DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT WATER QUALITY CONTROL COMMISSION REGULATION #93 - COLORADO'S SECTION 303(D) LIST OF IMPAIRED WATERS AND MONITORING AND EVALUATION LIST 5 CCR 1002-93 [Editor’s Notes follow the text of the rules at the end of this CCR Document.] _______________________________________________________________________________

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.

Code of Colorado Regulations 1 WBID Segment Portion Colorado’s Clean Water 303(d)

1. Description Monitoring & Act Section Priority Evaluation 303(d)
   1. Parameter(s) Impairment COAR Arkansas River . . . .
      1. Basin COARFO01a Fountain Creek all . E. coli H and tributaries above Monument Creek COARFO02a Fountain Creek, all Fe(Trec) E. coli H Monument Creek to Hwy COARFO02b Fountain Creek all . E.coli (May- H from Hwy 47 to October)

         the Arkansas River COARFO04 All tribs to all . E.coli H Fountain Creek, which are not on National Forest or Air Force Academy Land COARFO04 All tribs to Sand Creek Aquatic Life . .

         Fountain Creek, which are not on National Forest or Air Force Academy Land COARFO06 Monument All (for E. coli . E.coli (May- H Creek from ) October)

         National Forest to Fountain Creek COARFO07a Pikeview Willow Springs . Aquatic Life M Reservoir, Ponds #1 & #2 Use (PCE Willow Springs FCA)

         Ponds #1 and #2 COARLA01a Arkansas River, all . Se, SO 4 L Fountain Creek to Colorado Canal headgate COARLA01b Arkansas River, all . Se L Colorado Canal headgate to John Martin Reservoir Code of Colorado Regulations 2 COARLA01c Arkansas River, all . Se, U L John Martin Reservoir to stateline COARLA04 Apishapa River, Apishapa . Se L Timpas Creek, River, Timpas Lorencito Creek Canyon COARLA04 Apishapa River, Timpas Creek . Fe(Trec) H Timpas Creek, Lorencito Canyon COARLA05b Trinidad Trinidad . Aquatic Life H Reservoir, Long Reservoir Use (Hg Fish Canyon Tissue), D.O.

         Reservoir, and (Temperature)

         Lake Dorothey COARLA07 Purgatoire all Sediment Se L River, I-25 to Arkansas River COARLA09a Mainstem of all . Se L Adobe Creek and Gageby Creek… COARLA09a Mainstem of Horse Creek . Fe(Trec) H Adobe Creek and Gageby Creek… COARLA09a Mainstem of Adobe Creek . E. coli H Adobe Creek and Gageby Creek… COARLA09b Apache Creek, all . Se L Breckenridge Creek, Little Horse Creek, Bob Creek, Wildhorse Creek, Wolf Creek, Big Sandy Creek COARLA09c Rule Creek, As specified to Zn (Rule Fe(Trec), Se L Muddy Creek, right Creek) (Chicosa Caddoa Creek, Creek)

         Clay Creek, Cat Creek… Code of Colorado Regulations 3 COARLA10 Two Buttes Adobe Creek . Se L Res., Two Res., Nee Buttes Pond, Gronda Res Hasty Lake, Holbrook Res., Burchfield Lake, Nee-Skah (Queens) Res., Adobe Creek Res., Neeso Pah Res., Nee Nosha Res., Nee Gronda Res.

COARLA11 John Martin all . Se L Reservoir COARLA12 Lake Henry, all . Se L Lake Meredith COARMA04a Wildhorse all NO 2 E. coli , Se H/L Creek COARMA06 St. Charles all U Se L River and tributaries, CF&I diversion to Arkansas River COARMA07 Greenhorn all Cu, Zn . .

1. Creek, including all tributiaries, from source to Greenhorn Highline Diversion Dam;
   1. Graneros Creek; North Muddy Creek COARMA09 Greenhorn all Se . .
      1. Creek, including tributaries, from Greenhorn Highline Diversion Dam to the St.

         Charles River COARMA10 Sixmile Creek all . Fe(Trec), Se L COARMA12 Huerfano River, all . Se L from Muddy Creek to the Arkansas River Code of Colorado Regulations 4 COARMA14 Cucharas River, all . Se L from Walsenburg PWS diversion to the outlet of Cucharas Reservoir COARMA16 Huajatolla Horseshoe . Aquatic Life H Reservoir, Lake Use (Hg Fish Diagre Tissue)

         Reservoir, Walsenburg Lower Town Lake, Horseshoe Lake and Martin Lake (Ohem Lake)

COARMA18a Boggs Creek all . Se, Zn, U H COARUA05 All tributaries to Lake Fork Aquatic Life . .

1. the Arkansas below River from the Sugarloaf Dam source to to the immediately confluence below the with the confluence with Arkansas River Browns Creek COARUA08b Iowa Gulch from all . Cd, Pb, Zn M ASARCO water supply intake to Paddock #1 Ditch (Iowa Ditch)

COARUA10 Mainstem of all, excluding . pH, D.O. H Lake Creek and Twin Lakes all tributaries, Reservoir lakes and reservoirs from source to Arkansas River (including Twin Lakes Reservoir)

COARUA10 Mainstem of Twin Lake . Cu H Lake Creek and West all tributaries, lakes and reservoirs from source to Arkansas River (including Twin Lakes Reservoir)

Code of Colorado Regulations 5 COARUA14b Tributaries to Teller Aquatic Life . .

1. the Arkansas Reservoir Use (Hg Fish River, from Tissue)
   1. Pueblo Reservoir to Colorado Canal headgate COARUA15 Grape Creek De Weese . D.O. H including De Reservoir Weese Res., Texas, Badger, Hayden, Hamilton, Stout and Big Cottonwood Creeks, Newland Creek COARUA20 Fourmile Creek North Fork . As .
      1. and tributaries, Wilson Creek Cripple Creek to below Arkansas River Independence Mine COARUA21a Mainstem of all . Aquatic Life L Cripple Creek (provisional)

         from the source to a point 1.5 miles upstream of the confluence with Fourmile Creek.

COARUA27 Mainstem of Brush Hollow . Aquatic Life H Eightmile Reservoir Use (Hg Fish Creek, including Tissue), D.O.

1. all tributaries, wetlands, lake and reservoirs, from the source to the mouth of Phantom Canyon; Brush Hollow Reservoir COGU Gunnison River . . . .
   1. Basin COGULG02 Gunnison River, all Sediment E. coli H Uncompahgre River to Colorado River COGULG03 All tributaries to the Eggleston pH, Zn, Fe(Trec) H Gunnison River which Reservoir are on national forest lands from the outlet of Crystal Reservoir to the confluence with the Colorado River, Code of Colorado Regulations 6 COGULG04a Tributaries to Gunnison Callow Creek SO 4 , E. . . River, Crystal coli Reservoir to Colorado River COGULG04a Tributaries to Gunnison Cummings Gulch SO 4 . . River, Crystal Reservoir to Colorado River COGULG04a Tributaries to Gunnison Whitewater . SO 4 , Mn L River, Crystal Creekfrom below (WS)
      1. Reservoir to Colorado Brandon Ditch to River confluence with Gunnison River COGULG04a Tributaries to Gunnison Wells Gulch pH . .

         River, Crystal Reservoir to Colorado River COGULG04a Tributaries to Gunnison Peach Valley Fe(Trec), . . River, Crystal Creek SO 4 Reservoir to Colorado River COGULG04b All lakes and reservoirs Kannah Creek SO 4 . . tributary to the Gunnison River and not on national forest lands from the outlet of Crystal Reservoir to the Colorado River COGULG04b All lakes and reservoirs Jatz Bottomlands Se . . tributary to the Gunnison River and not on national forest lands from the outlet of Crystal Reservoir to the Colorado River COGULG07 Surface, Ward, Tongue Creek . Se, Fe(Trec) M Tongue, Youngs, and Kiser Creeks not on USFS land COGULG07 Surface, Ward, Ward Creek Se . .

         Tongue, Youngs, and Kiser Creeks not on USFS land COGULG07 Surface, Ward, Surface Creek Pb . .

         Tongue, Youngs, and Kiser Creeks not on USFS land COGULG09 Fruitgrowers Reservoir all . D.O. H COGULG11a Tributaries to the Smith Lunch Creek sediment . . Fork COGULG12 All tributaries to the Muddy Creek E. coli . . Smith Fork which are not on national forest lands Code of Colorado Regulations 7 COGULG13 Crawford Reservoir all . D.O. H (Temperature)

COGUNF04 All tributaries to the East Muddy Pb, Se Fe(Trec) H North Fork of the Creek Gunnison River Muddy Creek to Coal Creek;

1. all tributaries to the North Fork of the Gunnison including the Grand Mesa Lakes which are on national forest lands COGUNF04 All tributaries to the Muddy Creek E. coli . . North Fork of the (May-Oct)
   1. Gunnison River Muddy Creek to Coal Creek;
      1. all tributaries to the North Fork of the Gunnison including the Grand Mesa Lakes which are on national forest lands COGUNF04 All tributaries to the Island Reservoir pH, Zn . . 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 COGUNF06a Tributaries to N. Fork Unnamed Se . .

         of Gunnison River not tributary to North on USFS property Fork Gunnsion River near Hotchkiss COGUNF06a Tributaries to the North Coal Gulch, Fe(Trec) . . Fork of the Gunnison Hawksnest not on USFS lands Creek, Gribble Gulch COGUNF06b Bear Creek, Reynolds Cottonwood Fe(Trec), . . Creek, Bell Creek, Creek Mn(WS), McDonald Creek, SO 4 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 Code of Colorado Regulations 8 COGUNF06b Bear Creek, Reynolds Alum Gulch Fe(Trec) SO 4 M 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 COGUNF07 Paonia Reservoir all Zn . .

COGUSM02 Tributaries to the San Bear Creek Pb Cd, Zn(sc) H Miguel River from the source to Leopard Creek COGUSM02 Tributaries to the San Cornet Creek Pb . .

1. Miguel River from the source to Leopard Creek COGUSM02 Tributaries to the San Howard Fork . pH, D.O. H Miguel River from the above Swamp source to Leopard Canyon Creek COGUSM03b Mainstem of the San all Pb . .
   1. Miguel River Marshall Creek to South Fork San Miguel River.

COGUSM04a Mainstem of the San From South Fork Pb . .

1. Miguel River from the San Miguel to South Fork of the San confluence with Miguel to below the CC Leopard Creek ditch.

COGUSM06a Ingram Creek, source all Mn, Cu . .

1. to San Miguel River COGUSM06b Marshall Creek, source all Cu . .
   1. to San Miguel River COGUSM07a Mainstem of Howard Chapman Creek Fe(Trec) . . Fork and tributaries Swamp Gulch the South Fork of the San Miguel.

COGUSM07a Mainstem of Howard Iron Bog Creek pH, D.O. . . Fork and tributaries Swamp Gulch the South Fork of the San Miguel.

COGUSM08 Mainstem of South all Mn(WS) . .

1. Fork of San Miguel River from the Howard and Lake Forks to the San Miguel River.

Code of Colorado Regulations 9 COGUSM10 Mainstem of Naturita Naturita Creek D.O., E. . . Creek from the coli Uncompahgre National Forest boundary to its confluence with the San Miguel River, and Gurley Reservoir;

1. Tabeguache Creek from its source to the confluence with San Miguel River.

COGUSM11 West Fork of Naturita Miramonte . D.O. H Creek, Miramonte Reservoir (Temperature)

1. Reservoir, the mainstem of Beaver, Horsefly and Saltado Creeks from the Uncompahgre National Forest boundary to their confluence with the San Miguel River.

COGUSM12 All tributaries to the Mesa Creek Se . .

1. San Miguel River from the confluence of Leopard Creek to the Dolores COGUSM12 All tributaries to the Calamity Draw, D.O. . . San Miguel River from Specie Creek the confluence of Leopard Creek to the Dolores COGUSM12 All tributaries to the Maverick Draw . Aquatic Life L San Miguel River from (provisional)
   1. the confluence of Leopard Creek to the Dolores COGUUG04 Mainstem of the Taylor Taylor River Pb . .
      1. River from the source to the confluence with the Gunnison River COGUUG06b Cement Creek and all Cement Creek . Aquatic Life L its tributaries and all (provisional)

         lakes, reservoirs, and wetlands in the East River Drainage tributary to Segment 6a.

COGUUG07 Slate River from Below Oh-Be- . Zn(sculpin) H source to Coal Creek Joyful Creek COGUUG08 Slate River, Coal Creek all Aquatic Cd, Zn H to East River Life COGUUG09 All tributaries to the Coal Creek . As H Slate River Code of Colorado Regulations 10 COGUUG10 Oh-Be-Joyful Creek all . Cd, Cu, Pb, Zn H and tributaries from wilderness to Slate River COGUUG10 Oh-Be-Joyful Creek Redwell Creek pH . .

1. and tributaries from wilderness to Slate River COGUUG11 Coal Creek from Elk Elk Creek . Cd, Pb, Zn, As H Creek to Crested Butte water supply intake, plus Elk Creek COGUUG11 Coal Creek from Elk Coal Creek . Cd, Zn, As, H Creek to Crested Butte Mn(WS)
   1. water supply intake, plus Elk Creek COGUUG12 Coal Creek and Coal Creek . Cd, Zn, Cu H tributaries from Crested Butte water supply intake to Slate River COGUUG15 Tributaries to the S. Beaver Creek Mn (WS), Aquatic Life L Gunnison River from Fe (Dis), (provisional)
      1. the confluence of the Fe(Trec), East and Taylor Rivers to the inlet of Blue Mesa Reservoir COGUUG16 Ohio Creek and Ohio Creek E. coli . .

         tributaries source to Gunnison River COGUUG17 Antelope Creek and all Mn (WS), . .

         tributaries source to E. coli Gunnison River COGUUG23 Mainstem of Stewart Creek Fe(Trec) . .

         Cochetopa Creek and tributaries, from the source to a point immediately below the confluence with West Pass Creek COGUUG23 Mainstem of Cochetopa Creek Fe(Dis) . .

         Cochetopa Creek and tributaries, from the source to a point immediately below the confluence with West Pass Creek COGUUG24 Mainstem of Cochetopa Creek . Aquatic Life L Cochetopa Creek from from Forest Road (provisional)

         West Pass Creek to 3076/Co. Rd. 43 Tomichi Creek to the confluence with Tomichi Creek Code of Colorado Regulations 11 COGUUG26 All tributaries, from the Blue Creek Cu . .

         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 COGUUG29a Lake Fork of the Deadman Creek . pH, Cd, Cu, H Gunnison River and Mn, Zn, Se, Fe tributaries from source (Trec), Fe to Blue Mesa Reservoir (Dis)

COGUUG29a Mainstem of the Lake Lake Fork of the . Mn (WS), H Fork of the Gunnison Gunnison River Aquatic Life and tributaries from the between Cooper (provisional)

1. source to Blue Mesa and Silver Creek Reservoir COGUUG31 Palmetto Gulch all Cu, Ag . .

COGUUG32 North Fork of Henson all . Mn (WS) L Creek and tributaries from source to Henson Creek COGUUN02 Mainstem of the all Pb Mn (WS) L Uncompahgre River from the source at Como Lake to a point immediately above the confluence with Red Mountain Creek.

COGUUN03b Ridgway Reservoir all Pb, Zn . .

COGUUN04a Uncompahgre River, all sediment . .

1. HWY 90 to La Salle Road COGUUN04b Uncompahgre River, all sediment . .
   1. La Salle Road to Confluence Park COGUUN04c Uncompahgre River, all Sediment, Fe(Trec) H Confluence Park to Pb Gunnison River M Mainstem of Red all . Ag, Cu Mountain Creek from the source to immediately above the confluence with the East Fork of Red Mountain Creek.

Code of Colorado Regulations 12 COGUUN07 Gray Copper Gulch all Fe(Trec), Cu M from source to Red pH Mountain Creek COGUUN08 Mineral Creek, source all Cu, Zn . .

1. to Uncompahgre River COGUUN09 Canyon Creek, Sneffels Creek . Cd, Zn H Imogene Creek, Sneffels Creek COGUUN09 Canyon Creek, Canyon Creek Pb . .
   1. Imogene Creek, Sneffels Creek COGUUN10 All tributaries to the Alkali Creek Se . .
      1. Uncompahgre River from Dexter Creek to the South Canal COGUUN11 Coal, Dallas, Cow, Billy Creek, Onion Se . .

         Billy, Onion, Beaton, Creek Beaver and Pleasant Valley Creeks COGUUN11 Coal, Dallas, Cow, Deer Creek . Aquatic Life L Billy, Onion, Beaton, (provisional)

         Beaver and Pleasant Valley Creeks COGUUN11 Coal, Dallas, Cow, Cow Creek SO 4 . .

         Billy, Onion, Beaton, Beaver and Pleasant Valley Creeks COGUUN12 Tributaries to Dry Creek, . Fe(Trec) H Uncompahgre River, Loutzenhizer South Canal to Arroyo Gunnison River COGUUN14 Sweitzer Lake all . Se* H COGUUN15b Dry Creek from East Dry Creek sediment . .

         and West Forks to Watershed Coalbank Canyon Creek COGULD02 Dolores River from all E. coli Fe(Trec) H Little Gypsum Valley bridge to Colorado/Utah border COGULD03a All tributaries to the Disappointment Se, E. . . Dolores River from the Creek coli bridge at Bradfield Ranch to the Colorado/Utah border.

Code of Colorado Regulations 13 COGULD04 Mainstem of West West Paradox E. coli , . .

1. Paradox Creek from Creek Fe(Trec)
   1. the source to the confluence with the Dolores River.
      1. Mainstem and all tributaries to Blue Creek from the source to the confluence with the Dolores River.

COGULD05 Mainstem of West Roc Creek E. coli Cu, Fe(Trec) H 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.

COLC Lower Colorado River . . . .

1. Basin COLCLC01 Colorado River, Roaring all sediment . .
   1. Fork River to Rifle Creek COLCLC02a Colorado River, Rifle Creek all sediment . .
      1. to Rapid Creek COLCLC02b Colorado River, Rapid Creek Humphrey . Se M to Gunnison River Backwater area COLCLC02b Colorado River, Rapid Creek all Sediment . .

         to Gunnison River COLCLC04a Tributaries to Colorado all . Se M River, Roaring Fork to Parachute Creek except for specific segments COLCLC04a Tributaries to Colorado Alkali Creek E.coli , . . River, Roaring Fork to Cu, Parachute Creek Exc. Fe(Trec), specific segments Pb, Zn COLCLC04b South Canyon Hot Springs all D.O., Pb . .

COLCLC04c South Canyon Creek all Cu, Se, E. . .

1. coli (May- Oct)

COLCLC10 East Rifle Creek, West Rifle West Rifle Fe(Trec) . . Creek and Rifle Creek, Creek including tributaries from Rifle Gap to the Colorado River COLCLC10 East Rifle Creek, West Rifle all E.coli Se L Creek and Rifle Creek, including tributaries from Rifle Gap to the Colorado River Code of Colorado Regulations 14 COLCLC13b Tributaries to Colorado River Salt Creek . sediment L from Government Highline Canal Diversion to Salt Creek COLCLC13b Tributaries to Colorado River all . Se M from Government Highline Canal Diversion to Salt Creek COLCLC13b Tributaries to Colorado River Adobe . E.coli , H from Government Highline Creek, Fe(Trec)

1. Canal Diversion to Salt Leach Creek Creek COLCLC13b Tributaries to Colorado Indian Wash Fe(Trec) . . River, Government Highline Canal to Salt Creek Exc.
   1. specific segments COLCLC13c Walker Wildlife Area Ponds all . Se M COLCLC14b Clear Creek from Tom Creek all E.coli , . .
      1. to Roan Creek. Roan Creek, Fe(Trec)

         including tributaries from Clear Creek to Kimball Creek COLCLC14c Mainstem of Roan Creek Dry Fork . Se L including all tributaries from Kimball Creek to the Colorado River COLCLC15 Plateau Creek, including all Fe(Trec), . .

         tributaries from source to Se Hwy 330 Bridge. Kimball Creek, Grove Creek, Big Creek, Cottonwood Creek, Bull Creek, Spring Creek, Coon Creek and Mesa Creek.

COLCLC19 Lakes and reservoirs See Se Se (West H tributary to the Colorado specifics to (Maggio Pond River, Parachute Creek to the right. Pond, Orchard the Colorado/Utah border. Peters Mesa Wildlife Ponds 1, 2, Area)

1. 3, & 4)

COLCLC20 Rifle Gap Reservoir, Harvey Rifle Gap . Aquatic Life H Gap Reservoir and Vega Reservoir Use (Hg Fish Reservoir Tissue)

COLCLY02 Yampa River, Elkhead Creek all sediment Fe(Trec) H to Green River COLCLY03c Milk Creek and tributaries Stinking Cu, . .

1. from CR 15 to the Yampa Gulch Fe(Trec), Se, Zn COLCLY03e Good Spring Creek above Wilson Se . .
   1. Wilson Reservoir Creek COLCLY05 Fortification Creek from all . Se L North and South Fork to the Yampa River Code of Colorado Regulations 15 COLCLY07 Little Bear Creek, including all Cu, Zn . .
      1. all tributaries from source to Dry Creek COLCLY16 Little Snake River from all sediment . .

         Power Wash to the Yampa River COLCLY18 Slater Creek, including all E. coli , Fe . .

         tributaries from source to (Trec),Se Second Creek COLCLY22a Mainstem of Vermillion Talamantes . Aquatic Life L Creek, including all Creek (provisional)

         tributaries and wetlands, from the Colorado / Wyoming border to a point just below the confluence with Talamantes Creek.

COLCLY22c Vermillion Creek from Hwy all E.coli , . .

1. 318 to Green River Fe(Trec)

COLCWH07 Mainstem of the White River White River, Cu . . from a point above the blw Meeker confluence with Miller Creek to a point immediately above the confluence with Piceance Creek COLCWH09a Tributaries to the White Strawberry Cu, Zn . . River from North and South Creek Forks to Piceance Creek not within the boundary of national forest lands except segments 9b and 10b.

COLCWH09d Sulfur Creek and tributaries all . Se L from Source to White River.

1. Flag Creek and tributaries from the East Fork of Flag Creek to the White River COLCWH10b Mainstem of Big Beaver Coal Creek Se . .
   1. 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 COLCWH11 Rio Blanco Reservoir Rio Blanco . pH H Reservoir Code of Colorado Regulations 16 COLCWH13b Mainstem of Yellow Creek Duck Creek Aquatic . . from the source to the Life confluence with Barcus Creek. All tributaries to Yellow Creek from the source to the White River COLCWH13c Mainstem of Yellow Creek All . Fe (Trec), L from immediately below the Aquatic Life confluence with Barcus Creek to the confluence with the White River.

COLCWH14a Mainstem of Piceance Creek Willow . Fe(Trec) H from the source to a point Creek to just below the confluence Hunter with Hunter Creek Creek COLCWH15 Mainstem of Piceance Creek Piceance . Aquatic Life L from Ryan Gulch to the Creek (provisional)

1. confluence with the White River. The Dry Fork of Piceance Creek, from Little Reigan Gulch to Piceance Creek.

COLCWH16 All tributaries to Piceance Ryan Gulch E.coli . . Creek, including all wetlands, lakes and reservoirs, from the source to the confluence with the White River COLCWH20 Mainstems of Black Sulphur Black . Aquatic Life L Creek from the source to Sulphur (provisional)

1. Piceance Creek. Creek COLCWH22 Tributaries to White River, West . sediment L Douglas Creek to Evacuation Colorado/Utah border Wash, Douglas Creek COLCWH23 Mainstem of East Douglas East Fe(Trec) . .
   1. Creek and West Douglas Douglas Creek including all tributaries Creek from their sources to the confluence COLCWH23 Mainstem of East Douglas West . Aquatic Life L Creek and West Douglas Douglas (provisional)
      1. Creek including all tributaries Creek from their sources to the confluence CORG Rio Grande River Basin . . . .

CORGAL02 Alamosa River, from source Tribs to lower . pH, Cu, Zn, H to confl with Alum Creek Iron Ck Fe(Trec)

CORGAL02 Alamosa River, from source All, except for pH, . . to confluence with Alum the tributaries Fe(Trec)

1. Creek to Lower Iron Creek Code of Colorado Regulations 17 CORGAL03b Alamosa River, from Above Jasper Se Cd H Wightman Fork to Fern Creek Creek CORGAL03d Alamosa River, from all . Al H Ranger Creek to Terrace Res.

CORGAL08 Terrace Reservoir all . Fe(Trec) M CORGAL11 La Jara Creek including La Jara pH D.O. H tributaries, wetlands, lakes Reservoir and reservoirs from source to Hot Creek CORGAL13 Hot Creek from source to all . Fe(Trec) H La Jara Creek CORGAL14 Conejos River including Platoro pH . .

1. tributaries, wetlands, lakes, Reservoir and reservoirs from source to Fox Creek CORGAL20 Rio Grande, tribs within the all pH, . .
   1. Rio Grande Forest Cu,Cd, Fe(Trec), Mn, Zn CORGCB02 La Garita Creek, source to La Garita Fe(Trec) . . 38 Rd, Carnero Creek, Creek source to 42 Rd CORGCB05 San Luis Creek, from Piney Lower San Luis D.O. . . Creek to San Luis Lake Creek CORGCB06 San Luis Lake all . NH 3 , H Fe(Trec)

CORGCB08 Kerber Creek, source to Squirrel Creek Cd, Cu, . . abv Cocomongo Mill Site, Zn, Squirrel Creek from source Fe(Trec)

1. to abv Bear Creek. Brewery Creek from source to Elkhorn Gulch CORGRG02 Rio Grande River, source to South Clear Fe(Trec), . . Willow Creek Creek CORGRG04 Rio Grande River, Willow Del Norte to . Cu H Creek to Alamosa County county line line CORGRG05 All tributaries to the Rio Nelson Creek Cd, Cu, . . Grande River, abv Willow Pb, Mn, Creek to Del Norte Zn, pH CORGRG07 West Willow Creek, East Nelson Creek, . pH H Willow Creek, Willow Creek West Willow and tributaries Creek below Nelson Creek to East Willow Creek Code of Colorado Regulations 18 CORGRG12 Mainstem of the Rio all . Aquatic Life L Grande from the Rio (provisional)
   1. Grande/Alamosa County line to the Old State Bridge east of Lobatos (Conejos County Road G).

CORGRG13 Rio Grande River, Conejos all sediment . .

1. County Road G to Colorado/New Mexico border CORGRG27 Smith Reservoir Smith pH . .
   1. Reservoir CORGRG28 Rito Seco, from source to Upper Rito . E.coli H Salazar Reservoir Seco blw Battle Mtn CORGRG30 Culebra Creek, including all Sanchez . D.O. H tributaries, lakes, and Reservoir reservoirs from HWY 159 to the Colorado/New Mexico border COSJ San Juan River Basin . . . .

COSJAF03c Arrastra Gulch including all all Pb Cd, Zn M lakes, tributaries, and wetlands from the source to the confluence with the Animas River.

COSJAF04a Mainstem of the Animas all . Al(Trec) M River from a point immediately above the confluence with Mineral Creek to a point immediately above the confluence with Deer Park Creek.

COSJAF05a Mainstem of the Animas all . Mn(WS) L River, including wetlands, from Bakers Bridge to the Southern Ute Indian Reservation boundary.

COSJAF12a All tributaries to the Animas Electra Ag, Zn . . River, from a point Reservoir 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.

Code of Colorado Regulations 19 COSJAF13a Mainstem of Junction Junction Ag, E. . .

1. Creek including all Creek coli tributaries, from U.S. Forest Boundary to confluence with Animas River.

COSJDO04b McPhee Reservoir and McPhee . Aquatic Life H Summit Reservoir Reservoir Use(Hg* Fish Tissue)

COSJDO11 All tributaries to the Dolores Lost Canyon E. coli . . River, from the confluence Creek of the West Dolores River, to the bridge at Bradfield Ranch (Forest Route 505, near Montezuma/Dolores County Line COSJLP01 Mainstem of the La Plata All . Ag H River, from the source to the Hay Gulch diversion south of Hesperus.

COSJLP03a All Tributaries to the La Cherry Creek Cu Fe(Trec) H Plata River from Hay Gulch to the Southern Ute Indian reservation boundary COSJLP04a Mancos River and E. Mancos Pb Cu,D.O., Mn H tributaries above HWY 160 River (WS)

COSJLP04a Mancos River and Mancos River Cu, Pb D.O., H tributaries above HWY 160 COSJLP07a Mainstem of McElmo Creek McElmo . Fe-Trec, E. H from the source to the Creek coli Colorado/Utah border;

1. Mainstem of Yellow Jacket Creek from the source to the confluence with McElmo Creek.

COSJLP08a Tributaries to McElmo Mud Creek . Se M Creek COSJLP08a Tributaries to McElmo Hartman Fe(Trec) . .

1. Creek Draw COSJLP08a Tributaries to McElmo Trail Canyon . Fe(Trec) M Creek COSJLP08a Tributaries to McElmo all E. coli . .
   1. Creek COSJLP11 Narraguinnep, Puett, and Narraguinnep . Aquatic Life H Totten Reservoir Reservoir, Use(Hg* Fish Totten Tissue)
      1. Reservoir Code of Colorado Regulations 20 COSJPI05 All tributaries to the Piedra Williams pH, Zn, . . River, including all Creek Fe(Trec), wetlands, lakes and Reservoir D.O.

      reservoirs, from the boundary of the Weminuche Wilderness Area to a point immediately below the confluence with Devil Creek. Williams Creek Reservoir.

COSJPI05 All tributaries to the Piedra Williams pH, Cu . . River, from the boundary of Creek the Weminuche Wilderness Area to the confluence with Devil Creek. Williams Creek Reservoir.

COSJPI06a Tributaries to the Piedra Stollsteimer Sediment, . . River Creek above E. coli , Southern Ute Fe(Trec), Boundary SO 4 COSJPN03 Vallecito Reservoir Vallecito . Aquatic Life H Reservoir Use (Hg Fish Tissue)

COSJSJ01 Mainstem of the Navajo Navajo River E. coli . . River and the Little Navajo River from the boundary of the South San Juan Wilderness Area to the Colorado/New Mexico border COSJSJ03 Little Navajo River, all E.coli . .

1. including tributaries from the San Juan-Chama diversion to the San Juan River COSJSJ05 Mainstem of the San Juan Mainstem Pb . .
   1. 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 COSJSJ06a San Juan River from San Juan Pb, Cu . .

      Fourmile Creek to Southern River Ute Indian Reservation. Mill Creek from source to San Juan River. Echo Canyon Reservoir.

Code of Colorado Regulations 21 COSJSJ06a San Juan River from Echo Canyon pH D.O. H Fourmile Creek to Southern Reservoir (Temperature)

1. Ute Indian Reservation. Mill Aquatic Life Creek from source to San Use (Hg Fish Juan River. Echo Canyon Tissue)
   1. Reservoir.

COSJSJ08 Navajo Reservoir Navajo Aquatic . .

1. Reservoir Life Use (Hg Fish Tissue)

COSJSJ09a Mainstem of the Rio Blanco . Ag, Pb . .

1. from the boundary of South San Juan Wilderness Area to the Southern Ute Indian Reservation boundary, COSJSJ10 Mainstem of the Rito . E. coli . .
   1. Blanco River from Echo Ditch to the confluence with the Rio Blanco River.

COSP South Platte . . . .

1. River Basin COSPBD01 Mainstem of Big all . E. coli , Se (4/1 H/L Dry Creek, thru 10/31)
   1. including all tributaries, lakes, reservoirs and wetlands, from the source to the confluence with the South Platte River COSPBE01 Mainstem of Bear Witter . Temperature, H a Creek from the Gulch to Aquatic Life boundary of the inlet of (provisional)
   2. Mt. Evans Evergreen Wilderness area to Lake the inlet of Evergreen Lake.

COSPBE01c Bear Creek all . Chl-a, H Reservoir phosphorus COSPBE01 Mainstem of Bear All Aquatic Life . .

e Creek from the outlet of Evergreen Lake to the Harriman Ditch.

COSPBE01 Mainstem of Bear From the . Temperature H e Creek from the outlet of outlet of Evergreen Evergreen Lake to Lake to the Harriman Kerr/Swede Ditch. Gulch Code of Colorado Regulations 22 COSPBE02 Bear Creek below Below Aquatic Life E.coli (May-Oct) H Bear Creek Kipling Reservoir to South Parkway Platte River (CO 390)

COSPBE05 Swede, Kerr, Swede/Kerr . E.coli L Sawmill, Gulch Troublesome and Cold Springs Gulches and Cub Creek COSPBO01 All tribs to Boulder all Pb, Zn . .

1. Creek within the Indian Peaks Wilderness Area COSPBO02 Mainstem of all Cd, Cu . .

a Boulder Creek,from the boundary of the Indian Peaks Wilderness Area to a point immediately below the confluence with North Boulder Creek COSPBO02 Boulder Creek, all Cd, Cu . .

b from below the confluence with North Boulder Creek to above the confluence with South Boulder Creek COSPBO03 Mainstem of all Cd, Cu . .

1. Middle Boulder Creek from source to the outlet of Barker Reservoir COSPBO07 Coal Creek, HWY all Aquatic Life E. coli H b 36 to Boulder Creek COSPBO08 All tribs to South Rock Creek E. coli , Se M Boulder Creek and all tribs to Coal Creek COSPBO09 Mainstem of all Cd, As . .
   1. Boulder Creek, from South Boulder Creek to Coal Creek COSPBO09 Mainstem of From 107th . Aquatic Life L Boulder Creek, Street to the (provisional)

      from South confluence Boulder Creek to with Coal Coal Creek Creek Code of Colorado Regulations 23 COSPBO10 Boulder Creek, all Aquatic E. coli H Coal Creek to St. Life, Cd Vrain Creek COSPBO14 Lakes and Barker Cd, Cu . .

      reservoirs tributary Reservoir to Boulder Creek from source to South Boulder Creek.

COSPBO15 South Boulder Gross Aquatic Life . .

1. Creek and Reservoir Use (Hg tributaries from Fish Tissue)
   1. source to outlet of Gross Reservoir COSPBT01 Mainstem of the All . Cu H Big Thompson River, including all tributaries and wetlands, within Rocky Mountain National Park.

COSPBT02 Big Thompson Fish Creek . pH H River and tribs, below RMNP to Home Marys Lake Supply Canal diversion COSPBT02 Big Thompson all Sulfide Cu, Cd, Zn, H River and tribs, temperature RMNP to Home Supply Canal diversion COSPBT03 Mainstem of the All . Cu M Big Thompson River from the Home Supply Canal diversion to the Big Barnes Ditch diversion.

COSPBT04a Mainstem of the All . Se M Big Thompson from the Big Barnes Ditch diversion of the Greeley-Loveland Canal diversion.

COSPBT04b Big Thompson all . Se M River, Greeley- Loveland Canal diversion to CR11H COSPBT05 Big Thompson all . Se L River, I-25 to S.

1. Platte River Code of Colorado Regulations 24 COSPBT06 All tributaries to All . Cu M the Big Thompson River, from Home Supply Canal to the confluence with the South Platte River.

COSPBT06 All Tribs to the Big Dry Creek E. Coli . .

1. Thompson River, from Home Supply Canal to the confluence with the South Platte River.

COSPBT07 Mainstem of the North Fork . Cu H North Fork of the of Big Big Thompson Thompson from RMNP to confluence with Big Thompson COSPBT08 Mainstem of the All . Temperature, D.O H Little Thompson River, from source to the Culver Ditch diversion.

COSPBT08 Mainstem of the From . SO 4 H Little Thompson source to River, from source St. Vrain to the Culver Ditch Supply diversion. Canal COSPBT09 Little Thompson all . Cu, Se, E. coli M/L/H/ River, Culver Ditch (May-October), M to Big Thompson Aquatic Life Use River COSPBT10 Tributaries To the Big Hollow . Se L Little Thompson River COSPBT11 Carter Lake all . Aquatic Life Use H (Hg Fish Tissue), As COSPBT12 Lake Loveland, Boyd Lake . Aquatic Life Use H Horseshoe Lake, (Hg Fish Tissue)

1. Boyd Lake COSPBT14 Welch Reservoir, Lonetree Aquatic Life . .
   1. Lonetree Reservoir Use (Hg Reservoir, Fish Tissue)

      Boedecker Lake, Lon Hagler Reservoir Code of Colorado Regulations 25 COSPBT16 Lakes and Lake Estes . Cu, Pb H reservoirs tributary to the Big Thompson from RMNP to Home Supply Canal diversion.

COSPCH03 Mainstem of All . E.coli , Se H/L Cherry Creek from Cherry Creek Reservoir to the South Platte.

COSPCH03 Mainstem of From Holly . Fe(Trec) M Cherry Creek from Street to Cherry Creek South Platte Reservoir to the confluence South Platte.

COSPCH04 Tributaries to Goldsmith . Se L Cherry Creek Gulch, Cottonwood Creek COSPCH06 Lakes and Lollipop Se D.O. M reservoirs in the Lake Cherry Creek watershed within the City and County of Denver.

COSPCL01 Mainstem of Clear Kearney Aquatic Life . .

1. Creek, including Gulch, all tributaries and Grizzly wetlands, from the Gulch source to the I-70 bridge above Silver Plume.

COSPCL02a Mainstem of Clear All . Cd H Creek from Silver Plume to West Fork Clear Creek.

COSPCL02b Mainstem of Clear All . Cd, Zn H Creek from West Fork Clear to Mill Creek.

COSPCL02c Mainstem of Clear All . Cd H Creek from Mill Creek to Argo Tunnel.

COSPCL03a Mainstem of S. all . Cu H Clear Creek COSPCL03b Leavenworth all . Cu M Creek COSPCL06 West Clear Creek Mad Creek pH Zn M tributaries COSPCL06 All tributaries to Hoop Creek Cd, Pb, Zn . .

1. West Clear Creek.

Code of Colorado Regulations 26 COSPCL09a Fall River & Fall River Zn, D.O. . .

1. tributaries, source to Clear Creek COSPCL09a Fall River & Silver Creek . Cu, Pb H tributaries, source to Clear Creek COSPCL09b Trail Creek & all . Cd, pH H tributaries, source to Clear Creek COSPCL11 Clear Creek, Argo all . Cd H Tunnel to Farmers Highline Canal COSPCL13b N. Clear Creek & Mainstem of . Cd M tributaries, lowest N. Clear water supply Creek intake to Clear Creek COSPCL14a Mainstem of Clear From Croke . Aquatic Life L Creek from the Canal (provisional)
   1. Farmers Highline Diversion to Canal diversion in McIntyre Golden, Colorado Street to the Denver Water conduit #16 crossing.

COSPCL14b Clear Creek, all Mn Aquatic Life Use, L Denver Water organic sediment, conduit #16 to Youngfield St.

COSPCL15 Clear Creek, all Pb E. coli (May- H/L/L Youngfield St. to October), Aquatic

1. S. Platte River Life Use, organic sediment, Mn (WS)

COSPCL17a Arvada Reservoir all . D.O.(Temperature H )

COSPCL17b Mainstem of all . U H Ralston Creek, including all tributaries and wetlands, from the source to the inlet of Arvada Reservoir.

COSPCL18a Ralston Creek and Ralston . E. coli H tributaries below Creek Arvada Reservoir COSPCP06 Mainstem of the all Cu . .

1. North Fork of the Cache La Poudre River, including all tribs from source to Halligan Res.

Code of Colorado Regulations 27 COSPCP07 North Fork of the all . Pb, Cd M Cache la Poudre from Halligan Reservoir to the Cache la Poudre.

COSPCP08 All tributaries to all E. coli . .

1. the North Fork of the Cache La Poudre from Halligan Reservoir to the Cache La Poudre.

COSPCP09 Rabbit Creek and all Cd, Pb . .

1. Lone Pine Creek COSPCP10 Cache la Poudre all . Cu, Temperature M River, Monroe Canal to Shields Street COSPCP11 Mainstem of the all . Se L Cache la Poudre River from Shields Street in Ft.
   1. Collins to a point immediately above the confluence with Boxelder Creek.

COSPCP12 Cache la Poudre all . Se, E. coli (May- L/H River, Box Elder October)

1. Creek to S. Platte River COSPCP13 All tributaries to all . Se L a the Cache la Poudre River, including all wetlands, from the Monroe Gravity Canal to the confluence with the South Platte River.

COSPCP13 All tributaries to Spring . E.coli , (May-Oct) H a the Cache la Creek and Poudre River, Fossil including all Creek wetlands, from the Monroe Gravity Canal to the confluence with the South Platte River.

COSPCP13 Boxelder Creek all . Se L b from source to the Cache la Poudre River Code of Colorado Regulations 28 COSPCP14 Horsetooth all . Aquatic Life Use H Reservoir (Hg Fish Tissue), Cu, As COSPCP20 Lakes and Seaman . D.O. M reservoirs tributary Reservoir to the North Fork of the Cache la Poudre from Halligan Reservoir to the Cache la Poudre River.

COSPLA02a Mainstem of all pH . .

1. Laramie River from the source to the NF boundary.

COSPLS01 Mainstem of the all Aquatic Life Se, Mn M South Platte from Use the Weld/Morgan County line to the Colorado/Nebrask a border.

COSPLS02b Tributaries to S Beaver . Se, E. coli H Platte River, Creek Beaver Creek, Bijou Creek and Kiowa Creek COSPLS03 Jackson, Prewitt, North D.O. . .

1. North Sterling, Sterling Jumbo, Riverside, Empire and Vancil Reservoirs COSPLS03 Jackson, Prewitt, North Se . .
   1. North Sterling, Sterling, Jumbo, Riverside, Jackson Empire and Vancil and Jumbo Reservoirs Reservoirs COSPLS03 Jackson, Prewitt, Jackson . pH H North Sterling, Reservoir Jumbo, Riverside, Empire and Vancil Reservoirs COSPMS01 South Platte River all . E.coli H a from Big Dry Creek to St. Vrain Creek COSPMS01 South Platte River all . Se L b from St. Vrain Creek to Weld/Morgan County Line COSPMS04 Barr Lake and Milton . D.O., pH, NH 3 , M/L Milton Reservoir Reservoir COSPMS04 Barr Lake and Barr Lake . pH, D.O. M Milton Reservoir Code of Colorado Regulations 29 COSPMS07 All lakes and Horse . pH, NH 3 , D.O. L reservoirs trib to Creek the South Platte Reservoir River below Big Dry Creek to Weld/Morgan County Line COSPMS07 All lakes and Prospect . D.O., pH, NH 3 M reservoirs in Lake watershed tributary to the South Platte from Chatfield to Big Dry Creek.

COSPRE04 Mainstem of all . E.coli H Arikaree River from the confluence of the North and South Forks to the Kansas border.

COSPRE05 Mainstem of the all E. coli , Se . .

1. Black Wolf Creek from the source to the confluence with the Arikaree River.

COSPSV02 Mainstem of St. all . Zn H a Vrain from Indian Peaks Wilderness Area and RMNP to eastern boundary of Roosevelt Ntl Forest COSPSV02 St. Vrain Creek, all . Cu, Temperature H b RMNP to Hygiene Road COSPSV03 St. Vrain Creek, From the . Aquatic Life Use L Hygiene Rd. to S. confluence (provisional)

1. Platte River with Left Hand Creek to the confluence with Boulder Creek COSPSV03 St. Vrain Creek, From Hover Aquatic Life . .
   1. Hygiene Rd. to S. Road to the Use, Platte River confluence with Left Hand Creek COSPSV04 Left Hand Creek, (Hwy 72 to . pH, Cu, Zn M a from source to blw James Ck);

      confluence with James Creek Code of Colorado Regulations 30 COSPSV04 James Creek, Little James . Cu, Pb M b Little James Creek Creek COSPSV04c Left Hand Creek all . Cu, As H from James Creek to HWY 36 COSPSV05 Mainstem of Left Upstream . Mn (WS) L Hand Creek, Lefthand including all Feeder tributaries and Canal wetlands from Highway 36 to the confluence with St.

      Vrain Creek.

COSPSV05 Mainstem of Left Downstrea . Cu M Hand Creek, m Lefthand including all Feeder tributaries and Canal wetlands from Highway 36 to the confluence with St.

1. Vrain Creek.

COSPSV06 Tributaries to the Dry Creek . E. coli H St Vrain River COSPSV06 Tributaries to the all . Se L St Vrain River COSPSV13 All lakes and Lake D.O. . .

1. reservoirs tributary Thomas to Left Hand Creek from Hwy 36 to St. Vrain Creek.

COSPUS02 Tributaries to S. Salt Creek Temperatur . .

a Platte River, d/s of N. e source to Tarryall Fork, on Creek USFS Land COSPUS02 Tributaries to S. Twin Creek, Temperatur . .

a Platte River, on USFS e source to Tarryall Land Creek COSPUS02 Tributaries to S. S. Fork of Aquatic Life . .

a Platte River, S. Platte headwaters to below Tarryall Creek Antero Reservoir COSPUS02 Mosquito Creek all . Cd H b from South Mosquito Creek to the Middle Fork of the South Platte.

Code of Colorado Regulations 31 COSPUS02 South Mosquito No Name . Cd, Zn H c Creek from the Creek source to the confluence with Mosquito Creek and No Name Creek from the source to the confluence with Mosquito Creek COSPUS03 Tributaries to Trout Creek Aquatic Life sediment* H S.Platte River, and Tarryall Creek to tributaries N.Fk.S.Platte R on USFS property COSPUS03 Tributaries to Pine Creek . As H S.Platte River, Tarryall Creek to N.Fk.S.Platte R COSPUS03 Tributaries to Pine Creek, sediment . .

1. S.Platte River, on USFS Tarryall Creek to Land N. Fk. S. Platte River COSPUS03 Tributaries to Fourmile . Fe(trec), As, Hg H S.Platte River, Creek Tarryall Creek to N.Fk.S.Platte R COSPUS03 Tributaries to Sugar sediment . .
   1. S.Platte River, Creek, on Tarryall Creek to USFS Land N.Fk.S.Platte R COSPUS03 Tributaries to Hawkins Cd, Se . .

      S.Platte River, Gulch Tarryall Creek to N. Fk. S. Platte River COSPUS03 Tributaries to Horse D.O., Aquatic Life L S.Platte River, Creek Fe(trec) (provisional)

      Tarryall Creek to N. Fk. S. Platte River COSPUS03 Tributaries to West Creek As, Hg . .

      S.Platte River, Tarryall Creek to N. Fk. S. Platte River COSPUS03 Tributaries to Goose D.O. . .

      S.Platte River, Creek Tarryall Creek to N. Fk. S. Platte River Code of Colorado Regulations 32 COSPUS03 Tributaries to Trail and Fe(trec) . .

      S.Platte River, Wigwam Tarryall Creek to Creeks N. Fk. S. Platte River COSPUS04 N. Fk. S. Platte Hall Valley . pH H River & area to Tributaries, source Geneva Ck to S.Platte R COSPUS05 Gooseberry Gulch Unnamed . NH 3 M c and all tributaries Tributary to from source to Gooseberry confluence with Creek Elk Creek.

COSPUS06 Mainstem of the South Platte Aquatic Life . .

a South Platte River River from from the outlet of outlet of Cheesman Cheesman Reservoir to the Reservoir to inlet of Chatfield Fourmile Reservoir. Creek COSPUS07 Tributaries to the Willow Fe(Trec), . .

1. South Platte from Creek Se the North Fork of the South Platte to the outlet of Chatfield Reservoir.

COSPUS09 Mainstem of Bear Bear Creek D.O. . .

1. Creek, including all tributaries and wetlands from the source to the inlet of Perry Park Reservoir (Douglas County).

COSPUS10 Mainstems of East West Plum . Aquatic Life L a Plum Creek, West Creek (provisional)

1. 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.

Code of Colorado Regulations 33 COSPUS11a Tributaries to East all pH, . .

1. Plum Creek which Fe(Trec)
   1. are not on national forest lands.

COSPUS11a Tributaries to East Cook Creek . Aquatic Life L Plum Creek which (provisional)

1. are not on national forest lands.

COSPUS11b Tributaries to W. Spring Aquatic Life . .

1. Plum Creek, not Creek, Bear Use on USFS Land Creek COSPUS12 Garber and Jackson Pb . .
   1. Jackson Creeks Creek COSPUS14 S. Platte River all . As H COSPUS15 S. Platte River, all . E. coli H Burlington Ditch to Big Dry Creek COSPUS16 Sand Creek all . Se, E. coli L/H a COSPUS16 Tributaries to S. all . Se L c Platte River, Chatfield Reservoir to Big Dry Creek except specific listings COSPUS16 Tributaries to S. Westerly . E. coli H c Platte River, Creek, Dry Chatfield Creek Reservoir to Big Dry Creek except specific listings COSPUS16 Tributaries to S. Weir Gulch, E. coli . .

c Platte River, Sanderson Chatfield Gulch, Reservoir to Big Humble Dry Creek except Creek specific listings COSPUS16 Tributaries to S. Harvard, . E. coli (May-Oct) H c Platte River, Harvard Chatfield West, and Reservoir to Big Lakewood Dry Creek except Gulches specific listings COSPUS17 Washington Park Berkeley . Aquatic Life Use H a Lakes, City Park Lake, (Hg Fish Tissue)

1. Lake, Rocky Rocky Mountain Lake, Mountain Berkeley Lake Lake COSPUS17 Washington Park Rocky Cu, D.O. pH L a Lakes, City Park Mountain Lake, Rocky Lake Mountain Lake, Berkeley Lake Code of Colorado Regulations 34 COSPUS17 Washington Park Ferril Lake, . pH H a Lakes, City Park Smith Lake Lake, Rocky Mountain Lake, Berkeley Lake COSPUS17 Washington Park Smith Lake . NH 3 H a Lakes, City Park Lake, Rocky Mountain Lake, Berkeley Lake COSPUS17 Washington Park Grasmere Cu . .

a Lakes, City Park Lake Lake, Rocky Mountain Lake, Berkeley Lake COSPUS17 Washington Park Berkeley . D.O., As H a Lakes, City Park Lake Lake, Rocky Mountain Lake, Berkeley Lake COSPUS17 Washington Park Duck Lake . D.O., pH, NH 3 H a Lakes, City Park Lake, Rocky Mountain Lake, Berkeley Lake COSPUS17 Sloan’s Lake all Fe (Trec) D.O. .

b COSPUS23 All lakes and Barnum . D.O. L reservoirs in Lake watershed tributary to the South Platte from Chatfield to Big Dry Creek.

COSPUS23 Lakes and Vanderbilt . D.O. .

1. reservoirs in the Lake Upper South Platte watershed within the City and County of Denver.

COSPUS23 Lakes and Garfield Fe(trec) . .

1. reservoirs in the Lake, Upper South Harvey Platte watershed Lake, Aqua within the City and Golf Lake County of Denver.

COSPUS23 Lakes and Garfield . D.O. M reservoirs in the Lake, , Upper South Parkfield Platte watershed Lake, within the City and Huston County of Denver. Lake Code of Colorado Regulations 35 COSPUS23 Lakes and Aqua Golf . pH M reservoirs in the Lake, Upper South Huston Platte watershed Lake, within the City and Overland County of Denver. Lake, Parkfield Lake COSPUS23 Lakes and Huston E. coli . .

1. reservoirs in the Lake Upper South Platte watershed within the City and County of Denver.

COUC Upper Colorado . . . .

1. River Basin COUCBL02a Mainstem of the Blue all . Mn(WS) L River from the confluence with French Gulch to a point one half mile below Summit County Road 3.

COUCBL04a All direct tributaries to Gold Run Gulch Cd, Zn . . Dillon Reservoir and below Jessie Mine all tributaries and wetlands in the Blue River drainage above Dillon Reservoir.

COUCBL17 Mainstem of the Blue Blue River from Aquatic Life . . River from the outlet outlet of Dillon of Dillon Reservoir to Reservoir to N.

1. the confluence with Rock Creek the Colorado River. confluence COUCBL20 Mainstem of Elliott Spruce Creek Fe(Trec) . .
   1. Creek and Spruce Creek including all tributaries and wetlands from their sources to the confluence with the Blue River COUCEA05c Eagle River, Martin all . Cd H Creek to Gore Creek COUCEA06 Tributaries to Eagle Black Gore Creek, Aquatic Life Sediment H River, Belden to Lake adjacent to I-70 Creek, except specific segments COUCEA06 Tributaries to Eagle Mainstem of Lake . Aquatic Life L River, Belden to Lake Creek from below (provisional)
      1. Creek, except the confluence specific segments with East and West Lake Creek to the mouth Code of Colorado Regulations 36 COUCEA06 Tributaries to Eagle Beaver Creek Aquatic Life . . River, Belden to Lake from confluence Creek, except with Wayne Creek specific segments to Mouth COUCEA06 Tributaries to Eagle Red Sandstone Aquatic Life . . River, Belden to Lake Creek from USFS Creek, except Boundary to north specific segments side I-70 Frontage Road COUCEA06 Tributaries to Eagle Red Sandstone . Aquatic Life L River, Belden to Lake Creek from north (provisional)

         Creek, except side I-70 Frontage specific segments Road to confluence with Gore Creek COUCEA08 Mainstem of Gore all . Aquatic Life L Creek from the (provisional)

         confluence with Black Gore Creek to the confluence with the Eagle River.

COUCEA09a Mainstem of the From Berry Creek Temperature . . Eagle River from to confluence with Gore Creek to a point Ute Creek immediately below the confluence with Rube Creek.

COUCEA09a Mainstem of the From Ute Creek . Temperature H Eagle River from to confluence with Gore Creek to a point Rube Creek immediately below the confluence with Rube Creek.

COUCEA09a Mainstem of the Eagle River from Aquatic Life Sediment H Eagle River from confluence with Gore Creek to a point Berry Creek to immediately below confluence with the confluence with Squaw Creek Rube Creek.

COUCEA09a Mainstem of the Eagle River from Sediment . . Eagle River from Gore Creek to Gore Creek to a point confluence with immediately below Berry Creek and the confluence with from Squaw Rube Creek. Creek to confluence with Rube Creek COUCEA10a All tributaries to the Eby Creek Se . .

1. Eagle River from Lake Creek to the Colorado River.

COUCNP01 Tribs to the N Platte South Fork Big Cu, E.coli . . & Encampment Creek Rivers w/in Wilderness Areas Code of Colorado Regulations 37 COUCNP04a Tributaries to the Canadian River Fe(Dis), E. . . North Platte River coli except those tributaries in Segment 1, 4b, 6, 7a and 7b.

COUCNP04a All tributaries to N. Grizzly Creek, Aquatic Life . . Platte River except Little Grizzly Use segments 4b, 6, 7a Creek and 7b COUCNP04a All tributaries to N. Little Grizzly E.coli , . . Platte River except Creek Fe(Trec)

1. segments 4b, 6, 7a and 7b COUCNP04a All tributaries to N. Lake Creek pH, Fe(Trec) . . Platte River except segments 4b, 6, 7a and 7b COUCNP04a All tributaries to N. Big Creek Aquatic Life . . Platte River except Reservoir Use (Hg Fish segments 4b, 6, 7a Tissue)
   1. and 7b COUCNP04b Mainstem of the Illinois River . Fe (Trec) M 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.

COUCNP07b Government Creek, Spring Creek . D.O. M Spring Creek COUCNP09 All lakes and Lake John, North pH . .

1. reservoirs tributary to Delaney Lake the North Platte and Encampment Rivers COUCNP09 All lakes and Lake John . D.O. H reservoirs tributary to the North Platte and Encampment Rivers COUCRF03a Roaring Fork Capitol Creek Se . .
   1. including all tributaries and wetlands from Hunter Creek to the Colorado River except segments 3b through 10 Code of Colorado Regulations 38 COUCRF03a Roaring Fork West Sopris . Aquatic Life L including all Creek (provisional)
      1. tributaries and wetlands from Hunter Creek to the Colorado River COUCRF03a Roaring Fork Cattle Creek from . Aquatic Life L including all Bowers Gulch to (provisional)

         tributaries and mouth wetlands from Hunter Creek to the Colorado River COUCRF03a Roaring Fork Roaring Fork from . Aquatic Life L including all confluence with (provisional)

         tributaries and Hunter Creek to wetlands from Hunter below Brush Creek to the Creek confluence, Colorado River COUCRF03b Red Canyon Creek Landis Creek Fe(Trec) . .

         including all tributaries and wetlands from the source to the Roaring Fork except Landis Creek from source to Hopkins Ditch Diversion COUCRF04 Mainstem of Brush Mainstem Brush . Aquatic Life L Creek from the Creek (provisional)

         source to the confluence with the Roaring Fork River.

COUCRF07 All tributaries to the South Fork Frying . Aquatic Life L Fryingpan River Pan River from (provisional)

1. transbasin diversion to confluence with unnamed tributary (39.25128°N, - 106.59442°W)

COUCRF10 Thompson Creek Thompson Creek Fe(Trec) . .

1. including all tributaries and wetlands from the source to the Crystal River COUCUC02 Mainstem of the Willow Creek . Mn L Colorado River, Reservoir including all tributaries and wetlands within or flowing into Arapahoe National Recreation Area.

Code of Colorado Regulations 39 COUCUC03 Mainstem of the From 578 Road . Temperature, H Colorado River from Bridge to just Mn(WS)

1. Lake Granby to the above the Roaring Fork River. confluence with the Blue River COUCUC03 Mainstem of the From the outlet of Aquatic Life . . Colorado River from Windy Gap Lake Granby to the Reservoir to 578 Roaring Fork River. Road Bridge COUCUC06b Mainstem of all D.O. . .
   1. unnamed tributary from the headwaters to Willow Creek Reservoir Road COUCUC07a All tribs to the Alkali Slough . Fe (Trec), Se L 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.

COUCUC07a All tribs to the Muddy Creek and Temperature . . Colorado River, tribs 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.

COUCUC07b Muddy Creek from Muddy Creek Temperature . .

1. Wolford Mountain from Wolford Reservoir. Rock Mountain Creek, Deep Creek, Reservoir to Cow Sheephorn Creek Gulch Sweetwater Creek and Piney River.

COUCUC07b Muddy Creek from Muddy Creek . Temperature H Wolford Mountain from Cow Gulch Reservoir. Rock to the Colorado Creek, Deep Creek, River Sheephorn Creek Sweetwater Creek and Piney River.

Code of Colorado Regulations 40 COUCUC10a Mainstem of the Fraser River, . Aquatic Life L Fraser River from the Vasquez Creek (provisional)

1. source to a point immediately below the Rendezvous Bridge. All tributaries to the Fraser River, from the source to the Colorado River COUCUC10a Mainstem of the Ranch Creek . Temperature L 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.

COUCUC10c Mainstem of the all . Temperature L Fraser River from Hammond Ditch to the Colorado River.

COUCUC10c Mainstem of the From the Town of Cu . .

1. Fraser River, from Fraser to the the Hammond Ditch confluence with to the confluence the Colorado with the Colorado River.
   1. River COUCUC10c Mainstem of the From the Town of Pb . .
      1. Fraser River, from Tabernash to the the Hammond Ditch Town of Granby to the confluence with the Colorado River COUCUC12 Colorado River and Shadow Mountain . D.O. H tributaries, wetlands, Lake lakes and reservoirs within Arapahoe National Recreation Area COUCUC12 Lakes and Lake Granby . Aquatic Life H Reservoirs within Use (Hg Fish Arapahoe National Tissue)

         Recreation Area including Grand Lake, Shadow Mountain Lake and Lake Granby COUCYA02a Mainstem of the Yampa River Mn, Se . .

         Yampa River from below Stagecoach Wheeler Creek to Reservoir Oak Creek.

Code of Colorado Regulations 41 COUCYA02b All lakes and Elkhead . Aquatic Life H reservoirs tributary to Reservoir, Use (Hg Fish the Yampa River, Catamount Tissue)

1. Elkhead Creek, and the Little Snake River.

COUCYA02c Yampa River from all Temperature . .

1. Oak Creek to Elkhead Creek COUCYA03 All tributaries to Bushy Creek . Sediment L Yampa River except for specific listings, on USFS land COUCYA03 All tributaries to Walton Creek Mn . .
   1. Yampa River except for specific listings, on USFS land COUCYA03 All tributaries to Little Morrison Zn, Fe(dis) . . Yampa River except Creek for specific listings, on USFS land COUCYA04 Little White Snake all D.O. . .
      1. Creek, source to Yampa River COUCYA08 Elk River source to Elk River below . E.coli H Yampa River Morin Ditch COUCYA08 Elk River including Lost Dog Creek Hg . .

         tributaries and wetlands from the source to Yampa River COUCYA13b Foidel Creek and Fish Creek E.coli . .

         tributaries, Fish Creek, Middle Creek and tributaries COUCYA13d Dry Creek including Below Seneca . Se L all wetlands and sample location 8 tributaries from (WSD5)

         source to the Yampa River COUCYA13d Dry Creek including all . Fe(Trec) L all tributaries and (Snowmelt wetlands from source season)

         to the Yampa River COUCYA13d Dry Creek including Dry Creek below Pb, E. Coli . . all tributaries and Routt County wetlands from the Road 53 (Sec. 22, source to the Yampa T6N, R88W)

         River COUCYA13e Sage Creek, Grassy Sage Creek below . Se L Creek and tribs Routt County Road 51D Code of Colorado Regulations 42 COUCYA15 Mainstem of Elkhead Elkhead Creek . Aquatic Life L Creek and tributaries (provisional)

         Calf Creek and 80A Road on the Dry Fork of Elkhead Creek, to the confluence with the Yampa River.

COUCYA18 Little Snake River all Cu . .

1. including all tributaries and wetlands from forest boundary to Wyoming border

93.4 - 93.9 Reserved

93.10 STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE; MARCH, 2004

RULEMAKING 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 (303(d) List)

A. Introduction This regulation establishes Colorado’s List of Water-Quality-Limited Segments Requiring Total Maximum Daily Loads (“TMDLs” ). 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.

Once listed, the State is required to prioritize these water bodies or segments (rivers, streams, lakes reservoirs) based on the severity of pollution and other factors. It will then determine the causes of the water quality problem and allocate the responsibility for controlling the pollution. This analysis is called the TMDL Process, and results in the determination of: 1) the amount of a specific pollutant that a segment can receive without exceeding a water quality standard (the TMDL), and 2) the apportionment to the different contributing sources of the pollutant loading (the allocation). The TMDL must include a margin of safety, waste load allocation (for point sources) and a load allocation (for non-point sources and natural background). The TMDL must include upstream loads in the assessment and apportionment process.

B. List Development 1. Listing Methodology The “Section 303(d) Listing Methodology - 2004 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 on September 9, 2003. Code of Colorado Regulations 43 This Listing Methodology sets forth the criteria that generally were used to make decisions regarding which waters to include on the 2004 Section 303(d) List and the 2004 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.

2. Information Considered The Commission has considered all existing and readily available information in developing the 2004 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 2004 listing decisions. Such information will be considered in the next listing cycle.

C. 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 2004 Section 303(d) Listing Methodology. Segments/parameters where the Commission determined that an appropriate plan is in place to resolve the uncertainty as specified in section 93.4 have been denoted as “L*” . A Low priority may also be assigned to other segments as per section IV.

D. Discussion of Issues Raised in the Hearing During the course of the hearing, the status of approximately 30 segments was debated. The basis for the Commission’s decisions regarding the major issues for these segments is recorded below.

1. Selenium: Several parties questioned whether selenium, where the source is underlying native shale, should be considered a pollutant. The Commission found that selenium, like many other naturally occurring metals in Colorado is a pollutant and is classified as such on EPA’s list of priority toxic pollutants (62 FR 42160). If the source of impairment is natural, that is grounds for consideration of an ambient quality-based, site-specific standard as described in Regulation No. 31 at 31.7 1(b)(ii). However, the listing decisions must be made based upon a comparison of the current adopted standard and the ambient condition for the segment. Although parties to the rulemaking submitted testimony questioning the decision to list several specific segments for selenium, such as Lower Colorado River segment 3 and Lower Arkansas River segment 1a, the evidence provided was directed largely at questioning the appropriateness of the current selenium standards. The Commission has determined, based on the evidence submitted, that these segments are not in attainment of the current selenium standards.

2. Segments where there is no new data, but following the 2004 Listing Methodology resulted in a different conclusion than in 2002: The following segments had no new data included in the assessments since the 2002 listing cycle. However, clarification and changes in the 2004 Listing Methodology resulted in the segments moving from the Monitoring and Evaluation List to the 303(d) List. The modifications that resulted in the most changes had to do with more clearly specifying that segments with small datasets where the ambient condition exceeds the standard by more than 50 percent should be listed. The following segments were affected: Code of Colorado Regulations 44 Gunnison River Basin: Lower Gunnison segment 27 Uncompahgre segment 2 Lower Colorado River Basin: White River segment 9b 3. Segments with multiple tributaries: Issues were raised regarding what is the appropriate way to handle segments with multiple tributaries where there is evidence of impairment. The Commission found that since segments are generally treated as having consistent uses and characteristics, their impairment should be handled in a similar fashion. Unless either water quality data or other evidence has been presented that shows that the impairment is not present in the entire segment, the entire segment has been listed as impaired. “Other evidence” may include changes in geology within a segment or the confluence with a stream known to be impaired. Nevertheless, it is anticipated that before any TMDL is developed and implemented in “all tributary” segments, work will be performed to determine the causes and locations of the impairment, such that efforts and controls are not inappropriately directed towards individual tributaries that are not truly of concern, and the Section 303(d) List can be modified accordingly. Where other evidence shows that some portions are in exceedance and other portions are not, only the impaired portion needs to be listed. The following segments were listed based on this rationale:

Gunnison River Basin: Lower Gunnison segments 4a and 4b North Fork segments 5 and 6 Lower Colorado River Basin: Lower Colorado segment 4a E. Segment- Specific Issues 1. San Juan Basin, Dolores River below McPhee Reservoir: Despite a recent decline in the fish population in this reach, the Commission found that there was not adequate readily available evidence to conclude that there exists an impairment of the aquatic life use due to other than extraordinary events associated with the long-term drought that has existed in southwest Colorado for several years. In view of evolving operations of McPhee Reservoir and varying (and generally declining) hydrologic conditions, the Commission is not able at this time to identify an “expected condition” upon which to base a decision of impairment. Further, even if an impairment caused by other than the extraordinary events associated with the drought were found to exist, the Commission could not conclude based on this record that the decline was due to a “pollutant” as compared to “pollution.” Nevertheless, the Commission encourages cooperation by all interested parties in the implementation of habitat improvement measures that may serve to enhance the quality of the fishery in the reach. The Commission is prepared to revisit the concept of “expected condition” as it applies to this reach should that be warranted by changes in habitat condition. Certainly the achievement of goals set under the 1996 Operating Agreement for McPhee Reservoir may influence the nature of the expected condition. Finally, any evidence of impairment due to pollutants can be brought forth at the next listing hearing. Code of Colorado Regulations 45 2. South Platte Basin, Clear Creek, segments 14b and 15: Available data, with specific reference to biological information on fish species collected over time and visual observations of the physical condition of the stream bed, provide an indication of “use-impairment” for Clear Creek Segments 14b and 15 relative to aquatic life. Though organic sediment appears to be a significant contributor to the impairment, the exact interaction of potentially numerous causative factors need to be further explored. No single source or cause of the impairment has been identified to date. Coors Brewing Company has voluntarily come forward with a study plan for segments 14a, 14b and 15 as part of the “pilot study” approach outlined in the section 309 study report recently submitted to the State Legislature. This pilot study would assist in defining the expected condition for these segments in view of existing hydrological/habitat conditions and in fashioning the best approach to remedying the impairment. Should Coors decide to proceed with the pilot study, the Division will identify segments 14b and 15 as “low priority” and refrain from any further TMDL implementation measures until such time as the study results are known and an appropriate approach to rectifying the identified problems is crafted in cooperation with basin stakeholders.

3. Upper Colorado Basin, Blue River segments 6 and 8 (Camp Cr, Jones Gulch, Keystone Cr, and Mozart Creek): The four identified tributaries in these two segments were proposed by the Division to be listed as impaired relative to measured pH levels. The evidence submitted raised questions regarding the representativeness of the data showing a possible standards exceedance, particularly in the absence of data regarding seasonality of pH levels for multiple years. Therefore, the Commission determined that it is more appropriate to include these specific tributaries on the Monitoring and Evaluation List at this time. Keystone Resorts has stated that it will complete a Use Attainability Analysis for Camp Creek and Jones Gulch, and that it is willing to include Keystone Creek and Mozart Creek in this analysis. The Commission believes that it is appropriate to revisit the attainment status of these segments following completion of the UAA. Depending on the results of this analysis, the adoption of site-specific seasonal pH standards is one option that can be considered. Indeed, the Commission notes that the evidence submitted to it showed that nearby snowmaking actually mitigates pH levels in the snow.

4. Uncompahgre River, segment 6b (Red Mountain Creek): The Commission does not believe that an impairment of the aquatic life use of segment 6b relative to a realistic expected condition for this segment has been shown. The Commission found that the aquatic community in segment 6a is not the appropriate expected condition for this segment. The Commission endorses the Division’s proposal not to list at this time, while moving forward to investigate segment 6b and make a recommendation to the Commission regarding the attainable aquatic life use and appropriate numeric standards in the context of the next basin-wide standards and classification rulemaking proceedings. However, it is uncertain at this time whether any future remediation activities in this area will improve the aquatic life use of this segment. In the absence of documentation that the attainable expected condition for this segment is an aquatic life use that is better than the current condition of this segment, it would be inappropriate to identify this segment as impaired.

5. Bear Creek segment 1a: This segment was proposed by the Division and by Trout Unlimited to be included on the Section 303(d) List. The evidence submitted demonstrated adverse impacts to the aquatic life use in this segment during 2002, and documented that the use had started to recover in 2003, although full recovery had not yet occurred. The evidence also demonstrated that the unusual and extreme drought conditions in 2002 were the determinative cause of the adverse impacts to aquatic life. Although there was evidence submitted indicating that ammonia concentrations or elevated temperatures may have adversely affected the aquatic life, the evidence demonstrated that these potentially harmful conditions would not have been present except for the drought. The Commission has concluded that this segment should be included on the Monitoring and Evaluation List for potential aquatic life, ammonia and temperature impairments, and that its status should be reconsidered in future updates of Regulations No. 93 and No. 94. Any evidence of impairment due to pollutants can be brought forth at the next listing hearing.

Code of Colorado Regulations 46 6. Lower Colorado segment 13b: This is an “all tributaries” segment that was proposed by the Division to be listed in its entirety for selenium. All of the ambient water quality data available in the record for this hearing was from tributaries on the north side of the Colorado River. In addition, there was testimony regarding significant differences in the geology on the north and south sides of the Colorado River in this area. Therefore, the Commission determined that it is appropriate that only the tributaries on the north side of this segment should be listed as impaired for selenium.

7. West Fork of Clear Creek, segment 5: The Commission found that the acute zinc standard in the West Fork of Clear Creek was exceeded more than once in three years. Because the chronic zinc standard is in attainment, and because Climax presented credible biological evidence that the aquatic life use classification is supported, the Commission determined that listing for acute zinc is not warranted in this instance. This segment is included on the Section 303(d) List as impaired for copper.

8. Middle South Platte segment 1: The Division proposed that the portion of this segment from Big Dry Creek to Highway 60 be included on the Section 303(d) List as impaired for dissolved oxygen during the months of August and September. The evidence submitted offered conflicting interpretations of what the available data for this segment show regarding attainment. Because this segment appears to be in compliance with dissolved oxygen standards based on the established convention of looking at the 15th percentile of the available data for the entire segment, the Commission determined that it is more appropriate at this time to include this segment on the Monitoring and Evaluation List for further assessment of dissolved oxygen conditions. The Commission also believes that future clarification of the appropriate methodology for assessing attainment of dissolved oxygen standards, e.g. within specific months of the year, would be helpful.

F. Plans to Resolve Uncertainty Three parties presented plans to resolve uncertainty for segments that have temporary modifications based on uncertainty [see Regulation No. 31.7(3)(a)(iii)]. These segments will not be subject to the development of a TMDL as long as there is a plan in place that addresses the following:

(1) There is an appropriate plan in place to remove the uncertainty;

(2) The plan includes an implementation schedule that will resolve the uncertainty in a time frame consistent with Colorado’s timeline for the development of TMDLs; and (3) The plan is being implemented in accordance with its terms. The Commission found that the following segments have adequate plans. It is the Commission’s intent to revisit these plans at the next listing cycle to determine if they continue to meet the Commission’s intent.

1. Fountain Creek segment 6 (Monument Creek from the National Forest boundary to Fountain Creek): The selenium water quality standard for Fountain Creek segment 6 has a temporary modification for uncertainty pursuant to section 31.7(3)(a)(iii) of the Basic Standards. The City of Colorado Springs submitted an appropriate plan to remove the uncertainty 2. Lower Arkansas segment 1a (Arkansas River from Fountain Creek to the Colorado Canal): The selenium water quality standard for Lower Arkansas segment 1a has a temporary modification for uncertainty pursuant to section 31.7(3)(a)(iii) of the Basic Standards. The City of Pueblo submitted an appropriate plan to remove the uncertainty Code of Colorado Regulations 47 3. Upper Yampa segment 13d (Dry Creek): In the 2003 Upper Colorado River rulemaking hearing, the Commission adopted a temporary modification (based on uncertainty) of 60 ug/L for selenium in Dry Creek. This temporary modification was based on five WQCD samples collected in Dry Creek in 2001 and 2002 near its confluence with the Yampa River. The Commission approved Seneca Coal Company’s plan to monitor Dry Creek with the objective of determining the source or sources of selenium loading, where the loading is isolated in the lower portion of Dry Creek and to determine whether the loading is due to natural or irreversible man-induced sources. BASIS AND PURPOSE (Monitoring and Evaluation List)

A. Introduction This regulation establishes Colorado’s Monitoring and Evaluation List. This list was prepared as part of the effort to identify water bodies for which technology-based effluent limitations and other required controls are not stringent enough to implement water quality standards (those impaired waters requiring TMDLs). Regulation No. 93 is the list of impaired waters which require TMDLs. This regulation is the Monitoring and Evaluation List (“M&E List” ) that identifies water bodies where there is reason to suspect water quality problems, but there is also uncertainty regarding one or more listing factors, such as the representative nature of the available 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 included on the M&E List.

B. List Development The statement of basis and purpose for Regulation No. 93 contains a description of how the lists were developed.

C. Prioritization and Scheduling The Division has committed to establishing a plan for monitoring and evaluating these water bodies 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.

D. Segment-Specific Issues 1. Blue River segment 3: The Commission has included Gold Run Gulch below Jessie Mine (for cadmium and zinc) and the South Branch Swan River below Royal Tiger Mine (for zinc) on the Monitoring and Evaluation List. The Royal Tiger Mine and the Jessie Mine are both part of a CERCLA remediation effort, for which remedial project design is currently out to bid. Therefore, the Commission understands that the conditions in this area affecting water quality will be changing and that it is currently uncertain what uses or water quality can be supported in these waters in the future. The Commission does not intend by including these waters on the Monitoring and Evaluation List to conclude that any actions other than those CERCLA-related activities already underway are necessary or appropriate at this site. The status of those efforts will be reviewed during the next update of this list.

2. Segments proposed for the Section 303(d) List: In several specific instances, the Commission made a determination in this rulemaking hearing that segments proposed by the Division or others for inclusion on the Section 303(d) List should instead be included on the Monitoring and Evaluation List. This applies in particular to Bear Creek segment 1a and Middle South Platte segment 1 in the South Platte Basin and to four named tributaries in Blue River segments 6 and 8 in the Upper Colorado River Basin. In each of these instances, the rationale for the Commission’s decision to included these waters on the Monitoring and Evaluation List is set forth in the Statement of Basis and Purpose adopted for Regulation No. 93 as a result of this rulemaking. Code of Colorado Regulations 48

93.11 STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE; FEBRUARY,

2006 RULEMAKING, EFFECTIVE DATE OF APRIL 30, 2006 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 (303(d) List)

A. 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 promulgated in 2004. 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.

B. List Development 1. Listing Methodology The “Section 303(d) Listing Methodology - 2006 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 on May 9, 2005. This Listing Methodology sets forth the criteria that generally were used to make decisions regarding which waters to include on the 2006 Section 303(d) List and the 2006 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.

2. Information Considered The Commission has considered all existing and readily available information in developing the 2006 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 2006 listing decisions. If submitted, such information will be considered in the next listing cycle.

C. 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 2006 Section 303(d) Listing Methodology. Code of Colorado Regulations 49 D. Temporary Modifications and Plans to Eliminate Uncertainty Consistent with the recent changes to the Basic Standards and Methodologies for Surface Water (Regulation No. 31) and the Discharge Permit Regulations (Regulation No. 61), the Commission deleted subsection 93.4 “Plans to Eliminate Uncertainty.” The Statement of Basis for the June 2005 rulemaking hearing for Regulation No. 31 states:

The Commission recognizes that portions of the temporary modification provisions adopted in this rulemaking may be inconsistent with current provisions in Regulation No. 93. The Commission intends that the provisions adopted in this rulemaking will govern until appropriate revisions will be adopted in the Regulation No. 93 in the next rulemaking hearing reviewing that regulation. In 2004, this provision was added to Regulation No. 93 to identify those waterbodies where work independent of the TMDL process was proceeding to identify the appropriate underlying standards. In these cases, TMDLs and permit limits were not to be based on the underlying standards until the uncertainty was resolved. The intent was that dischargers should not be forced to comply with underlying standards where there is ongoing work being done to resolve acknowledged uncertainty regarding the appropriateness of those underlying standards.

Dischargers are now protected from complying with underlying standards before the uncertainty is resolved by recent changes in the Basic Standards and the Permit Regulations. Now, for discharges to waters where a temporary modification has been adopted, a permit may contain compliance schedules that recognize this ongoing work and may extend beyond the end of the permit term. The Commission believes it appropriate for dischargers to focus their available resources on addressing uncertainty with respect to appropriate water quality standards, rather than on complying with standards that may change in a short time.

Consistent with this new approach to temporary modifications, the Commission intends that a more thorough consideration will be given to the causes and sources of non-attainment before temporary modifications are proposed. In cases where the appropriate way to address non-attainment of underlying standards is through the TMDL program, not through adoption of temporary modifications, the Commission may assign a higher TMDL priority to such waters.

E. Segment- Specific Issues Fountain Creek segment 2a: The Division had proposed inclusion of this segment due to non-attainment of the assigned E. coli standard. The Division noted that its proposal erroneously identified the listing as a “low” priority. The Section 303(d) Listing Methodology, 2006 Listing Cycle indicates that TMDLs for waters in non-support of Recreation 1a use classifications be designated as “high” priority. The Commission has therefore adopted a “high” priority designation for this segment. Fountain Creek segment 2b: This segment is the lowermost of three that comprise the mainstem of Fountain Creek. Both of the upper two segments are included on the List of Impaired Waters for E. coli. The Sierra Club had proposed that this lowermost segment should also be listed for E. coli. The Commission has decided that the Division’s analysis of the available data is consistent with the procedures contained in the Section 303(d) Listing Methodology, 2006 Listing Cycle and that the results of that analysis do not support inclusion of this segment on the Section 303(d) List of Water-Quality- Limited Segments Requiring TMDLs.

North Fork Gunnison River segment 6: The Division had proposed that this “all tributary” segment be listed in its entirety for non-attainment of the aquatic life use-based chronic selenium standard. The Colorado River Water Conservation District provided evidence that the standard is, in fact, attained at several locations within this segment. It is therefore appropriate that only that portion of the segment for which non-attainment has been documented be included on the list. The Commission has identified the affected portion of the segment as “Cottonwood Creek” and has revised the proposal accordingly. Code of Colorado Regulations 50 Uncompahgre River segment 6b (Red Mountain Creek): The Commission had in a February 2004 Rulemaking Hearing determined that there is not adequate data to support a finding of impaired Aquatic Life Use relative to the expected condition. Information offered in the 2006 hearing further reinforces this conclusion by demonstrating that the Commission’s classification assumes an extremely limited aquatic life use in this segment. In a rulemaking hearing scheduled for June 12, 2006, the Commission will consider a proposal to delete the aquatic life use classification for this segment. The Commission has therefore opted not to include Red Mountain Creek on the 2006 Section 303(d) List of Water-Quality- Limited Segments Requiring TMDLs.

Lower Gunnison segment 2: The Division proposed that this segment be listed for selenium and temperature, with a "high" priority for each. In view of evidence that it may be appropriate to reconsider the cold water aquatic life classification of this segment prior to initiating a TMDL, the Commission chose to change the priority for the temperature listing to "low". Lower Colorado River segment 3: The Division had initially proposed listing of this segment for ammonia. During discussions with the City of Grand Junction it was noted that during the course of the Division’s assessment an error had been made relative to the dataset utilized. The Division subsequently modified its proposal to withdraw this segment from its proposal. The Commission has not included the segment on the 2006 Section 303(d) List of Water-Quality-Limited Segments Requiring TMDLs. Lower Colorado River segment 13a (Salt Creek): Salt Creek was proposed by the Division to be listed for sediment based upon a study of this and other tributary segments performed in conjunction with the BLM and Chadwick and Associates. Mesa County objected to the inclusion of Salt Creek on the Section 303(d) List of Water-Quality-Limited Segments Requiring TMDLs, arguing that the assessment protocols used were inconsistent with Commission Policy 98-1, the Implementation Guidance for Determining Sediment Deposition Impacts to Aquatic Life in Streams and Rivers. The assessment performed utilized the same approach embodied in the Sediment Guidance with respect to comparison of the affected reach to an expected condition. The validity of this comparative, expected condition analysis is not dependent on this being a high gradient, cobble bottom stream. The Commission has determined that the assessment adequately demonstrated non-attainment of the narrative sediment standard and consequent impairment of Salt Creek.

Bear Creek segment 1a: The Division proposed that this segment be retained on the Monitoring and Evaluation list for non-attainment of the assigned aquatic life use classification and for temperature. The evidence submitted demonstrated adverse impacts to trout populations at two stations (Bear Creek cabins and O’Fallon Park) situated in the upper reach of this segment since 2002 and documented that the use continued to recover well into 2004, although full recovery had not yet occurred. This evidence is consistent with the Commission’s conclusion in 2004 that the demonstrative cause of adverse impacts to aquatic life was the extreme drought in 2002. The 2006 Listing Methodology states that “Data collected during or immediately after temporary events influencing the waterbody that are not representative of normal conditions shall typically be discounted in making the listing decision.” Several parties argued that water quality conditions might have adversely affected the aquatic life. However, there was no evidence submitted demonstrating exceedance of the Mean Average Weekly Temperature criterion during 2004 or 2005, or demonstrating that impairment was otherwise caused by pollutants. The Commission has decided that the Division’s interpretation of the available data is consistent with the procedures contained in the Section 303(d) Listing Methodology, 2006 Listing Cycle and has determined that this segment should be retained on the Monitoring and Evaluation List for aquatic life impairments and temperature, and that its status should be reconsidered in future updates of Regulations No. 93 and No. 94. Code of Colorado Regulations 51 The fact that impacts to Bear Creek aquatic life continue to appear to be related to the 2002 extreme drought is an adequate and appropriate basis for including this segment on the Monitoring and Evaluation List, rather than the Section 303(d) List. However, the Commission also notes that, even if continuing impacts did not appear to be tied to the drought, where there is no evidence that a numerical standard has been exceeded, the Commission’s practice has been to place waters on the Monitoring and Evaluation List if there is not evidence that a use impairment has been caused by a pollutant. The 2006 Listing Methodology states “Water bodies that are impaired but it is unclear whether the cause of impairment is attributable to pollutants as opposed to pollution will be placed on the M&E List.” EPA’s guidance for such circumstances differs. EPA’s guidance says that where there is an impairment but there has not been a demonstration that the impact is not caused by a pollutant, the water segment should be included on the Section 303(d) List. Because this provision appears in EPA guidance only, and the Commission is aware of no specific provisions of the Clean Water Act or EPA regulations that would dictate this result, the Commission believes that it has policy discretion to use different approach – i.e., to refrain from listing unless a pollutant has been identified as the cause of the use impairment. Clear Creek segment 13b (North Fork Clear Creek): The Division had proposed this segment be retained on the Section 303(d) List of Water-Quality-Limited Segments Requiring TMDLs for several parameters and for non-attainment of the assigned aquatic life use classification. The Commission has adopted this proposal, but notes that the segment attains the assigned numeric copper standard. The listing therefore does not include copper. Further, the Commission notes that the Division had proposed a “high” priority for completion of TMDLs for this segment, due to the fact that the North Fork of Clear Creek was included on the 1998 List of Impaired Waters and is therefore subject to provisions of the 1999 Settlement Agreement addressing TMDL development by the Division. The Commission has determined that a “medium” priority will be assigned for TMDL development, while recognizing that the Division remains obligated to completion of TMDLs for this segment by June 30, 2008. If the underlying standards are revised in the 2009 South Platte River basin rulemaking, TMDLs and/or Wasteload Allocations based on the superceded standards should be revisited.

Cache la Poudre segment 14 (Horsetooth Reservoir): The Division proposed inclusion of Horsetooth Reservoir on the Section 303(d) List of Water-Quality-Limited Segments Requiring TMDLs due to non- attainment of the dissolved oxygen standard. Data for a ten-year period of record was found to be representative of conditions in the Reservoir. The Commission determined that in this instance it is appropriate to consider data for more than the most recent five years, in view of evidence that the most recent five years include a potentially unrepresentative period of reservoir drawdown. While the available data do not include samples spaced throughout a 24-hour period, the data are typical of that usually available for lakes and reservoirs. If diel variation were expected, it is likely that any such data would demonstrate a slight depression of dissolved oxygen concentration in the epilimnion during non-daylight hours. However, the area of non-attainment of dissolved oxygen in Horsetooth Reservoir is in the metalimnion, or middle layer of the reservoir. Testimony from Division staff indicated that it is unlikely that diel variation in dissolved oxygen levels would be expected in the metalimnion, since this deeper layer is unlikely to be affected by photosynthesis that occurs in the epiliminion. The Commission interprets the reference in the Listing Methodology to lake and reservoir samples representative of diel variation to apply only in those factual circumstances (e.g. dissolved oxygen in the epilimnion) where such variation would be expected.

The assessments and recommendations by the Division regarding Horsetooth Reservoir were consistent with the Section 303(d) Listing Methodology, 2006 Listing Cycle. However, the Commission notes that this hearing identified a need to provide further clarifications regarding appropriate procedures for assessing compliance with dissolved oxygen standards, particularly for lakes and reservoirs. The Commission encourages the Division to pursue such clarifications in preparation of the 2008 Listing Methodology, including, e.g., addressing variations in attainment status from year-to-year and further clarification of what constitutes representative data.

Code of Colorado Regulations 52 Evidence regarding the status of aquatic life in Horsetooth Reservoir does not override the fact that the data demonstrate a long term standards exceedance. The Commission’s practice has been to list waterbodies on the Section 303(d) List whenever representative data demonstrate non-attainment of a numerical standard, including dissolved oxygen. For other waters listed for non-attainment of dissolved oxygen, the Commission has not required evidence of the cause of the non-attainment. Although the provisions of the 2006 Listing Methodology arguably contain potentially conflicting language on this point, the Commission’s practice has not been to apply the provision regarding “water bodies that are impaired but it is unclear whether the cause of impairment is attributable to pollutants” to waters with dissolved oxygen impairments. Moreover, although the Commission was willing to consider listing Horsetooth Reservoir on the M&E List if the cause of the dissolved oxygen impairment was recent reservoir draw downs (i.e., reservoir operations), the evidence did not support this conclusion. Middle South Platte River segment 03a (Horse Creek Reservoir): The Division proposed that Horse Creek Reservoir be included on the Section 303(d) List of Water-Quality-Limited Segments Requiring TMDLs due to non-attainment of the assigned pH standard. The recommendation was based upon a representative dataset including four years of water quality monitoring results. The Commission has determined that inclusion of the Reservoir on the Section 303(d) List of Water-Quality-Limited Segments Requiring TMDLs for pH is appropriate and consistent with the Section 303(d) Listing Methodology, 2006 Listing Cycle. Dissolved oxygen data for the same four-year period demonstrate attainment of the dissolved oxygen standard. Although EPA questioned the Division’s current practice of averaging dissolved oxygen data within the sampling profile or profiles for a single sampling event, the Commission has determined that this practice is acceptable and appropriate, and consistent with the 2006 Listing Methodology. EPA’s proposal that Horse Creek Reservoir be listed for dissolved oxygen is based upon analytical procedures that are inconsistent with the Division’s current assessment practice. The Commission has determined that the Reservoir is not impaired with respect to the dissolved oxygen standard.

Upper Colorado River segment 07b (Muddy Creek): The Division had proposed the listing of Muddy Creek for non-attainment of the assigned temperature standard. The Colorado River Water Conservation District objected to the Division’s proposal and has provided evidence suggesting that the USGS sampling station (data from which formed the basis for the Division’s proposal) is situated such that any temperature data generated is likely not representative. The Commission has therefore included the segment on the 2006 Monitoring and Evaluation List to allow further examination of temperature data from this station.

Upper Yampa River segment 07b: This segment comprises a portion of the Yampa River mainstem. The Division had proposed that this segment be listed for temperature, again based upon USGS monitoring data. The Colorado River Water Conservation District provided evidence concerning the location of the USGS sampling station below the Steamboat Springs hot springs discharge. Again parties have agreed that such data is likely not representative of instream conditions. The Commission has placed the segment on the 2006 Monitoring and Evaluation List.

Upper Yampa River segment 20 (First Creek, Elkhead Creek): These waters are classified for Recreation Use 1a, and are assigned a numeric E coli standard of 126 org./100 mL. Ambient E. coli levels exceed the assigned numeric standard. The U. S. Forest Service has raised concerns regarding the current assigned Recreation Use and the associated numeric standards. The Commission has included the segment on the 2006 Section 303(d) List of Water-Quality-Limited Segments Requiring TMDLs based upon the current classification and standards. However, it is the intent of the Commission that these issues be examined in the context of the 2008 Upper Colorado surface water standards rulemaking prior to the initiation of the TMDL development process.

BASIS AND PURPOSE (Monitoring and Evaluation List)

A. Introduction Code of Colorado Regulations 53 This regulation updates Colorado’s Monitoring and Evaluation List to reflect additional water quality information available since the Regulation was promulgated in 2004.

B. List Development The statement of basis and purpose for Regulation No. 93 contains a description of how the lists were developed.

C. Prioritization and Scheduling The Division remains committed to establishing a plan for monitoring and evaluating these water bodies 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.

D. Segment-Specific Issues In a number of instances, the Commission chose in this hearing to include on the Monitoring and Evaluation List waters that were initially proposed by the Division, or recommended by other rulemaking participants, for inclusion on the Section 303(d) List, Regulation #93. These waters include Bear Creek segment 1a, Upper Colorado River segment 07b (Muddy Creek), and Upper Yampa River segment 07b. In each instance, the Commission’s rationale for these decisions is set forth in the statement of basis and purpose for Regulation #93.

1. PARTIES TO THE RULEMAKING

1. The City of Grand Junction 2. The Colorado Division of Wildlife 3. Evergreen Trout Unlimited and Colorado Trout Unlimited 4. The City of Colorado Springs 5. The City of Black Hawk 6. The Colorado River Water Conservation District 7. Friends of Bear Creek 8. Big Thompson Watershed Forum 9. The Bear Creek Watershed Association 10. The Northern Colorado Water Conservancy District 11. U.S. Environmental Protection Agency, Region 8 12. Evergreen Metropolitan District and West Jefferson County Metropolitan District 13. USDA Forest Service, Medicine Bow-Routt National Forests 14. Colorado Rock Products Association 15. City and County of Broomfield Code of Colorado Regulations 54 16. Climax Molybdenum Company 17. The Metro Wastewater Reclamation District 18. Mount Carbon Metropolitan District

93.12 STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE; FEBRUARY,

2008 RULEMAKING, EFFECTIVE DATE OF APRIL 30, 2008 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 (303(d) List)

A. 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 promulgated in 2006. 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.

B. List Development 1. Listing Methodology The “Section 303(d) Listing Methodology - 2008 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 on May 15, 2007. This Listing Methodology sets forth the criteria that generally were used to make decisions regarding which waters to include on the 2008 Section 303(d) List and the 2008 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.

2. Information Considered The Commission has considered all existing and readily available information in developing the 2008 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 2008 listing decisions. Such information will be considered in the next listing cycle. Code of Colorado Regulations 55 C. 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 2008 Section 303(d) Listing Methodology.

D. Fish Consumption Advisory Listings Consistent with the 2008 Section 303(d) Listing Methodology, the Division proposed to include 12 segments on the 2008 303(d) List for non-attainment of the aquatic life use due to fish consumption advisories for mercury. The 2008 Section 303(d) Listing Methodology, states: Fish Consumption Advisories are issued by the Colorado Department of Public Health and Environment (“CDPHE” ) in instances where analysis of fish tissue samples provides documentation of a public health risk. Issuance of a FCA by CDPHE indicates impairment of an Aquatic Life Use classification for any waters so classified.

The 2006 303(d) List included three of these reservoirs for impairment due to mercury: one in the Rio Grande basin: Sanchez Reservoir (Rio Grande, segment 30), and two in the San Juan basin: McPhee Reservoir (Dolores, segment 4) and Narraguinnep Reservoir (La Plata, segment 11). These listing were changed by the Commission to specify that the listing was based on non-attainment of the aquatic life. This is consistent with the 2008 Listing Methodology and avoids confusion that there is non-attainment of the mercury standard in the water column.

The Commission has included 12 segments on the 2008 303(d) List for non-attainment of the aquatic life use due to mercury fish consumption advisories for 13 lakes or reservoirs. The Commission also included 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.

E. Discussion of Issues Raised in the Hearing Dissolved Oxygen Standard in Lakes and Reservoirs: The issue of an appropriate D.O. standard in lakes and reservoirs was raised in this hearing by two parties, Northern and the River District. The River District focused its attention to high elevation lakes and reservoirs while Northern discussed the concept of representative data and assessment methods as outlined in the 2008 Listing Methodology. The Division agreed that work is needed to examine the D.O. standard for lakes and reservoirs and that additional refinement of the Listing Methodology is appropriate including consideration of whether and how refugia should be addressed. This standard is scheduled for review in preparation for the 2010 Basic Standards and Methodology, Regulation No. 31, RMH in June 2010. The Commission directs the Division to work with parties in 2008 and 2009 on any changes that are deemed appropriate for the 2010 Listing Methodology. The Commission made listing decisions based on the available data using the adopted standards and the 2008 Listing Methodology. Site-specific decisions made by the Commission are discussed below.

F. Segment- Specific Issues Fountain Creek segment 6, Monument Creek: Mainstem of Monument Creek from the boundary of National Forest Lands to the confluence with Fountain Creek: The Division had proposed retaining the portion of Monument Creek below Mesa Road on the 2008 303(d) List because selenium concentrations in that portion exceed the water quality standard for Fountain Creek Segment 6. The Commission has determined that it is appropriate at this time to include this portion of Monument Creek on the 2008 303(d) List. However, because there is an appropriate plan in place to address the segment as a whole, the Commission directs the Division and Colorado Springs Utilities to revisit this plan to determine the causes and potential reversal of elevated Se concentrations and the appropriate long-term underlying standard for this section of COARFO06.

Code of Colorado Regulations 56 Lower Colorado segment 2, Colorado River (COLCLC02): Mainstem of the Colorado River from Parachute Creek to the Gunnison River. The Division originally proposed listing this segment based on non-attainment of the selenium standard. The Division based its proposal on data from multiple sampling locations. The River District questioned whether some of the sample locations, including the Humphrey backwater location and others, were in the segment. The Division reviewed the sampling locations and determined that some of the sampling locations used in the original proposal were outside the segment. The segment was reassessed and still showed impairment. The parties disagree whether Humphrey Backwater is located within the segment but agreed that it demonstrated exceedences of the selenium standard. The Commission ultimately decided to list the Humphrey Backwater portion of the Colorado River segment based on those data, rather than listing the entire segment. White River segment 13b: Shell Frontier Oil and Gas Inc. provided additional analytical results for a number of locations within the Yellow Creek drainage. Re-assessment of several waters which had been proposed for inclusion on the Monitoring and Evaluation List indicated that Corral Creek, Box Elder Gulch, Stake Springs and Duck Creek, are all in attainment of the assigned standard for total recoverable iron. This additional data, however, also demonstrated that the lower portion of Corral Creek and Duck Creek are in non-attainment of the Aquatic Life Use-based chronic selenium standard. The Commission has added these waters to the 303(d) List for selenium.

Upper Colorado segment 5, Wolford Mountain Reservoir (COUCUC05): The River District opposed the Division’s proposal to move Wolford Reservoir from the 2006 M&E List to the 2008 303(d) List when no additional data has been collected. In addition, the River District expressed their concerns with the current D.O. standard and Listing Methodology especially as it is applied to high alpine lakes and reservoirs. The Commission moved Wolford Reservoir from the M&E List to the 303(d) List based on the current standards and listing methods. The Commission has encouraged the Division, the River District and other parties to continue to work towards an improved D.O. standard for the 2010 Basic Standards Rulemaking Hearing. The Commission adopted a low priority for this listing, since it is appropriate for the D.O. standard and listing methodology issues to be addressed before substantial resources are expended on development of a TMDL.

Uncompahgre segment 14, Sweitzer Lake (COGUUN14): The Division proposed listing for Sweitzer Lake due to exceedances of the D.O. standard in the mixed layer. The River District pointed out that there was no thermal stratification and adequate refugia present and therefore the segment should not be listed. They also indicated that there is evidence of chemical stratification. The Commission listed Sweitzer Lake, segment COGUUN14, on the 303(d) List due to exceedances in the mixed layer as defined in the Listing Methodology.

Upper Yampa segment 13d, Dry Creek (COUCYA13d): The Division proposed listing the Hubberson Gulch tributary of this segment due to non-attainment of the total recoverable iron standard. Seneca Coal Company (Seneca) provided evidence that the tributary is in attainment of the standard. The Commission did not list the segment for total recoverable iron on the 303(d) List. Upper Yampa segment 13e, Sage and Grassy Creeks (COUCYA13e): The Division proposed listing this segment due to non-attainment of the total recoverable iron and dissolved selenium standards. Seneca provided evidence that the total recoverable iron standard is attained within the segment. The Commission did not include the segment on the 303(d) List for total recoverable iron. Seneca also provided evidence that the selenium standard is attained in the upper portions of the two creeks in the segment. The Commission did include the lower portion of the creeks (Sage Creek below Routt County Road 51D and Grassy Creek below Routt County Road 27A), on the 303(d) List for dissolved selenium. BASIS AND PURPOSE (Monitoring and Evaluation List)

A. Introduction This regulation updates Colorado’s Monitoring and Evaluation List to reflect additional water quality information available since the Regulation was promulgated in 2006. Code of Colorado Regulations 57 B. List Development The statement of basis and purpose for Regulation No. 93 contains a description of how the lists were developed.

C. Prioritization and Scheduling The Division remains committed to establishing a plan for monitoring and evaluating these water bodies 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.

D. Segment Specific Issues 1. Lower Dolores segment 3 (COGULD03): The Commission approved resegmentation of Lower Dolores segment 3 at the Regulation 35 Rulemaking Hearing in June 2006. The resegmentation was based on the Division’s investigation identifying Salt Creek draining the Sinbad Valley. The Sinbad Valley is identified by the Colorado Geological Survey as a graben or a collapse feature that formed in response to salt migration and dissolution beneath the area. Based on this information the selenium and zinc standards for the new Salt Creek segment were set at ambient conditions. The Division proposed to delete this from the M&E List based on attainment of the new ambient standards. The Commission removed this segment from the M&E List.

2. Bear Creek segment 1a (COSPBE01a): This segment was removed from the M&E List based on assessment of annual fish surveys, water quality parameters and temperature data. It is noted that Bear Creek has seen significant improvement but still requires continued cooperative efforts by the Division, DOW, the Bear Creek Watershed Authority, Trout Unlimited and others to prevent future impairment or re-listing.

3. Blue River segment 3 (COUCBL03): The Commission has included Gold Run Gulch below Jessie Mine (for cadmium and zinc) and the South Branch Swan River below Royal Tiger Mine (for zinc) on the 2006 Monitoring and Evaluation List. The Royal Tiger Mine and the Jessie Mine are both part of a CERCLA remediation effort completed in 2007. Remediation results with respect to water quality are not yet available. In the past the Commission did not intend by including these waters on the Monitoring and Evaluation List to conclude that any actions other than those completed CERCLA-related activities are necessary or appropriate at this site. The status of those efforts will be reviewed during the next update of this list.

4. White River segment 16 (COLCWH16): The Commission has included Ryan Gulch on the Monitoring and Evaluation List for E. coli. Shell had argued that Ryan Gulch should not be included on the Monitoring and Evaluation List for E. coli due to the lack of more than a single sample and because “the segment does not appear to support classification as recreation class 2.” The Commission notes that placement of the water on the Monitoring and Evaluation List does not indicate a finding that Ryan Gulch is in non-attainment with the assigned Recreational Use, only that more data is needed to accurately assess the attainment status. Further, the Commission would note that alternate Recreation Use designations have more stringent E. coli standards then that assigned with the current Recreation Use designation.

5. Upper Yampa segment 13d, Dry Creek (COUCYA13d): The Division proposed listing this segment due to exceedances of the lead standard. Seneca provided evidence that the lead standard is attained within the upper portion of this segment. The Commission included the lower portions of the segment (below Routt County Road 53 (Sec. 22, T6N, R88W)), on the 2008 M&E List for dissolved lead.

Code of Colorado Regulations 58 6. Uncompahgre segment 3b, Ridgeway Reservoir (COGUUN03b): Listing methods for temperature in lakes were changed in the Section 303(d) Listing Methodology – 2008 Listing Cycle to reflect changes in the temperature standards in Regulation No. 31. In the Listing Methodology (p. 25) it states: “If the refuge is not adequate because of low dissolved oxygen, the lake or reservoir may be listed as impaired for dissolved oxygen rather than for temperature.” The Division proposed a few segments for the M&E List that are listed for dissolved oxygen due to exceedances of temperature in the epilimnion where there was not adequate refugia in the lower levels of the lake or reservoir. Ridgeway Reservoir was one of those segments. The data showed that the temperature standard was exceeded in the epilimnion on 7/21/05. An adequate refuge from high temperatures in the epilimnion was not present on that day due to inadequate dissolved oxygen in the lower portion of the lake. Due to confusion that this type of listing caused, the parameter notation in Regulation No. 94 was changed to indicate that the D.O. listing was due to exceedances of the temperature standard. The Commission added Ridgeway Reservoir; segment COGUUN03b, to the M&E List for “D.O. (temperature)” .

7. Fountain Creek segment 2a (COARFO02a): Fountain Creek segment COARFO02a includes the mainstem from its confluence with Monument Creek to the State Highway 47 Bridge. This segment was assigned an ambient-based chronic selenium standard of 8.0 ug/L during the Arkansas River Basin RMH in 2007. The Aquatic Life Use-based acute standard was set at TVS. Two acute exceedances were found during the data assessment for this rulemaking hearing that could place this segment on the 303(d) List. Further investigation of these acute exceedances showed discrepancies in the USGS and the WQCD data. The Division, as well as Colorado Springs, believed that because of the inconsistent nature of this data it may not be representative, and together the parties will investigate the validity of these data. For this reason, the Commission placed this segment on the M&E as opposed to the 303(d) List until further study of selenium in this segment can take place.

8. Upper Colorado segment 2, Shadow Mountain Reservoir (COUCUC02): The Division originally proposed to include Shadow Mountain Reservoir on the 2008 303(d) List for dissolved oxygen. In their RPHS, Northern opposed the listing of Shadow Mountain for dissolved oxygen on the 303(d) List. They stated that the data was not representative because it was not spatially distributed, it did not have temporal variability, and it followed a temporary event, namely fall turn over following a historic drought. The Division disagreed regarding the representative nature of the sampling program but points out that there are questions about the validity of the September 2003 sample profile that was evaluated. For example, the Division believed that D.O. readings taken on September 16, 2003 may have been a calibration error. Moreover, that was the only reading that exceeded the standard during the entire period of record and thus may not have been representative. For these reasons the reservoir was placed on the M&E List as opposed to the 303(d) List until further evaluation can take place.

9. Upper Colorado segments 6 and 8, Camp Cr, Jones Gulch, Keystone Cr, and Mozart Creek (COUCBL06 and COUCBL08): During the 2004 rulemaking process, the four identified tributaries in these two segments were placed on the M&E List based upon measured pH levels during one spring one runoff season when pH levels are expected to be relatively low due to natural causes. Subsequent water quality monitoring conducted over a period of four years has found that these streams meet the pH standards and have 15th percentile values that are above the minimum 6.5 s.u. pH standard. Based upon these findings, the Commission removed segments COUCBL06 and COUCBL08 from the M&E List.

Code of Colorado Regulations 59 10. Upper Colorado segment 10 (COUCUC10): The Division proposed that segment COUCUC10 be placed on the M&E List for copper based on data from WQCD station 12193, located on the Fraser River at the Town of Fraser. Additional stations were assessed on this segment. The Districts questioned the data used in the assessment and upon reevaluation of data for five stations along the Fraser River, the Division revised its proposal to only list a portion of the segment on the M&E List. The WQCC placed the Fraser River from the Town of Fraser to the confluence with the Colorado River on the M&E List based on this data analysis. The Division will work with the Grand County Districts and the Grand County Water Information Network (GCWIN) to collect more data and look into copper issues on the Fraser River. PARTIES TO THE RULEMAKING HEARING 1. The Metro Wastewater Reclamation District 2. Bear Creek Watershed Association 3. Keystone Resort 4. City of Colorado Springs and Colorado Springs Utilities 5. CAM-Colorado LLC and CAM Mining LLC 6. Colorado Division of Wildlife 7. Southeastern Colorado Water Conservancy District 8. Shell Frontier Oil and Gas, Inc.

9. The Grand County Water and Sanitation District #1, the Winter Park West Water and Sanitation District, the Fraser Sanitation District and the Winter Park Sanitation District 10. Trout Unlimited, Colorado Trout Unlimited, and the Evergreen Chapter of Trout Unlimited 11. Northern Colorado Water Conservancy District 12. Seneca Coal Company 13 Colorado River Water Conservation District 14. U.S. Environmental Protection Agency, Region 8 15. City of Black Hawk and Black Hawk/Central City Sanitation District 16. Cripple Creek & Victor Gold Mining Company 17. Town of Minturn 18. Homestake Mining Company of California 19. CBS Operations Inc

93.13 STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE; FEBRUARY,

2010 RULEMAKING, EFFECTIVE DATE OF APRIL 30, 2010 Code of Colorado Regulations 60 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. Consolidation of Regulations #93 and #94 Prior to the 2010 listing cycle, Colorado’s list of Water-Quality-Limited Segments Requiring Total Maximum Daily Loads was set forth in this Regulation #93, and Colorado's Monitoring and Evaluation List was set forth in Regulation #94. In this hearing, the Commission has approved the Division staff proposal to combine both lists into Regulation #93, and to repeal the former Regulation #94. The primary benefit of combining the regulations is to make the status of water segments in Colorado easier to understand by setting forth both lists in one table. This new structure will also make it easier to understand proposed revisions to either list during future rulemaking hearings. These benefits will be seen by the Division, the Commission and interested stakeholders.

Both regulations were heard by the Commission at the same rulemaking hearings in the past and decisions were made for both regulations at the same time. One reason for maintaining separate lists in the past is that Colorado’s list of Water-Quality-Limited Segments Requiring Total Maximum Daily Loads is subject to EPA approval, while Colorado's Monitoring and Evaluation List is not. Although the Commission is now combining both lists into one regulation for simplicity and ease of use, it will continue to be only the list of Water-Quality-Limited Segments Requiring Total Maximum Daily Loads that requires EPA approval. In submitting the revised "Section 303(d) List" to EPA, the Commission will note that only that list is submitted for approval and that the separate Colorado Monitoring and Evaluation List is maintained as state-only information.

B. 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 promulgated in 2008. 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.

2. List Development a. Listing Methodology The "Section 303(d) Listing Methodology - 2010 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 on May 11, 2009.

1. This Listing Methodology sets forth the criteria that generally were used to make decisions regarding which waters to include on the 2010 Section 303(d) List and the 2010 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.

Code of Colorado Regulations 61 b. Information Considered The Commission has considered all existing and readily available information in developing the 2010 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 2010 listing decisions. Such information will be considered in the next listing cycle.

c. Data Quality In the Division's Quality Management Plan 2007 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." In order to meet this goal, the WQCD required that all information submitted in response to its August 2009 call for data have a certification of quality included with the data. All of the information received for this data call that was utilized to develop assessments for this rulemaking hearing had a quality certification submitted or has been identified as not having this certification. Only a small fraction of the data is not certified.

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 2010 Section 303(d) Listing Methodology.

4. Fish Consumption Advisory Listings The 2010 Section 303(d) Listing Methodology, states:

1. Fish Consumption Advisories are issued by the Colorado Department of Public Health and Environment ("CDPHE") in instances where analysis of fish tissue samples provides documentation of a public health risk. Issuance of a FCA by CDPHE indicates impairment of an Aquatic Life Use classification for any waters so classified. The Commission has included 17 segments on the 2010 303(d) List for non-attainment of the aquatic life use due to mercury fish consumption advisories for 22 lakes or reservoirs. The Commission also included 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. The following segments have been added to the 2010 303(d) List due to new Fish Consumption Advisories:

- Lower Gunnison Segment 4b, Juniata Reservoir - Lower Colorado Segment 20, Rifle Gap Reservoir Code of Colorado Regulations 62 - San Juan Segment 6a, Echo Canyon Reservoir - Upper Colorado Segment 12, Lake Granby - Yampa River Segment 2b, Elkhead Reservoir, Catamount Lake 5. New Table Value Standards Cadmium and Zinc: As part of the Basic Standards hearing of 2005, new zinc and cadmium table values were adopted. The acute and chronic zinc and cadmium equations in each basin were modified to conform to Regulation No. 31 over the last four years. An increase in cadmium listings were the result of a more stringent cadmium standard.

The following segments were added to the 303(d) List for cadmium: - Big Thompson Segment 2 - Clear Creek Segments 2a, 2b, 2c, 9b, 11, 13b - Cache la Poudre Segment 7 - Upper South Platte Segments 2b, 2c, 5a, 5b, 15 - Blue River Segment 12 - Eagle River Segment 5c - Upper South Platte Segments 3 (Hawkins Gulch), 5a Temperature: As part of the Temperature Standards hearing of 2007, new temperature table values were adopted. The acute and chronic temperature standards in the Upper and Lower Colorado and the South Platte River Basins were modified to conform to Regulation No. 31 over the last two years.

The following segments were added to the 303(d) List for temperature: - Upper Colorado Segments 3, 4, 7b and 10c 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 ug/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 proposed for listing based on exceedances of the standards: - Lower South Platte Segment 1: Manganese 7. Relisting Segments with Approved TMDLs Due to Standards Changes Code of Colorado Regulations 63 Once a TMDL has been completed, impaired waters are removed from the 303(d) List and placed into Integrated Reporting Category 4a. TMDLs are written to the adopted standards at the time they are submitted to EPA. As standards are periodically reviewed they may become more stringent. In these cases the TMDL may no longer be protective of the current standards. The Division reviewed segments where both TMDLs have been written and new, more restrictive standards have been adopted by the Commission. The Commission has relisted the following segments:

South Platte Basin:

- Clear Creek Segments 09b, 11, and 13b: Cadmium - Clear Creek Segment 02b: Zinc - Upper South Platte Segments 2b, 2c and 15: Cadmium 8. Delisting of Segments with Recently Approved TMDLs The Division submitted 64 TMDLs to EPA in the last biennium that have been approved. The following segments and parameters have been removed from the 303(d) List: - Upper Arkansas Segment 2a: Zinc - Upper Arkansas Segments 2b, 2c and 3: Cadmium and Zinc - Upper Arkansas Segment 5: Lead and Cadmium - Upper Arkansas Segment 7: Zinc - Upper Arkansas Segment 11: pH, Aluminum, Cadmium, Copper and Zinc - Upper Arkansas Segment 12a: Lead and Zinc - San Miguel Segment 3a: Zinc - San Miguel Segment 3b: Cadmium and Zinc - San Miguel Segments 6a and 6b: Zinc - Uncompahgre Segments 2, 3a, 6a: Cadmium, Copper, Iron, and Zinc - Rio Grande Segment 4: Cadmium and Zinc - Rio Grande Segment 30, Sanchez Reservoir: Aquatic Life Use (Hg FCA) - Closed Basin Segment 9a: Cadmium - Closed Basin Segment 9b: Copper - Dolores River Segment 9: Cadmium and Zinc - Boulder Creek Segment 4a: pH, Cadmium, Copper and Zinc - Clear Creek Segment 2: Copper and Zinc Code of Colorado Regulations 64 - Clear Creek Segment 3a: Zinc - Clear Creek Segment 3b: Lead and Zinc - Clear Creek Segment 9a: Copper - Clear Creek Segment 9b: Copper, Lead and Zinc - Clear Creek Segment 11: Lead and Zinc - Clear Creek Segment 13b: Total Recoverable Iron, Manganese, Zinc, and Aquatic Life Use - Upper South Platte Segment 4: Copper - Upper South Platte Segment 5b: Zinc - Blue River Segment 6: pH, Cadmium, Copper, Lead and Zinc - Blue River Segment 7: pH, Cadmium, Copper, Lead, Manganese and Zinc - Blue River Segment 12: Zinc - Eagle River Segment 5a: Copper and Zinc - Eagle River Segment 5b: Zinc - Eagle River Segment 5c: Zinc - Eagle River Segment 7b: Copper and Zinc 9. 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:

- Upper Arkansas Segment 2a: NO - Uncompahgre River Segment 14, Sweitzer Lake: D.O.

- Lower Colorado Segment 3: Total Recoverable Iron - White River Segment 13b, Corral Creek: Selenium - La Plata Segment 4a: Zinc - Rio Grande Grande Segment 9 (Beaver Creek Reservoir): D.O. - Closed Basin Segment 6, San Luis Lake: D.O.

- Cherry Creek Segment 2, Cherry Creek Reservoir: chlorophyll a - Upper Colorado Segment 7a: Total Recoverable Iron - Yampa River Segment 16: Total Recoverable Iron Code of Colorado Regulations 65 - Lower Yampa Segment 20: E. coli - Cache La Poudre Segment 14 (Horsetooth Reservoir): D.O. - Upper Colorado Segment 5 (Wolford Reservoir): D.O.

10. Dissolved Oxygen Standard in Lakes and Reservoirs In 2008, the Commission directed the Division to work with outside parties and stakeholders on changes to the Listing Methodology with regards to the assessment of dissolved oxygen in lakes and reservoirs. Refinement of assessment methods were discussed in workgroup meetings and updates to the dissolved oxygen methods were included in the 2010 Listing Methodology. The revised 2010 Listing Methodology states that if the average temperature in the epilimnion of lakes and reservoirs exceeds the temperature standard, temperature and dissolved oxygen below the epilimnion will be evaluated for adequate refuge. Refuge is defined as the concurrent attainment of the temperature and dissolved oxygen standard at lower depths. If adequate refuge is not present in a single profile, the segment is listed as impaired for dissolved oxygen rather than for temperature. The Commission added the following segments to the 303(d) List due to exceedances of the temperature standard where adequate refuge was not found: - Lower Arkansas Segment 5b, Trinidad Lake - Clear Creek Segment 17a, Arvada Reservoir The Listing Methodology also states that if the average dissolved oxygen concentration in the epilimnion falls below the standard in any profile, the lake will be placed on the 303(d) list. Where the dissolved oxygen standard is not attained in the metalimnion, but it is attained in the epilimnion, the lake may be placed on the M&E list, according to the Listing Methodology. The Commission added 25 new lakes to the M&E list due to exceedances in the dissolved oxygen standard in the metalimnion. The following twelve lakes and reservoirs were added to the 303(d) List due to exceedances in the dissolved oxygen standard in the epilimnion: - Cache la Poudre Segment 20, Seaman Reservoir - Middle South Platte Segment 4, Milton Reservoir - Middle South Platte Segment 7, Prospect Lake - Upper South Platte Segment 17a, Berkeley Lake, Duck Lake - Upper South Platte Segment 17b, Sloan’s Lake - Upper South Platte Segment 23, Barnum Lake, Garfield Lake, Harvey Lake, Parkfield Lake and Houston Lake - Upper Colorado Segment 2, Shadow Mountain Lake The dissolved oxygen standard is slated for revisions in the 2010 Basic Standards and Methodology, Regulation No. 31, rule-making hearing in June 2010. The attainment decision for these lakes and reservoirs may be different when they are reassessed with the revised standard.

11. Seasonal Listings of E. Coli Code of Colorado Regulations 66 The 2010 Listing Methodology included a provision to allow assessment of the E. coli standard on a seasonal basis. The Division proposed the following segments be placed on the 303(d) List based on seasonal impairments of the E. coli standard:

- Arkansas River Basin, Fountain Creek Segments 2b and 6 - South Platte Basin, Big Thompson Segment 9 - South Platte Basin, Cache la Poudre Segments 12 and 13a - South Platte Basin, Bear Creek Segment 2 - South Platte, Clear Creek Segment 15 - South Platte, Upper South Platte Segment 16c: Harvard, West Harvard and Lakewood Gulches The Commission adopted all proposed seasonal listings onto the 303(d) List as proposed by the Division.

12. Listing of Segments where Water Quality is not Meeting Standards not Identified Above The following segments were added to the 303(d) List due to exceedances of water quality standards not identified above:

- South Platte, Bear Creek Segment 5: Swede Gulch/Kerr Gulch, E. coli - South Platte, Cherry Creek Segment 3: E. coli and Se - South Platte, Clear Creek Segment 2b: Zn - South Platte, Clear Creek Segment 3a: Cu - South Platte, Clear Creek Segment 9a: Silver Creek, Cu and Pb - South Platte, Clear Creek Segment 9b: pH - Upper Gunnison Segment 29a, Deadman Gulch: pH, Cd, Cu, Mn, Zn, Fe(Trec) - Lower Colorado Segment 10: Se - Lower Colorado, White River Segment 9d: Se - South Platte, Bear Creek Segment 1c (Bear Creek Reservoir): Chl a, Phosphorus - South Platte, Bear Creek Segment 5: E. coli - South Platte, Boulder Creek Segment 2a, 2b and 3: Cu - South Platte, Boulder Creek Segment 8: Se - South Platte, Boulder Creek Segment 9: As - South Platte, Big Thompson Segment 2: Cu, Zn - South Platte, Big Thompson Segment 3, 6, 7: Cu Code of Colorado Regulations 67 - South Platte, Big Thompson Segment 4a, 4b: Se - South Platte, Big Thompson Segment 8: D.O - South Platte, Big Thompson Segment 16 (Lake Estes): Cu - South Platte, Cache La Poudre Segment 7: Pb - South Platte, Cache La Poudre Segment 11: Se - South Platte, Lower South Platte Segment 1: Se, Mn - South Platte, Lower South Platte Segment 2b: Se - South Platte, Middle South Platte Segment 1a: E. coli - South Platte, Middle South Platte Segment 1b: Se - South Platte, Middle South Platte Segment 4 (Barr and Milton Reservoirs): NH - South Platte, Middle South Platte Segment 7 (Horse Creek Reservoir and Prospect Lake): pH, NH - South Platte, Republican Segment 4: E. coli - South Platte, St. Vrain Segment 2a: Zn - South Platte, St. Vrain Segment 4c: Cu, As - South Platte, Upper South Platte Segment 2c: Zn - South Platte, Upper South Platte Segment 3 (Hawkins Gulch): Se - South Platte, Upper South Platte Segment 3 (Horse Creek): D.O., Fe(trec) - South Platte, Upper South Platte Segment 3 (West Creek): As, Hg - South Platte, Upper South Platte Segment 3 (Goose Creek): D.O. - South Platte, Upper South Platte Segment 3 (Trail & Wigwam Creeks): Fe(trec) - South Platte, Upper South Platte Segment 4: pH - South Platte, Upper South Platte Segment 5a: Cu, Zn - South Platte, Upper South Platte Segment 5c: NH - South Platte, Upper South Platte Segment 14: As - South Platte, Upper South Platte Segment 17a (Berkeley Lake): As - South Platte, Upper South Platte Segment 23 (Barnum Lake): E. coli - Upper Colorado,Yampa River Segment 13b: Total Recoverable Iron Code of Colorado Regulations 68 13. Segment- Specific Issues a. Upper South Platte Segment 15 and Middle South Platte Segment 1a – Category 4b Demonstration Plan Metro Wastewater Reclamation submitted a Category 4b Demonstration Plan to the Division for two segments on the mainstem of the South Platte: Upper South Platte Segment 15 and Middle South Platte Segment 1a. Category 4b is an alternative to listing an impaired segment on the 303(d) List. A Category 4b Demonstration Plan, when implemented, must ensure attainment with all applicable water quality standards through pollution control mechanisms within a reasonable time period. This plan was accepted by the U.S. Environmental Protection Agency prior to the development of the Division's proposed 303(d) List. As a result, the Division did not include these segments in their proposal. No further discussion or comments were received by other parties. The Commission did not include Upper South Platte Segment 15 and Middle South Platte Segment 1a on the 303(d) List for ammonia and nitrate, for which the Category 4b Demonstration Plan was written. The Commission expects that after a reasonable period of time as defined in the Category 4b Demonstration Plan, water quality will be reexamined on these segments. If water quality standards are not achieved at this time the segment will be considered impaired and placed on the 303(d) List.

b. South Platte River (COSPUS14 and COSPUS15) - Trash Two proposals were originally submitted in prehearing statements by P.U.R.E. and Wild Earth Guardians to list the South Platte River from Bowles Avenue to the confluence of Sand Creek as impaired for trash. Wild Earth Guardians withdrew their proposal but P.U.R.E maintained their proposal. The Division met prior to the Rulemaking hearing with representatives of P.U.R.E and discussed the issue. The Division maintained that a method to determine impairment for trash did not exist and that this must be determined before a decision of impairment can be made. The Division and P.U.R.E agreed to begin to address this issue in the 2012 303d Listing Methodology development stakeholder process that is to begin in the summer of 2010.

1. After listening to all of the testimony on this topic, the Commission took no action on listing these segments for trash at this time. It is expected that P.U.R.E, the Division and other stakeholders will work collaboratively to develop an appropriate methodology for determining impairment for trash through the 2012 303d Listing Methodology development process and other appropriate collaborative processes.

c. Muddy Creek (COUCUC07b) – Temperature The Division proposed to list Muddy Creek (COUCUC07b) on the 303(d) List for temperature. The River Water Conservation District (River District) opposed this listing stating that exceedances at an upper station were due to a temporary construction at the outlet of Wolford Reservoir. Exceedances were still found at the lower station. The Commission adopted the Division’s alternate proposal to include the upper portion from Wolford Reservoir to Cow Gulch on the M&E List the and lower portion from Cow Gulch to the Colorado River on the 303(d) List.

d. Colorado River (COUCUC03) – Temperature Code of Colorado Regulations 69 The Division proposed to place all of the Colorado River mainstem from Lake Granby to the Roaring Fork River (COUCUC03) on the 303(d) List for temperature exceedances. Northern Colorado River Conservancy District (Northern) proposed an alternative portion of 578 Road bridge to the William Fork confluence. The Commission found that the portion that Northern recommended, omitted sites with exceedances both above and below their recommended portion. To encompass the entire scope of temperature exceedances, the Commission adopted the portion from 578 Road to immediately above the confluence with the Blue River.

e. Lower Colorado Segment 2b – Selenium In 2008, the Commission adopted only the portion at Humphrey Backwaters Area onto the 303(d) List for selenium. For this cycle, the Division proposed to list the entire segment for selenium. The City of Grand Junction and the River District opposed this listing claiming that the Riverwatch data used in the assessment was not representative or of good quality. The Division supported the quality of this data but since the data was older than five years, the Division agreed that additional data collection was needed before a decision to list the entire segment could be made. The Commission placed the remainder of this segment on the M&E List while leaving the Humphrey Backwaters Area on the 303(d) List. Grand Junction and the River District have offered to collect data throughout the segment before the next 303(d) rulemaking hearing in 2012.

f. Upper South Platte Segment 16c Upper South Platte Segment 16c is an all tributary segment and the Division proposed to place the entire segment on the 303(d) List for exceedances of E. coli and selenium.

1. E. coli: Denver Environmental Health (DEH) opposed listing all tributaries for both parameters. DEH put forward an alternative proposal for E. coli on this segment with some tributaries to be included on the 303(d) annually, some listed seasonally and one for the M&E List based on the attainment conclusions for each tributary individually. Those tributaries attaining the standard were not proposed for either list. The Division reviewed their proposal and agreed that it is a reasonable approach for E. coli. The Commission adopted the alternative proposal as presented by DEH. Selenium: DEH also asked that the Commission to only list those tributaries that have selenium data on the 303(d) List. The Division opposed this alternative proposal. The Division pointed out that unlike the data found on E. coli for these tributaries, everywhere that selenium data was collected, exceedances were found. The Commission chose to place the entire segment on the 303(d) List for selenium.

g. Fountain Creek Segments 2a and 2b The Division originally proposed to change the E. coli listing on Segment 2a from annual to seasonal (May through October) and to add Segment 2b to the 303(d) List seasonally. Rocky Mountain Environmental Labor Coalition/Sierra Club and Bill Thiebaut, District Attorney for the 10th Judicial District, asked that the listing be considered for the entire year for both segments as there are recreation uses in Fountain Creek year round. Through further investigation and reassessment of the data by the Division and the parties, data indicates that in Segment 2a, the E. coli standards are exceeded annually as opposed to seasonally as originally thought. In Segment 2b the exceedances were only found from May – October. The Commission chose to retain the listing on Segment 2a for E. coli annually and to add Segment 2b to the 303(d) List from May-October. Code of Colorado Regulations 70 The Division also originally proposed to remove the selenium listings on Segment 2a and 2b. This proposal also received opposition from RMELC/Sierra Club and Bill Thiebaut as there are ongoing studies regarding selenium in Fountain Creek. Colorado Springs supported the Division’s original proposal. Further investigation of acute selenium exceedances in Segment 2b in July 2005 prompted the Division and EPA to change their position prior to the hearing to retain this segment on the 303(d) List. The Commission agreed that this listing should remain on the 303(d) List until further evidence exist to support delisting. The Commission agreed with the Division that the data is meeting the ambient based standards in Segment 2a and removed the M&E listing for that segment.

h. Bear Creek (COSPBE05) – Swede Gulch and Kerr Gulch - E. coli The Division originally proposed to list only Swede Gulch based on the Division’s sampling at the mouth of the gulch. The Bear Creek Watershed Association (BCWA) identified this sampling location as Kerr Gulch. The Division used USGS and other maps indicating this as Swede Gulch. The Colorado Department of Transportation (CDOT) and residents identify this as Kerr Gulch. The Division met with the BCWA and agreed that the watershed, whatever the name of the stream, may be impacted by septic systems and livestock. The BCWA agreed to the development and implementation of a monitoring plan in the watershed to identify E. coli sources. The Division agreed that if the plan were implemented the priority of the listing should be changed from high to low to allow time for sampling and development of stakeholder involvement. The Commission agreed with the Division and the BCWA’s plan for Swede Gulch and Kerr Gulch.

i. Clear Creek (COSPCL14b) – Manganese The Division proposed to add manganese to the list of impairment parameters of Clear Creek segment 14b. During the 2009 South Platte River Basin RMH a new site-specific manganese standard was established for the segment. In the development of the new site-specific standard for segment 14b, data from both Clear Creek segments 14a and 14b were combined to determine a single standard for both segments. This procedure was used since segment 14a has very limited data and it was felt averaging would establish a more realistic standard. As it turns out when segment 14b only data is assessed against the new standard developed using data from both segments, the few samples from segment 14a with a lower ambient manganese concentration skewed the development of the site-specific standard enough that segment 14b data exceeds the new standard.

1. Based on the fact that the segment 14b site-specific standard was developed using data from the upstream segment it is not possible to evaluate if the segment is in attainment of the manganese standard. The proper site-specific standard indicating ambient conditions should be equivalent to the current assessment value and would not indicate impairment since they are the same dataset.

   After reviewing the development of the segment 14b site-specific manganese standard, the Division agreed with MillerCoors that the Clear Creek segment should not be listed for exceeding the manganese standard. The Commission agreed with the Division and MillerCoors that Clear Creek segment 14b should not be listed for manganese.

j. Juniata Reservoir (COGULG04a)

Code of Colorado Regulations 71 The Division originally proposed to list Juniata Reservoir on the 303(d) List for impairment of the Aquatic Life Use due to a Fish Consumption Advisory (FCA). A mercury FCA was issued for Juniata Reservoir in 2009. The Section 303(d) Listing Methodology 2010 Listing Cycle states at III.D.6 "Issuance of a FCA by CDPHE indicates impairment of an Aquatic Life Use classification for any waters so classified." The City of Grand Junction and Colorado Division of Wildlife proposed to either close the reservoir or change the reservoir to "catch and release" in order for the Division to remove the FCA and therefore remove the basis for inclusion on the 303(d) List. The Division stated that the FCA would not be lifted if the reservoir changed to catch and release and the only way that the FCA could be lifted at Juniata is if the reservoir was completely fenced and fishing access was prohibited. At the time of the hearing, no action had been taken and the FCA was still in effect. Therefore the Commission chose to add this segment to the 303(d) List.

k. Marston Reservoir (COSPUS22)

1. The Division proposed that Marston Reservoir as part of COSPUS22 be placed on the M & E List for non-attainment of the DO standard in the metalimnion. The Denver Water Board argued that Marston was not waters of the state and was not used for aquatic life uses. There was discussion about what constitutes waters of the state and it was decided that that decision was not appropriate for this hearing, since this hearing addresses all waters for which classifications and standards have been adopted. The Commission decided to include Marston Reservoir on the 2010 M & E List because it fits within the description of waters in Upper South Platte segment 22.

C. Revisions to Monitoring and Evaluation List 1. Introduction This regulation updates Colorado’s Monitoring and Evaluation List (M&E List) to reflect additional water quality information available since the Regulation was promulgated in 2008.

2. List Development See the discussion of list development under subsection B.2 above.

3. Prioritization and Scheduling The Division remains committed to establishing a plan for monitoring and evaluating these water bodies 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. Data Quality See the discussion of data quality under subsection B.2.c above.

5. New Table Value Standards Cadmium and Zinc: As part of the Basic Standards hearing of 2005, new zinc and cadmium table values were adopted. The acute and chronic zinc and cadmium equations in each basin were modified to conform to Regulation No. 31 over the last four years. An increase in cadmium listings were the result of a more stringent cadmium standard.

The following segments were added to the M&E List for cadmium: Code of Colorado Regulations 72 - Gunnison River, San Miguel Segment 3a - South Platte, Boulder Creek Segment 14, Barker Reservoir - Boulder Creek Segments 2a, 2b, 3, 9 10 and 14 - Clear Creek Segment 6, Hoop Creek - Cache la Poudre Segment 13a - Upper South Platte Segment 3, Hawkins Gulch - Cache La Poudre Segment 9 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 ug/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 proposed for listing based on exceedances of the standards: - Upper Colorado, Yampa River Segments 2a: Manganese - Upper Colorado, Yampa River Segments 3: Manganese and Dissolved Iron 7. 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 M&E List due to attainment of current water quality standards:

- Fountain Creek Segment 2a: Selenium - Fountain Creek Segment 3, Bear Creek and Cheyenne Creek: Sediment - Middle Arkansas Segment 14: E. coli - Upper Arkansas Segment 5, Turquiose Lake: D.O.

- Upper Arkansas Segment 13: Sediment - Lower Colorado Segment 4a: Selenium - Lower Colorado Segment 11h: Total Recoverable Iron - Lower Colorado Segment 13b: D.O. and E. coli - St. Vrain Segment 2: Sediment - St. Vrain Segment 3: E. coli Code of Colorado Regulations 73 - Upper South Platte Segment 2a: Sediment - Upper South Platte Segment 3: Sediment and Temperature - Upper South Platte Segment 4 (North Fork South Platte and Buffalo Creek): Sediment - Upper South Platte Segment 6a: Sediment - Upper Colorado, Yampa River Segment 3 (First Creek): Sediment - Upper Colorado, Yampa River Segment 19 (Oliver Creek): Sediment - Upper Colorado, North Platte River Segment 4a: Sediment - Gunnison River, Uncompahgre Segment 3b, Ridgway Reservoir: D.O. - Gunnison River, San Miguel Segment 7a: Total Recoverable Iron - Lower Colorado, White River Segment 22: Sediment - Upper Colorado, Blue River Segment 18: E. coli 8. 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:

- Lower Arkansas Segment 5b: D.O.

- San Miguel Segment 3a: Cadmium - Upper Gunnison Segment 29a, Deadman Gulch: Cd, Cu, Mn, Zn, Fe(Trec) - Big Thompson Segment 4b: Selenium - Boulder Creek Segment 8: Selenium - Upper Colorado Segment 12, Shadow Mountain Lake: D.O. - Upper Colorado, Yampa River Segment 3 (Bushy Creek): Sediment - Upper South Platte 5a: Cadmium, copper and zinc 9. Dissolved Oxygen Standard in Lakes and Reservoirs In 2008 the Commission directed the Division to work with parties in 2008 and 2009 on changes to the Listing Methodology in regards to dissolved oxygen. Refinement of assessment methods were discussed in workgroup meetings and included in the 2010 Listing Methodology. The dissolved oxygen standard is slated for revisions in the 2010 Basic Standards and Methodology, Regulation No. 31, RMH in June 2010.

Code of Colorado Regulations 74 The following segments were added to the M&E List due to exceedances of the dissolved oxygen standard in the metalimnion in at least one profile:

- Gunnison River, Uncompahgre Segment 14, Sweitzer Lake - Rio Grande Segment 9, Beaver Creek Reservoir - Big Dry Creek Segment 2, Standley Lake - Boulder Creek Segment 14, Barker Reservoir - Big Thompson Segment 12, Lake Loveland, Horseshoe Lake and Boyd Lake - Big Thompson Segment 14, Lon Hagler Reservoir and Lonetree Reservoir - Cache la Poudre Segment 14, Horsetooth Reservoir - Lower South Platte Segment 3, North Sterling Reservoir - Middle South Platte Segment 4, Barr Lake - Middle South Platte Segment 7, Horse Creek Reservoir - St. Vrain Creek Segment 7, Boulder Reservoir - St. Vrain Segment 9, Union Reservoir - St. Vrain Segment 13, Lake Thomas - Upper South Platte Segment 16b, Aurora Reservoir - Upper South Platte Segment 19, Tarryall Reservoir, Cheesman Reservoir, Elevenmile Reservoir, Spinney Mountain Reservoir - Upper South Platte Segment 22, Marston Reservoir, Quincy Reservoir, - Upper South Platte Segment 23, Vanderbilt Reservoir - Upper Colorado Segment 5, Wolford Mountain Reservoir - Upper Colorado, Yampa River Segment 2b, Stagecoach Reservoir PARTIES TO THE RULEMAKING HEARING 1. Protect Urban River Environments (Confluence Kayaks and Telemark, Colorado Whitewater Association, Denver Trout Unlimited, The Shimoda Group, The Greenway Foundation) 2. Summit Water Quality Committee 3. Northwest Colorado Council of Governments 4. City of Boulder 5. City of Colorado Springs and Colorado Springs Utilities Code of Colorado Regulations 75 6. City of Aurora 7. Denver Water 8. City and County of Denver 9. Bear Creek Watershed Association 10. City of Grand Junction 11. Northern Colorado Water Conservancy District 12. Metro Wastewater Reclamation District 13. Alamosa Riverkeeper 14. Bill Thiebaut, District Attorney for 10th Judicial District, Colorado 15. Farmers Reservoir and Irrigation Company 16. Barr Lake and Milton Reservoir Watershed Association 17. Colorado Division of Wildlife 18. City of Black Hawk and Black Hawk/Central City Sanitation District 19. Cherry Creek Basin Water Quality Authority 20. South Platte Coalition for Urban River Evaluation 21. Colorado River Water Conservation District 22. Grand County Water and Sanitation District #1, Winter Park Ranch Water and Sanitation District, Fraser Sanitation District, Winter Park Sanitation District 23. City of Westminster 24. The Rocky Mountain Environmental Labor Coalition and the Sierra Club 25. Colorado Stormwater Council 26. Seneca Coal Company 27. Littleton/Englewood Wastewater Treatment Plant 28. City of Arvada 29. MillerCoors LLC 30. Ute Water Conservancy District, acting by and through the Ute Water Activity Enterprise 31. US Environmental Protection Agency

93.14 STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE; DECEMBER

2011 RULEMAKING, EFFECTIVE DATE OF MARCH 30, 2012 Code of Colorado Regulations 76 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.

1. 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. Code of Colorado Regulations 77 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) Code of Colorado Regulations 78 - 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:

Code of Colorado Regulations 79 - 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)

Code of Colorado Regulations 80 - 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 Code of Colorado Regulations 81 - 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. Code of Colorado Regulations 82 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 Code of Colorado Regulations 83 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) Code of Colorado Regulations 84 - 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: SO (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: NH (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) Code of Colorado Regulations 85 - 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)

Code of Colorado Regulations 86 - 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: SO , 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) Code of Colorado Regulations 87 - 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) Code of Colorado Regulations 88 - South Platte, Clear Creek Segment 17b, Ralston Creek: U (COSPCL17b) - South Platte, Upper South Platte Segment 17a, Smith Lake: NH (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) Code of Colorado Regulations 89 - 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) Code of Colorado Regulations 90 - 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 Code of Colorado Regulations 91 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, NH (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 Code of Colorado Regulations 92 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. Code of Colorado Regulations 93 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):

Code of Colorado Regulations 94 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.

1. 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 Code of Colorado Regulations 95 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 Code of Colorado Regulations 96 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 _______________________________________________________________________________ Editor’s Notes History Entire rule eff. 04/30/2008.

Entire rule eff. 04/30/2010.

Rules 93.1, 93.2, 93.3, 93.14 eff. 03/30/2012.

Code of Colorado Regulations 97