ditch to the confluence with the Colorado River	From the Town of Tabernash to the Town of Granby	Pb			
COUCUC12	Colorado River and tributaries, wetlands, lakes and reservoirs within Arapahoe National Recreation Area	Shadow Mountain Lake	
	D.O.	H	
COUCUC12	Lakes and Reservoirs within Arapahoe National Recreation Area including Grand Lake, Shadow Mountain Lake and Lake Granby	Lake Granby		Aquatic Life Use (Hg Fish Tissue)	H	
COUCYA02a	Mainstem of the Yampa River from Wheeler Creek to Oak Creek.	Yampa River below Stagecoach Reservoir	Mn, Se			
COUCYA02b	All lakes and reservoirs tributary to the Yampa River, Elkhead Creek, and the Little Snake River.	Elkhead Reservoir, Catamount		Aquatic Life Use (Hg Fish Tissue)	H	
COUCYA02c	Yampa River from Oak Creek to Elkhead Creek	all	Temperature			
COUCYA03	All tributaries to Yampa River except for specific listings, on USFS land	Bushy Creek		Sediment	L	
COUCYA03	All tributaries to Yampa River except for specific listings, on USFS land	Walton Creek	Mn			
COUCYA03	All tributaries to Yampa River except for specific listings, on USFS land	Little Morrison Creek	Zn, Fe(dis)			
COUCYA04	Little White Snake Creek, source to Yampa River	all	D.O.			
COUCYA08	Elk River source to Yampa River	Elk River below Morin Ditch		E.coli	H	
COUCYA08	Elk River including tributaries and wetlands from the source to Yampa River	Lost Dog Creek	Hg			
COUCYA13b	Foidel Creek and tributaries, Fish Creek, Middle Creek and tributaries	Fish Creek	E.coli			
COUCYA13d	Dry Creek including all wetlands and tributaries from source to the Yampa River	Below Seneca sample location 8 (WSD5)		Se	L	
COUCYA13d	Dry Creek including all tributaries and wetlands from source to the Yampa River	all		Fe(Trec) (Snowmelt season)	L	
COUCYA13d	Dry Creek including all tributaries and wetlands from the source to the Yampa River	Dry Creek below Routt County Road 53 (Sec. 22, T6N, R88W)	Pb, E. Coli			
COUCYA13e	Sage Creek, Grassy Creek and tribs	Sage Creek below Routt County Road 51D		Se	L	
COUCYA15	Mainstem of Elkhead Creek and tributaries Calf Creek and 80A Road on the Dry Fork of Elkhead Creek, to the confluence with the Yampa River.	Elkhead Creek		Aquatic Life (provisional)	L	
COUCYA18	Little Snake River including all tributaries and wetlands from forest boundary to Wyoming border	all	Cu			

. . . . 
93.13	STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE; DECEMBER 2011 RULEMAKING, EFFECTIVE DATE OF MARCH 30, 2012
The provisions of C.R.S. 25-8-202(1)(a), (b) and (i), (2) and (6); 25-8-203; 25-8-204; and 25-8-401; provide the specific statutory authority for adoption of these regulatory amendments.  The Commission also adopted in compliance with 24-4-103(4) C.R.S. the following statement of basis and purpose.
BASIS AND PURPOSE
A.	Revisions to 303(d) List
1.	Introduction
This regulation updates Colorado’s List of Water-Quality-Limited Segments Requiring Total Maximum Daily Loads (TMDLs) to reflect additional water quality information available since the Regulation was revised in 2010.  This list was prepared to fulfill section 303(d) of the federal Clean Water Act (Act) which requires that states submit to the U.S. Environmental Protection Agency (EPA) a list of those waters for which technology-based effluent limitations and other required controls are not stringent enough to implement water quality standards.
This regulation also updates Colorado’s Monitoring and Evaluation List (M&E List) to reflect additional water quality information available since the Regulation was revised in 2010.
2.	List Development
a.	Listing Methodology
The “Section 303(d) Listing Methodology - 2012 Listing Cycle” contains a description of the listing process, the criteria for listing, and the criteria for determination of TMDL priority.  The Listing Methodology was developed through a public process and finalized as a policy at a Water Quality Control Commission administrative action hearing in March 2011.
This Listing Methodology sets forth the criteria that generally were used to make decisions regarding which waters to include on the 2012 Section 303(d) List and the  2012 M&E List.  However, this methodology was not adopted by the Commission as a rule.  The Commission therefore has the flexibility to take into account other appropriate factors in making site-specific listing decisions.
b.	Information Considered
The Commission has considered all existing and readily available information in developing the 2012 Section 303(d) List.  In determining whether data and information are existing and readily available, it has taken into account such data and information as the Division has utilized in the preparation of those identification processes, calculations and models referenced in 40 CFR §130.7(a)(5)(i), (ii) and (iv) and that credible data and information presented in a readily usable format and submitted in reports provided to the Division as referenced in 40 CFR §130.7(a)(5)(iii).  In addition, the Commission accepted credible data and information that was submitted in accordance with the listing process schedule, whether submitted by EPA or any other interested party.  The Division also continues to independently collect and analyze new data on a rotating basin basis as part of its triennial review efforts and will utilize such data and information in making future listing determinations.  Existing data which was not brought forward through one of the above mechanisms or otherwise presented to the Commission in accordance with the schedule was not treated as "readily available" for purposes of making the 2012 listing decisions.  Such information will be considered in the next listing cycle.
c.	Data Quality
In the Water Quality Control Division's (WQCD) Quality Management Plan 2011 for the Collection and Utilization of Environmental Data, the WQCD states that "It is the expressed goal of the Division to use only those analytical data that are both reliable and have a defined level of quality."  
3.	Prioritization
The objective of prioritization is to identify those waterbody segments where the Division and the public should concentrate their resources.  Priorities of High, Medium and Low were established according to section IV. of the 2012 Section 303(d) Listing Methodology.  
The Division remains committed to establishing a plan for monitoring and evaluating water bodies on the M&E List prior to the list submission date for the subsequent listing cycle. Further, the Commission has committed to determining their appropriate status (as either impaired or fully supporting) within ten years of their placement on the M&E List.
4.	Fish Mercury (Hg) Listings
The 303(d) Listing Methodology was revised in 2012 for the assessment of Fish Mercury (Hg).  The newly adopted methods compare the median fish Hg for each waterbody and species to a 0.3 ppm threshold.    A sample size requirement of 30 fish tissue samples per waterbody/species was also introduced in order to list new waterbodies for Fish Hg.  Waterbodies can also be listed if there is overwhelming evidence of impairment (>0.45 ppm Hg) and a sample size of at least 10 fish tissue samples. 
The Commission retained the following 6 lakes on the 303(d) List because these lakes have a median Hg above the 0.3 ppm threshold and either meet the sample size requirements or show overwhelming evidence of impairment:
●	Upper South Platte Segment 23, Berkeley Lake (COSPUS23)
●	Upper Arkansas Segment 27, Brush Hollow Reservoir (COARUA27)
●	Cache la Poudre Segment 14, Horsetooth Reservoir (COSPCP14)
●	Upper South Platte Segment 17a, Rocky Mountain Lake (COSPUS17a)
●	Lower Arkansas Segment 5b, Trinidad Reservoir (COARLA05b)
●	Los Pinos Segment 3, Vallecito Reservoir (COSJPN03)
The Commission retained the following 10 lakes on the 303(d) List because they were on the 303(d) List prior and have a median Hg of greater than 0.3 ppm. Although the 2012 Listing Methodology requires a minimum sample size of thirty fish, the Commission chose to retain these segments on the 303(d) List as opposed to the Monitoring and Evaluation List:  
●	Big Thompson Segment 11, Carter Reservoir (COSPBT11)
●	Yampa River Segment 2b, Catamount Reservoir (COUCYA02b)
●	San Juan Segment 6a, Echo Canyon Reservoir (COSJSJ06a)
●	Yampa River Segment 2b, Elkhead Reservoir (COUCYA02b)
●	Middle Arkansas Segment 16, Horseshoe Lake– Lathrop (COARMA16)
●	Dolores River Segment 4, McPhee Reservoir (COSJDO04)
●	Los Pinos, Segment 11, Narraguinnep Reservoir (COSJLP11)
●	Lower Colorado Segment 20, Rifle Gap Reservoir (COLCLC20)
●	La Plata Segment 11, Totten Reservoir (COSJLP11)
●	Upper Arkansas Segment 14b, Teller Reservoir (COARUA14b)
The Commission retained the following 2 lakes on the 303(d) List because they were on the 303(d) List prior to the adoption of the new assessment methods.  With median Fish Hg concentrations below 0.3 ppm, they will not be removed from the 303(d) List, however, until a minimum of 30 fish are collected:
●	Big Thompson Segment 12, Boyd Lake (COSPBT12)
●	Upper Colorado Segment 12, Lake Granby (COUCUC12)
The Commission added the following 3 lakes on the Monitoring and Evaluation List because they have a median Fish Hg of greater than 0.3 ppm but the sample size is insufficient for Listing:
●	North Platte Segment 4a, Big Creek Lake (COUCNP04a)
●	Boulder Segment 15, Gross Reservoir (COSPBO15)
●	Big Thompson Segment 14, Lonetree Reservoir (COSPBT14)
The Commission removed the following lake from the 303(d) List.  Additional data was collected meeting the minimum sample size requirement of thirty fish.  Median Fish Hg concentrations are below the 0.3 ppm, threshold. 
●	Lower Gunnison Segment 4, Juniata Reservoir (COGULG04)
The Commission retained one listing based on non-attainment of the aquatic life use due to a PCE fish consumption advisory in Willow Springs Ponds, Fountain Creek, Segment 7a.
5.	Aquatic Life Listings
280 Multimetric Index (MMI) scores were calculated for the 2012 listing cycle, utilizing the Water Quality Control Commission’s (WQCC) Policy 10-1, Aquatic Life Use Attainment.  Of the 280 MMI scores generated, 48 segments were found to be not attaining the Aquatic Life Use standard.  From those segments, or portions of segments, determined to be in non-attainment, 31 will be provisionally listed, as there is currently no water quality data available to indicate impairment.  This is in accordance with the Section 303(d) Listing Methodology for the 2012 Listing Cycle, approved by the WQCC in March 2011.  The Commission anticipates that the Division will collect additional data for these segments in the next two years to continue the investigation into potential sources. Because of the site-specific nature of macroinvertebrate data, waterbodies in all tributary segments that were identified as impaired for their Aquatic Life Use were listed individually.  
The following segment was 303(d) listed for non-attainment of the Aquatic Life Use based on Policy 10-1: 
●	White River, Segment 13c, Yellow Creek (COLCWH13c)
The following segments were provisionally 303(d) listed for non-attainment of their Aquatic Life Use based on Policy 10-1: 
●	Upper Arkansas Segment 21a, Cripple Creek (COARUA21a)
●	San Miguel Segment 12, Maverick Draw (COGUSM12)
●	Upper Gunnison Segment 6b, Cement Creek (COGUUG06b)
●	Upper Gunnison Segment 15, S. Beaver Creek (COGUUG15)
●	Upper Gunnison Segment 24, Cochetopa Creek from Forest Road 3076/Co. Rd 43 to 
	confluence with Tomichi Creek (COGUUG24)
●	Upper Gunnison Segment 29a, Lake Fork Gunnison River between Cooper and Silver 
	Creek (COGUUG29a)
●	Uncompahgre Segment 11, Deer Creek (COGUUN11)
●	Lower Yampa Segment 22a, Talamantes Creek COLCLY22a)
●	White River Segment 15, Piceance Creek (COLCWH15)
●	White River Segment 20, Black Sulphur Creek (COLCWH20)
●	White River Segment 23, West Douglas Creek (COLCWH23)
●	Rio Grande Segment 12, Rio Grande River (CORGRG12)
●	Bear Creek Segment 1a, Bear Creek from Witter Gulch to inlet to Evergreen Lake 
	(COSPBE01a)
●	Boulder Creek Segment 9, Boulder Creek from 107th Street to confluence with Coal 
	Creek (COSPBO09)
●	Clear Creek Segment 14a, Clear Creek from Croke Canal diversion to McIntyre Street 
	(COSPCL14a)
●	St. Vrain Segment 3, St. Vrain Creek (COSPSV03), from Left Hand Creek 
	confluence to confluence with Boulder Creek 
●	Upper South Platte Segment 3, Horse Creek (COSPUS03)
●	Upper South Platte Segment 10a, West Plum Creek (COSPUS10a)
●	Upper South Platte Segment 11a, Cook Creek (COSPUS11a)
●	Eagle River Segment 6, Lake Creek (from below the confluence with East and West Lake 
	Creek to the mouth), and Red Sandstone Creek (from north side I-70 Frontage Road to the 
	confluence with Gore Creek) (COUCEA06)
●	Eagle River Segment 8, Gore Creek (COUCEA08)
●	Roaring Fork Segment 3a, Roaring Fork from Hunter Creek to Brush Creek confluence, 
	Cattle Creek from Bowers Gulch to Mouth, W. Sopris Creek (COUCRF03a)
●	Roaring Fork Segment 4, Brush Creek (COUCRF04)
●	Roaring Fork Segment 7, South Fork Frying Pan River from transbasin diversion to 
	confluence with unnamed tributary (COUCRF07)
●	Upper Colorado Segment 10a, Fraser River, Vasquez Creek (COUCUC10a)
●	Yampa River Segment 15, Elkhead Creek (COUCYA15)
The following segments were included on the M&E List for possible non-attainment of their Aquatic Life Use based on Policy 10-1: 
●	Bear Creek Segment 1e, Bear Creek (COSPBE01e)
●	White River Segment 13b, Duck Creek (COLCWH13b)
●	Eagle River Segment 6, Black Gore Creek Beaver Creek (from Wayne Creek to Mouth), 
	Red Sandstone Creek (from USFS boundary to north side I-70 Frontage Road) 
	(COUCEA06)
●	Eagle River Segment 9a, Eagle River (from confluence with Berry Creek to confluence with 
	Squaw Creek) (COUCEA09a)
Several segments were found to have data outside of the standard index period for data collection.  The Commission included these segments on the Monitoring and Evaluation (M&E) List in order to gather more information within the standard index period.  The following segments were listed on the M&E List for possible non-attainment of their Aquatic Life Use based on Policy 10-1: 
●	Fountain Creek Segment 4, Sand Creek (COARFO04)
●	Upper Arkansas Segment 5, Lake Fork Creek (COARUA05)
●	Upper Gunnison Segment 8, Slate River (COGUUG08)
●	Saint Vrain Segment 3, Saint Vrain Creek from Hover Road to the confluence with Left 
	Hand Creek (COSPSV03)
●	Boulder Creek Segment 7b, Coal Creek (COSPBO07b)
●	Bear Creek Segment 2, Bear Creek (COSPBE02)
●	Clear Creek Segment 1,  Kearney Gulch, Grizzly Gulch (COSPCL01)
Various parties questioned whether or not the data collected below reservoirs should be evaluated as being representative of an entire stream segment. They recommend that listings below reservoirs be placed on the M&E List while the applicability of the current thresholds below reservoirs is investigated. The Division agreed that a study was warranted and changed its proposal to the M&E List.  The Commission placed the following segments on the M&E List for possible non-attainment of their Aquatic Life Use:
●	COUCBL17, Blue River from outlet of Dillon Reservoir to N. Rock Creek confluence 
●	COARUA05, Lake Fork below Sugarloaf Dam 
●	COSPUS02a, South Fork South Platte River below Antero 
●	COSPUS06a, South Platte River below Cheesman at Cheesman Canyon 
●	COSPUS03, Trout Creek below Manitou Reservoir Dam 
●	COUCUC03, Colorado River from below Windy Gap Reservoir to FR 538
Several segments were found to have data outside of the assessed period of record.  Therefore, the Division proposed to remove them from both the 303(d) and M&E Lists.  The Commission did not include these segments on either list:
●	Upper Arkansas Segment 5, S. Cottonwood Creek (COARUA05)
●	Upper Arkansas Segment 18, Currant Creek (COARUA18)
●	San Miguel Segment 2, Howard Fork (COGUSM02)
●	Rio Grande Segment 2, South Clear Creek (CORGRG02)
●	Animas and Florida Segment 13c, Salt Creek (COSJAF13c)
●	Big Thompson Segment 2, Big Thompson River (COSPBT02)
●	Blue River Segment 17, Blue River from N. Rock Creek confluence to Colorado River 
	(COUCBL17)
●	North Platte Segment 4a, Snyder Creek (COUCNP04a)
●	Upper Colorado Segment 7a, Big Alkali Creek (COUCUC07a)
Other issues were raised in this rulemaking hearing in regards to listing decisions based on the assessment of macroinvertebrate data.  In October 2010, the Commission adopted the Aquatic Life Use Attainment WQCC Policy 2010-1 which determined that the Colorado MMI is an appropriate tool for the quantitative bioassessment of the health of aquatic communities. The Commission adopted the 2012 Listing Methodology in March 2011. This Regulation No. 93 rulemaking hearing is the first occasion where the policies adopted by the Commission in Policy 2010-1 are being implemented into regulation. The Division followed the policies as defined in the methodologies to the intent for which they were adopted. The Commission recognizes that some of the policy decisions that were questioned by various parties may need additional review.  The Commission directs the Division and interested parties to review WQCC Policy 2010-1 and the 2012 Listing Methodology and make appropriate changes in regards to the use of data for the MMI tool. 
6.	Listings Due to Exceedances of the Secondary Water Supply Standards
For the secondary water supply standards of dissolved iron, manganese and sulfate, the less restrictive of the following two options will apply as the numeric standard: existing quality as of January 1, 2000 or the table value criteria in Regulation No. 31, Tables II and III. For dissolved iron this value is 300 ug/l. For manganese this value is 50 ug/l. For sulfate this value is 250 mg/l.
The Division evaluated the water quality as of January 1, 2000 to determine in some cases where standards exceeded the water supply criteria in Tables II and III. The following segments were included on the 303(d) listing based on exceedances of the standards:
●	Lower Gunnison Segment 4a, Whitewater Creek from below Brandon Ditch to confluence 
	with Gunnison River: Manganese, Sulfate (COGULG04a)
●	North Fork Segment 6b, Alum Gulch: Sulfate (COGUNF06b)
●	Upper Gunnison Segment 11, Coal Creek: Manganese (COGUUG11)
●	Upper Gunnison Segment 29a, Lake Fork Gunnison River: Manganese (COGUUG29a)
●	Upper Gunnison Segment 32, N. Fork Henson Creek: Manganese (COGUUG32)
●	Uncompahgre Segment 2, Uncompahgre River: Manganese (COGUUN02)
●	Animas and Florida Segment 5a, Animas River: Manganese (COSJAF05a)
●	La Plata Segment 4a, E. Mancos River, Manganese (COSJLP04a)
●	Big Thompson Segment 8, Little Thompson River: Sulfate (COSPBT08)
●	Clear Creek Segment 15, Clear Creek: Manganese (COSPCL15)
●	Saint Vrain Segment 5, Left Hand Creek: Manganese (COSPSV05)
●	Blue River Segment 2a, Blue River: Manganese (COUCBL02a)
●	Upper Colorado Segment 3, Colorado River: Manganese (COUCUC03)
The following segments were included on the M&E List:
●	Lower Gunnison Segment 4a, Callow Creek, Cummings Gulch, Peach Valley Creek: 
	Sulfate (COGULG04a)
●	Lower Gunnison Segment 4b, Kannah Creek: Sulfate (COGULG04b)
●	North Fork Segment 6b, Cottonwood Creek: Manganese, Sulfate (COGUNF06b)
●	San Miguel Segment 8, S. Fork San Miguel River: Manganese (COGUSM08)
●	Upper Gunnison Segment 15, S. Beaver Creek: Manganese, Dissolved Iron 
	(COGUUG15)
●	Upper Gunnison Segment 17, Antelope Creek: Manganese (COGUUG17)
●	Upper Gunnison Segment 23, Cochetopa Creek: Dissolved Iron (COGUUG23)
●	Uncompahgre Segment 11, Cow Creek: Sulfate (COGUUN11)
●	Piedra River Segment 6a, Stollsteimer Creek: Sulfate (COSJPI06a)
7.	Delisting of Segments with Recently Approved TMDLs
The Division submitted 26 TMDLs to EPA in the last biennium that have been approved. The following segments and parameters have been removed from the 303(d) List:
●	Arkansas, Upper Arkansas Segment 10, Lake Creek: Cu (COARUA10)
●	Gunnison, Lower Gunnison Segment 2, Gunnison River: Se (COGULG02)
●	Gunnison, Lower Gunnison Segment 4a, Tributaries to Gunnison River: Se 
	(COGULG04a)
●	Gunnison, Lower Gunnison Segment 4c, Red Rock Creek: Se (COGULG04c)
●	Gunnison, North Fork Segment 3, North Fork Gunnison River: Se (COGUNF03)
●	Gunnison, North Fork Segment 5, Leroux Creek, Jay Creek: Se (COGUNF05)
●	Gunnison, North Fork Segment 6a, Short Draw: Se (COGUNF06a)
●	Gunnison, North Fork Segment 6b, Big Gulch, Cottonwood Creek: Se (COGUNF06b)
●	Gunnison, San Miguel Segment 3a, San Miguel River: Cd (COGUSM03a)
●	Gunnison, San Miguel Segment 6a, Ingram Creek: Cd (COGUSM06a)
●	Gunnison, San Miguel Segment 6b, Marshall Creek: Cd (COGUSM06b)
●	Gunnison, Upper Gunnison Segment 30, Henson Creek: Cd, Zn(sc) (COGUUG30)
●	Gunnison, Upper Gunnison Segment 31, Palmetto Gulch: Cd, Zn (COGUUG31)
●	Gunnison, Uncompahgre Segment 4b, Uncompahgre River: Se (COGUUN04b)
●	Gunnison, Uncompahgre Segment 4c, Uncompahgre River: Se (COGUUN04c)
●	Gunnison, Uncompahgre Segment 12, Tributaries to Uncompahgre River: Se 
	(COGUUN12)
●	South Platte, Boulder Segment 2b, Boulder Creek from 13th Street to the confluence with 
	South Boulder Creek: E. coli (COSPBO02b)
●	South Platte, Boulder Segment 4a, Gamble Gulch: Cd (COSPBO04a)
●	South Platte, Upper South Platte Segment 5a, Geneva Creek: Cd, Cu, Zn (COSPUS05a)
●	South Platte, Upper South Platte Segment 5b, Geneva Creek: Cd (COSPUS05b)
●	South Platte, Upper South Platte Segment 15, South Platte River: Cd (COSPUS15)
●	Upper Colorado, Blue River Segment 12, Illinois Gulch: Cd (COUCBL12)
8.	Delisting of Segments where Water Quality is Currently Meeting Standards
As additional water quality data is collected and assessed, new data may show attainment of the standards. The following segments and parameters have been removed from the 303(d) List due to attainment of current water quality standards:
●	Arkansas, Fountain Creek Segment 1a, Fountain Creek: Se (COARFO01a)
●	Arkansas, Fountain Creek Segment 2b, Fountain Creek: Se (COARFO02b)
●	Arkansas, Fountain Creek Segment 6, Monument Creek below Mesa Road: Se 
	(COARFO06)
●	Arkansas, Lower Arkansas Segment 4, Lorencito Canyon: Se (COARLA04)
●	Arkansas, Lower Arkansas Segment 5a, Purgatoire River: Se (COARLA05a)
●	Gunnison, Lower Dolores Segment 1, Dolores River: Fe(Trec) (COGULD01)
●	Gunnison, Lower Gunnison Segment 2, Gunnison River: SO4 (COGULG02)
●	Gunnison, Lower Gunnison Segment 8, Kannah Creek: Se (COGULG08)
●	Gunnison, Upper Gunnison Segment 11, Coal Creek: Pb (COGUUG11)
●	Lower Colorado, Lower Colorado Segment 3, Colorado River mainstem: Se (COLCLC03)
●	South Platte, Middle South Platte Segment 4, Barr Lake: NH3 (COSPMS04)
●	South Platte, Upper South Platte Segment 23, Barnum Lake: E. coli (COSPUS23)
The following segments and parameters have been removed from the M&E List due to attainment of current water quality standards:
●	Arkansas, Upper Arkansas Segment 20, North Fork Wilson Creek: Cu (COARUA20)
●	Arkansas, Upper Arkansas Segment 27, Brush Hollow Reservoir: pH (COARUA27)
●	Gunnison, Lower Gunnison Segment 7, Surface Creek: Fe(Trec) (COGULG07)
●	Gunnison, Lower Gunnison Segment 7, Ward Creek: Se (COGULG07)
●	Gunnison, San Miguel Segment 2, Bilk Creek: Cd (COGUSM02)
●	Gunnison, Upper Gunnison Segment 7, Slate River: Cd (COGUUG07)
●	Gunnison, Upper Gunnison Segment 16, Ohio Creek: Zn(sculpin) (COGUUG16)
●	Upper Gunnison Segment 17, Antelope Creek: Dissolved Oxygen (COGUUG17)
●	Gunnison, Upper Gunnison Segment 18, Tomichi Creek: E. coli (COGUUG18)
●	Gunnison, Upper Gunnison Segment 32, N. Fork Henson Creek: Pb, Zn(sculpin) 
	(COGUUG32)
●	Gunnison, Uncompahgre Segment 8, Mineral Creek: Cd (COGUUN08)
●	Lower Colorado, Lower Colorado Segment 2b, Colorado River mainstem: Se 
	(COLCLC02b)
●	Rio Grande, Alamosa Segment 11, La Jara Reservoir: Cu, Se, Zn (CORGAL11)
●	South Platte, Big Thompson Segment 11, Carter Lake: Cu (COSPBT11)
●	South Platte, Big Thompson Segment 16, Lake Estes: As (COSPBT16)
●	South Platte, Cache la Poudre Segment 14, Horsetooth Reservoir: D.O. (COSPCP14)
●	South Platte, Lower South Platte Segment 3, N. Sterling and Jumbo Reservoirs: pH 
	(COSPLS03)
9.	Dissolved Oxygen Standard in Lakes and Reservoirs
Twenty-eight lakes were previously on the M&E List due to low dissolved oxygen (DO) in the metalimnion.  With the adoption of a revised DO standard in 2011, the Division proposed to remove 24 of these lakes from the M&E list because the lakes are now in attainment.  Barr Lake was proposed for the 303(d) List for DO because recent data show non-attainment.  The Division proposed that Horse Creek Reservoir, North Sterling Reservoir and Lake Thomas remain on the M&E list for DO either because of a minimal sample size (n=1) or due to concerns of the representative nature of the data.  The Commission supported the Division’s proposal.
Lakes now in attainment with the revised DO standard:
●	Upper South Platte Segment 16b, Aurora Reservoir (COSPUS16b)
●	Boulder Segment 14, Barker Reservoir (COSPBO14)
●	Bear Creek Segment 1c, Bear Creek (COSPBE01C)
●	Rio Grande Segment 9, Beaver Creek Reservoir (CORGRG09)
●	St. Vrain Segment 7, Boulder Reservoir (COSPSV07)
●	Big Thompson Segment 12, Boyd Lake (COSPBT12)
●	Upper South Platte Segment 19, Cheesman Reservoir (COSPUS19)
●	Cherry Creek Segment 2, Cherry Creek Reservoir (COSPCH02)
●	Upper South Platte Segment 19, Elevenmile Reservoir (COSPUS19)
●	Big Thompson Segment 12, Horseshoe (Loveland) Lake (COSPBT12)
●	Cache la Poudre Segment 14, Horsetooth Reservoir (COSPCP14)
●	Big Thompson Segment 14, Lon Hagler Reservoir (COSPBT14)
●	Big Thompson Segment 14, Lonetree Reservoir (COSPBT14)
●	Big Thompson Segment 12, Lake Loveland (COSPBT12)
●	Upper South Platte Segment 22, Marston Reservoir (COSPUS22) - Now identified as Bear 
	Creek Segment 11 (COSPBE11)
●	Upper South Platte Segment 16c, Quincy Reservoir (COSPUS16c)
●	Upper South Platte Segment 19, Spinney Mountain Reservoir (COSPUS19)
●	Yampa River Segment 2b, Stagecoach Reservoir (COUCYA02b)
●	Big Dry Segment 2, Standley Lake (COSPBD02)
●	Uncompahgre River Segment 14, Sweitzer Reservoir (COGUUN14)
●	Upper South Platte Segment 2a, Tarryall Reservoir (COSPUS02a)
●	St. Vrain Segment 9, Union Reservoir (COSPSV09)
●	Upper South Platte Segment 23, Vanderbilt Lake, Harvey Lake, Duck Lake (COSPUS23)
●	Upper Colorado Segment 5, Wolford Mountain Reservoir (COUCUC05)
The Commission moved the following lakes to the 303(d) List for D.O.:
●	Middle South Platte Segment 4, Barr Lake (COSPMS04)
●	Middle South Platte Segment 7, Horse Creek Reservoir (COSPMS07)
●	Upper South Platte Segment 23, Vanderbilt Lake (COSPUS23)
The Commission retained the following lakes on the M&E List for D.O.:
●	Lower South Platte Segment 3, North Sterling Reservoir (COSPLS03)
●	St. Vrain Segment 7, Thomas Reservoir (COSPSV07)
10.	Listing of Segments where Water Quality is not Meeting Standards not Identified Above
The following segments or parameters were added to the 303(d) List due to exceedances of water quality standards not identified above:
●	Arkansas, Upper Arkansas Segment 20, North Fork Wilson Creek: As (COARUA20)
●	Gunnison River, Lower Gunnison Segment 3, Eggleston Reservoir: Fe(Trec) (COGULG03)
●	Gunnison River, Lower Gunnison Segment 7, Tongue Creek: Fe(Trec) (COGULG07)
●	Gunnison River, Lower Gunnison Segment 13, Crawford Reservoir: D.O. (temperature) 
	(COGULG13)
●	Gunnison River, North Fork Gunnison Segment 4, East Muddy Creek: Fe(Trec) 
	(COGUNF04)
●	Gunnison River, North Fork Gunnison Segment 6b, Alum Gulch: SO4, Fe(Trec) 
	(COGUNF06b)
●	Gunnison River, San Miguel Segment 2, Bear Creek: Cd, Zn(sc) (COGUSM02)
●	Gunnison River, San Miguel Segment 2, Howard Fork abv Swamp Gulch: pH, D.O. 
	(COGUSM02)
●	Gunnison River, San Miguel Segment 11, Miramonte Reservoir: D.O. (temperature) 
	(COGUSM11)
●	Gunnison River, Upper Gunnison Segment 9, Coal Creek: As (COGUUG09)
●	Gunnison River, Upper Gunnison Segment 11, Elk Creek: As (COGUUG11)
●	Gunnison River, Upper Gunnison Segment 11, Coal Creek: Cd, Zn, As (COGUUG11)
●	Gunnison River, Upper Gunnison Segment 12, Coal Creek: Cu (COGUUG12)
●	Gunnison River, Upper Gunnison Segment 26, Blue Creek: Cu (COGUUG26)
●	Gunnison River, Uncompahgre Segment 4c, Uncompahgre River: Fe(Trec) 
	(COGUUN04c)
●	Gunnison River, Uncompahgre Segment 6a, Red Mountain Creek: Ag, Cu 
	(COGUUN06a)
●	Gunnison River, Uncompahgre Segment 7, Gray Copper Gulch: Cu (COGUUN007)
●	Gunnison River, Uncompahgre Segment 9, Sneffels Creek: Cd, (COGUUN09)
●	Gunnison River, Uncompahgre Segment 12, Dry Creek: Fe(Trec) (COGUUN12)
●	Gunnison River, Uncompahgre Segment 12, Loutzenhizer Arroyo: Fe(Trec) 
	(COGUUN12)
●	Gunnison River, Lower Dolores Segment 5, Roc Creek: Cu, Fe(Trec) (COGULD05)
●	Lower Colorado, Lower Colorado Segment 13b, Leach Creek:  E. coli, Fe(Trec) 
	(COLCLC013b)
●	Lower Colorado, White River Segment 13c, Yellow Creek: Fe(Trec) (COLCWH13c)
●	Lower Colorado, White River Segment 14a, Piceance Creek from Willow Creek to Hunter 
	Creek: Fe(Trec) (COLCWH14a)
●	San Juan/Dolores Rivers, Animas and Florida Segment 3c, Arrastra Gulch: Cd, Zn 
	COSJAF03c)
●	San Juan/Dolores Rivers, Animas and Florida Segment 4a, Animas River: Al(Trec) 
	(COSJAF04a)
●	San Juan/Dolores Rivers, La Plata Segment 1, La Plata River: Ag (COSJLP01)
●	San Juan/Dolores Rivers, La Plata Segment 4a, E. Mancos River: D.O. (COSJLP04a)
●	San Juan/Dolores Rivers, La Plata Segment 4a, Mancos River: D.O. (COSJLP04a)
●	San Juan/Dolores Rivers, La Plata Segment 7a, McElmo Creek: Fe(Trec), E. coli 
	(COSJLP07a)
●	San Juan/Dolores Rivers, La Plata Segment 8a, Mud Creek: Se (COSJLP08a)
●	San Juan/Dolores Rivers, La Plata Segment 8a, Trail Canyon: Fe(Trec) (COSJLP08a)
●	San Juan/Dolores Rivers, San Juan Segment 6a, Echo Canyon Reservoir:  DO 
	(Temperature) 
	(COSJSJ06a)
●	South Platte, Bear Creek Segment 1a, Bear Creek: Temperature (COSPBE01a)
●	South Platte, Bear Creek Segment 1e, Bear Creek: Temperature (COSPBE01e)
●	South Platte, Cherry Creek Segment 3, Cherry Creek: Fe(Trec) (COSPCH03)
●	South Platte, Clear Creek Segment 17b, Ralston Creek: U (COSPCL17b)
●	South Platte, Upper South Platte Segment 17a, Smith Lake: NH3 (COSPUS17a)
●	South Platte, St. Vrain River Segment 5, Left Hand Creek: Cu (COSPSV05)
●	Upper Colorado, Eagle River Segment 9a, Eagle River from Ute Creek to Rube 
	Creek: Temperature (COUCEA09a)
●	Upper Colorado, Eagle River Segment 9a, Eagle River from Berry Creek to Squaw 
	Creek: Sediment (COUCEA09a)
●	Upper Colorado, North Platte Segment 9, Lake John: D.O. (COUCNP09)
●	Upper Colorado, Upper Colorado Segment 2, Willow Creek Reservoir: Mn (COUCUC02)
The following segments or parameters were added to the M&E List where there is a reason to suspect water quality problems, but there is also uncertainty.:
●	Arkansas River, Fountain Creek Segment 2a, Fountain Creek: Fe(Trec)
●	Gunnison River, Lower Gunnison Segment 3, Eggleston Reservoir: pH, Zn, Fe(Trec) 
	(COGULG03)
●	Gunnison River, Lower Gunnison Segment 4a, Callow Creek: E. coli (COGULG04a)
●	Gunnison River, Lower Gunnison Segment 4a, Peach Valley Creek: Fe(Trec) 
	(COGULG04a)
●	Gunnison River, Lower Gunnison Segment 4a, Wells Gulch: pH (COGULG04a)
●	Gunnison River, Lower Gunnison Segment 7, Ward Creek: Se (COGULG07)
●	Gunnison River, Lower Gunnison Segment 7, Surface Creek: Pb (COGULG07)
●	Gunnison River, Lower Gunnison Segment 12, Muddy Creek: E. coli (COGULG12)
●	Gunnison River, North Fork Gunnison Segment 4, East Muddy Creek: Pb, Se 
	(COGUNF04)
●	Gunnison River, North Fork Gunnison Segment 4, Muddy Creek: E. coli (May-Oct) 
	(COGUNF04)
●	Gunnison River, North Fork Gunnison Segment 4, Island Reservoir: pH, Zn (COGUNF04)
●	Gunnison River, North Fork Gunnison Segment 5, Leroux Creek: E. coli (COGUNF05)
●	Gunnison River, North Fork Gunnison Segment 6a, Unnamed Tributary: Se 
	(COGUNF06a)
●	Gunnison River, North Fork Gunnison Segment 6b, Alum Gulch: Fe(Trec) (COGUNF06b)
●	Gunnison River, North Fork Gunnison Segment 7, Paonia Reservoir: Zn (COGUNF07)
●	Gunnison River, San Miguel Segment 2, Bear Creek: Pb (COGUSM02)
●	Gunnison River, San Miguel Segment 2, Cornet Creek: Pb (COGUSM02)
●	Gunnison River, San Miguel Segment 3b, San Miguel River: Pb (COGUSM03b)
●	Gunnison River, San Miguel Segment 4a, San Miguel River: Pb (COGUSM04a)
●	Gunnison River, San Miguel Segment 7a, Chapman Creek: Fe(Trec) (COGUSM07a)
●	Gunnison River, San Miguel Segment 7a, Iron Bog Creek: pH, D.O. (COGUSM07a)
●	Gunnison River, San Miguel Segment 10, Naturita Creek:  E. coli, D.O. (COGUSM10)
●	Gunnison River, San Miguel Segment 12, Mesa Creek: Se (COGUSM12)
●	Gunnison River, San Miguel Segment 12, Calamity Draw: D.O. (COGUSM12)
●	Gunnison River, San Miguel Segment 12, Specie Creek: D.O. (COGUSM12)
●	Gunnison River, Upper Gunnison Segment 4, Taylor River: Pb (COGUUG04)
●	Gunnison River, Upper Gunnison Segment 10, Redwell Creek: pH (COGUUG10)
●	Gunnison River, Upper Gunnison Segment 15, S. Beaver Creek: Fe(Trec) (COGUUG15)
●	Gunnison River, Upper Gunnison Segment 16, Ohio Creek: E. coli (COGUUG16)
●	Gunnison River, Upper Gunnison Segment 17, Antelope Creek: E. coli (COGUUG17)
●	Gunnison River, Upper Gunnison Segment 23, Stewart Creek:  Fe(Trec) (COGUUG23)
●	Gunnison River, Upper Gunnison Segment 26, Mesa Creek:  Cu (COGUUG26)
●	Gunnison River, Upper Gunnison Segment 31, Palmetto Gulch:  Ag (COGUUG31)
●	Gunnison River, Uncompahgre Segment 2, Uncompahgre River: Pb (COGUUN02)
●	Gunnison River, Uncompahgre Segment 3b, Ridgway Reservoir: Pb, Zn (COGUUN03b)
●	Gunnison River, Uncompahgre Segment 4c, Uncompahgre River: Pb (COGUUN04c)
●	Gunnison River, Uncompahgre Segment 7, Gray Copper Gulch: pH (COGUUN007)
●	Gunnison River, Lower Dolores Segment 2, Dolores River: E. coli (COGULD02)
●	Gunnison River, Lower Dolores Segment 3a, Disappointment Creek: Se, E. coli 
	(COGULD03a)
●	Gunnison River, Lower Dolores Segment 4, West Paradox Creek: E. coli, Fe(Trec) 
	(COGULD04)
●	Gunnison River, Lower Dolores Segment 5, Roc Creek:  E. coli (COGULD05)
●	Lower Colorado, Lower Colorado Segment 4b, South Canyon Hot Springs:  Pb 
	(COLCLC04b)
●	San Juan/Dolores Rivers, Animas and Florida Segment 3c, Arrastra Gulch:  Pb 
	(COSJAF03c)
●	San Juan/Dolores Rivers, Animas and Florida Segment 12a, Electra Reservoir:  Ag, Zn 
	(COSJAF12a)
●	San Juan/Dolores Rivers, Animas and Florida Segment 13a, Junction Creek:  Ag, E. coli 
	(COSJAF13a)
●	San Juan/Dolores Rivers, Upper Dolores Segment 11, Lost Canyon Creek:  E. coli 
	(COSJDO11)
●	San Juan/Dolores Rivers, La Plata Segment 3a, Cherry Creek:  Cu (COSJLP03a)
●	San Juan/Dolores Rivers, La Plata Segment 4a, E. Mancos River:  Pb (COSJLP04a)
●	San Juan/Dolores Rivers, La Plata Segment 4a, Mancos River:  Cu, Pb (COSJLP04a)
●	San Juan/Dolores Rivers, La Plata Segment 8a, Tribs to McElmo Creek:  E. coli 
	(COSJLP08a)
●	San Juan/Dolores Rivers, Piedra Segment 5, Williams Creek Reservoir: pH, Zn, 
	Fe(Trec), D.O. (COSJPI05)
●	San Juan/Dolores Rivers, Piedra Segment 8a, Williams Creek:  pH, Cu (COSJPI05)
●	San Juan/Dolores Rivers, Piedra Segment 6a, Stollsteimer Creek:  Fe(Trec), E. coli 
	(COSJPI06a)
●	San Juan/Dolores Rivers, San Juan Segment 1, Navajo River:  E. coli (COSJSJ01)
●	San Juan/Dolores Rivers, San Juan Segment 5, San Juan River:  Pb, (COSJSJ05)
●	San Juan/Dolores Rivers, San Juan Segment 6a, San Juan River:  Pb, Cu (COSJSJ06a)
●	San Juan/Dolores Rivers, San Juan Segment 6a, Echo Canyon Reservoir:  pH 
	(COSJSJ06a)
●	San Juan/Dolores Rivers, San Juan Segment 9a, Rio Blanco: Ag, Pb (COSJSJ09a)
●	San Juan/Dolores Rivers, San Juan Segment 10, Rito Blanco:  E. coli (COSJSJ10)
●	South Platte, Upper South Platte Segment 17a, Rocky Mountain Lake: Cu, DO 
	(COSPUS17a)
●	South Platte, Upper South Platte Segment 23, Huston Lake: E. coli (COSPUS23)
●	Upper Colorado, Eagle River Segment 9a, Eagle River from Berry Creek to Ute Creek: 
	Temperature (COUCEA09a)
●	Upper Colorado, Eagle River Segment 9a, Eagle River from Gore Creek to Berry Creek 
	and  from Squaw Creek to Rube Creek: Sediment (COUCEA09a)
●	Upper Colorado, Upper Colorado Segment 10c, Fraser River:  Pb (COUCUC10c)
11. 	Segments Moved to the 303(d) List
As additional water quality data is collected and assessed, a segment may be moved from the M&E List to the 303(d) List once the non-attainment is confirmed. In general, segments with less than 10 data points will be placed on the M&E List until more data is collected. The following segments and parameters have been moved from the M&E List to the 303(d) List due to additional data collection:
●	Arkansas, Upper Arkansas Segment 10, Twin Lake West Cu (COARUA10)
●	Gunnison, Lower Gunnison Segment 7, Tongue Creek: Se (COGULG07)
●	Gunnison, Uncompahgre Segment 9, Sneffels Creek: Zn (COGUUN09)
●	Lower Colorado, White River Segment 11, Rio Blanco Reservoir: pH (COLCWH11)
●	South Platte, Boulder Creek Segment 9, Boulder Creek: Aquatic Life Use (COSPBO09)
●	South Platte, Big Thompson Segment 11, Carter Lake: As (COSPBT11)
●	South Platte, Big Thompson Segment 16, Lake Estes: Pb (COSPBT16)
●	South Platte, Cache la Poudre Segment 14, Horsetooth Reservoir: Cu, As (COSPCP14)
●	South Platte, Lower South Platte Segment 3, Jackson Reservoir: pH (COSPLS03)
●	South Platte, Middle South Platte Segment 4, Barr Lake: D.O. (COSPMS04)
●	South Platte, Middle South Platte Segment 7, Horse Creek Reservoir: D.O. (COSPMS07)
●	South Platte, St. Vrain Segment 3, St. Vrain Creek from Left Hand Creek confluence to 
	confluence with Boulder Creek: Aquatic Life Use (COSPSV03)
●	South Platte, Upper South Platte Segment 17a, Rocky Mountain Lake: pH, Cu 
	(COSPUS17a)
●	South Platte, Upper South Platte Segment 17a, Ferril Lake, Smith Lake: pH 
	(COSPUS17a)
●	South Platte, Upper South Platte Segment 17a, Duck Lake: pH, NH3 (COSPUS17a)
●	South Platte, Upper South Platte Segment 23, Aqua Golf, Overland, Parkfield, and 
	Huston Lakes: pH (COSPUS23)
●	South Platte, Upper South Platte Segment 23, Vanderbilt Lake: DO (COSPUS23)
12.	E. coli Listings
In June of 2010, the Commission adopted a two-month averaging period for the existing E. coli criteria. Evaluation of the E. coli standard is over fixed two-month intervals.  Where adequate data were available two-month intervals were assessed.  Where adequate data were not available data were assessed either seasonally or for the entire period of record.
13. 	Lakes and Reservoirs D.O. (temperature) listings
For lakes and reservoirs, the MWAT is assumed to be equivalent to the maximum WAT. When a lake or reservoir is stratified, the upper portion may exceed the applicable temperature standards in the basin regulations, provided that an adequate refuge exists in water below the upper portion. Adequate refuge depends on concurrent attainment within a given profile of the temperature standard and applicable dissolved oxygen standards. Attainment of the temperature standard below the upper portion is based on comparison with individual depths because of the need to verify concurrent attainment with the DO standard. If the refuge is not adequate because of low dissolved oxygen levels, the lake or reservoir will be listed as impaired for dissolved oxygen rather than for temperature.
14.	Site-specific decisions made by the Commission are discussed below.
Eagle River Segments 6, 8 and 9a: 
The Division originally proposed to list the following segments in the Eagle River Basin:  the mainstem of Eagle River Segment 9a for sediment, temperature, and Aquatic Life Use impairment, and several tributaries to the Eagle River for impairment of the Aquatic Life Use (Provisional) including Black Gore Creek, Beaver Creek, Lake Creek, Red Sandstone Creek and Gore Creek.  Division staff worked with stakeholders in the Eagle River watershed to examine the data and further narrow the issues potentially in dispute.  Through this work additional data was made available.  Based upon the additional data received and reviewed by Division staff, the Division revised its proposal.  In general, parties agreed with the Division’s refined proposal for the Aquatic Life Listings in the Eagle River Subbasin.  Eagle River stakeholders opposed the Division’s proposal to list the mainstem of the Eagle River (Segment COUCEA09a) for temperature.  They presented an alternative proposal to M & E list a 6-mile long portion of the segment from Berry Creek to Ute Creek.  Evidence presented by the Eagle River Water & Sanitation District showed that the only temperature excursions in this stream reach occurred in the early part of the winter shoulder season and wastewater effluent did not cause the excursions.  The District will continue collecting data and will work with the Division to complete additional analysis to determine whether the temperature excursions are a result of anthropogenic activities in the watershed.  The Commission adopted the Eagle River Basin stakeholders’ proposal.
Upper Colorado River Segment 3 (COUCUC03): 
Trout Unlimited referenced a report prepared by the Division of Parks and Wildlife (Nehring 2011) which contained significant site-specific macroinvertebrate and other aquatic life information and analysis for the portion of the Colorado River mainstem between Windy Gap Reservoir and its confluence with the Blue River.  The Commission finds that given the fact that there are conflicting MMI scores on this segment, said portion of this segment should be placed on the Monitoring and Evaluation list at this time.
Western Resource Advocates White River Basin:
WRA proposed the addition of White River Segments COLCWH13b, COLCWH13c, COLCWH14a, COLCWH14b, COLCWH15 and COLCWH20 on either the 303(d) or M&E Lists for selenium (COLCWH13b) or total recoverable iron. Following additional data that was submitted by Shell in its Responsive Prehearing Statement, WRA modified its proposal.  WRA supported listing a portion of COLCWH13b, Duck Creek, on the 303(d) List for selenium.  However, the Commission agreed with the Division that the 2008 Statement of Basis and Purpose language in Regulation #37, Classifications and Numeric Standards for the Lower Colorado River Basin, identifies that the four sites used to create the ambient selenium standard should be assessed in aggregate. The Commission supports the Division’s position to include COLCWH13c and a portion of COLCWH14a (the mainstem Piceance Creek from Willow Creek to Hunter Creek) for inclusion on the 303(d) List for total recoverable iron.
Southwestern Water Conservation District E. coli:
The Commission has placed several stream segments (COGULD02, COGULD03a, COGULD04, COGULD05, COSJAF13a, COSJDO11, COSJLP08a, COSJPI06a, COSJSJ10, and COSJSJ03) on the M&E List for E. coli based on data from four or fewer measurements as outlined in the Listing Methodology.  Because of the limited number of data points, the listings were based on either a seasonal or annual geometric mean, rather than the two-month averaging period. As a result, the Commission has concluded that the data at these sites indicate potential impairment of the E. coli standard, warranting listing on the M&E List so that additional measurements can be collected.
Lower Colorado Segment 3 (COLCLC03):
Lower Colorado Segment 3 was proposed to be removed from the 303(d) List for selenium impairment due to attainment of standards.  USFWS opposed its removal from the list because the segment is critical habitat for the endangered Colorado pikeminnow and razorback sucker.  The Commission acknowledges the significance of this issue, but given the fact that the segment is in attainment of its selenium standard, the segment should be removed from the list.  If the USFWS feels that the standard is not protective of endangered fish species, the Commission recommends they pursue an alternative standard in the next Colorado basin rulemaking hearing.
Animas River (COSJAF05a):
La Plata Energy Council expressed concern with listing segment COSJAF05a as impaired for manganese.  In segment COSJAF05a there is an actual water supply use in the upper portion of the segment.  However, there is no actual water supply use in the lower reach below the intake to the Animas-La Plata Project.  In 2000, when the Commission adopted the table value criteria for manganese based on secondary water supply standards, the Commission adopted Statement of Basis and Purpose language in Section 31.37(iv)(H) indicating that its action could result in the situation facing La Plata – that is, a segment with a water supply classification but where the only actual water supply use is upstream of point source dischargers.  The Commission determined in 2000 that the appropriate course of action is for the Commission to consider resegmentation of that stream.  Accordingly the Commission encourages La Plata to pursue resegmentation in the Regulation #34 basin rulemaking hearing if they believe it is warranted.
Marston Forebay (COSPUS22 or COSPBE11):
Marston Forebay was listed as Segment COSPUS22 in the 2010 version of Regulation #93, when in fact, it is correctly included in COSPBE11.  Marston Forebay was originally placed on the M&E List in 2010 because dissolved oxygen (DO) concentrations were below the standard in the metalimnion (middle layer of the reservoir).  In 2010, the DO standard was revised in Regulation 31. The current DO standard only applies to the top 0.5-2 meters of the water column, unless assessing for refuge with regards to the temperature standard. When assessing against the revised standard, Marston is now attaining the DO standard, as DO readings are above 6 mg/L in the top 2 meters of the water column on all dates.  As a result, the Division proposed to remove Marston from the M&E List. The Commission agreed with the Division’s recommendation and removed Marston from the M&E List for this reason. 
Denver Water also requested a finding that Marston is not “waters of the state”.  The Commission believes that a Regulation #38 rulemaking hearing is the appropriate forum in which to consider any formal regulatory conclusion regarding this issue.
Ralston Creek (COSPCL17b):
The Division originally placed Ralston Creek on the 303(d) List for impairment of its Water Supply Use-based uranium standard. Cotter Corporation opposed this listing and its high priority listing due to ongoing cleanup work at the Schwartzwalder Mine Site. The Division recognizes that Cotter Corporation is actively addressing non-attainment of the primary drinking water uranium standard in Ralston Creek, and the Division anticipates continued cooperation during development of a Category 4b Plan.  However, pending revisions to the standard, the Commission finds that COSPCL17b should be retained on the 303(d) List in the interim with a high priority.  
Wildhorse Creek – Segment COARMA04a: 
Bill Thiebaut, District Attorney for the Tenth Judicial District, Colorado submitted an alternative proposal to add selenium to the existing listing for E.coli for Wildhorse Creek.  After review of the data submitted, the Division agreed with the alternative proposal.  Pueblo West opposed this listing as data for the middle portion of the segment attains the ambient based selenium chronic standard of 597 ug/L as well as the ambient based acute standard of 708 ug/L.  It has generally not been the practice of the Commission to 303(d) list the majority of a segment except for a portion in the middle. In addition, there was discussion in regards to the appropriateness of the adopted ambient based standard.  Pueblo West has expressed interest in reviewing this standard in a future rulemaking hearing. Until revisions to the standard can be made, the Commission has added the entire segment to the 303(d) List for selenium. 
Pueblo West raised concerns about whether the current ambient based selenium standard for Middle Arkansas segment 4a is still the appropriate standard.  This issue was discussed and it was determined that revising the ambient based standard based on new data is not appropriate for this rulemaking but could be addressed in the next basin hearing for Regulation #32 in June 2013.  If the ambient based standard is modified during that proceeding, the appropriateness of the 303(d) listing for this segment would be revisited in the next rulemaking hearing for Regulation #93 in December 2013.  The Commission does not expect that the Division would proceed with development of a TMDL between now and the Regulation #32 hearing in June 2013.
PARTIES TO THE RULEMAKING HEARING
1.	Western Resource Advocates
2.	Bill Thiebaut, District  Attorney for the 10th Judicial District
3.	Colorado Division of Parks and Wildlife
4.	Town of Avon
5.	City of Grand Junction
6.	Eagle River Watershed Council Inc
7.	Town of Vail
8.	Shell Frontier Oil and Gas Inc.
9.	Denver Water
10.	Roaring Fork Conservancy
11.	City of Aurora
12.	Northern Colorado Water Conservancy District
13.	City and County of Denver
14.	City of Colorado Springs and Colorado Springs Utilities
15.	Cripple Creek & Victor Gold Mining Co
16.	MillerCoors, LLC
17.	Seneca Coal Company
18.	Tri-State Generation & Transmission Association
19.	Xcel Energy
20.	Eagle County
21.	City of Boulder
22.	Grand County Districts
23.	Gunnison County
24.	Eagle River Water and Sanitation District
25.	Upper Eagle Regional Water Authority
26.	Vail Corporation
27.	Northwest Colorado Council of Governments
28.	Littleton/Englewood Wastewater Treatment Plant
29.	Southeastern Colorado Water Conservancy District
30.	Colorado Department of Transportation
31.	Pitkin County
32.	Upper Gunnison River Water Conservancy District
33.	Metro Wastewater Reclamation District
34.	Bear Creek Watershed Association
35.	Colorado River Water Conservation District
36.	Cotter Corporation (N.S.L.)
37.	Colorado Oil & Gas Association
38.	Gunnison County Stockgrowers Association, Inc.
39.	Trout Unlimited
40.	Pioneer Natural Resources USA, Inc.
41.	XTO Energy, Inc.
42.	U.S. Fish and Wildlife Service
43.	Colorado Petroleum Association
44.	La Plata County Energy Council
45.	Dolores Water Conservancy District
46.	Southwestern Water Conservation District
47.	Pueblo West Metropolitan District
48.	Greeley Water & Sewer Department
49.	City of Pueblo
50.	Environmental Protection Agency
51.	North Front Range Water Quality Planning Association
52.	Board of County Commissioners of Montrose County
53.	Wright Water Engineers, Inc
54.	South Platte Coalition for Urban River Evaluation
55.	Garfield County
56.	Ruedi Water and Power Authority
57.	Vail Recreation District
58.	National Park Service
59.	Town of Norwood, Norwood Water Commission and Norwood Sanitation District