Water Quality in Colorado

1,048 water systems • 313 cities • EPA SDWIS Data

1,048
Water Systems
42,596
Total Violations
5,256
Health-Based Violations
7,175,420
Population Served

Overview

Colorado has 1,048 active community water systems serving 7,175,420 people. These systems have accumulated 42,596 EPA Safe Drinking Water Act violations on record, of which 5,256 are health-based violations (meaning a contaminant exceeded safe levels).

Common contaminants found in violations: Chlorine, TTHM, Selenium, Chlorine Dioxide, E. coli, Nitrate, Stage 2 DBP, Disinfection Byproducts, Barium, HAA5.

Cities with Most Violations in Colorado

# City Violations Health-Based Water Systems Population
1 Colorado Springs 2,017 110 36 567,087
2 Durango 1,243 77 36 47,184
3 Windsor 1,133 55 16 29,533
4 Monte Vista 958 5 2 4,636
5 Carbondale 840 121 18 8,113
6 Hotchkiss 704 46 7 3,765
7 Divide 655 78 7 2,853
8 Crawford 655 28 5 1,469
9 Manzanola 651 413 4 967
10 Rocky Ford 649 313 8 6,028

Largest Cities in Colorado

# City Population Violations Water Systems
1 Denver 1,359,013 428 22
2 Aurora 604,019 367 13
3 Colorado Springs 567,087 2,017 36
4 Fort Collins 303,541 137 10
5 Lakewood 260,762 249 54
6 Thornton 230,581 295 5
7 Westminster 203,655 77 3
8 Arvada 173,420 18 3
9 Boulder 170,165 91 9
10 Greeley 141,047 106 8

All Cities in Colorado

City Population Violations Health Violations Contaminants
Denver 1,359,013 428 6 Chlorine, Selenium
Aurora 604,019 367 9 Chlorine, Chlorine Dioxide, Disinfection Byproducts
Colorado Springs 567,087 2,017 110 Chlorine, Chlorine Dioxide, Contaminant 2920 +7 more
Fort Collins 303,541 137 5 Chlorine, Disinfection Byproducts, E. coli +1 more
Lakewood 260,762 249 16 Chlorine, Chlorine Dioxide, Disinfection Byproducts +2 more
Thornton 230,581 295 4 Chlorine
Westminster 203,655 77 2 Chlorine
Arvada 173,420 18 0
Boulder 170,165 91 8 Chlorine, Disinfection Byproducts, Total Haloacetic Acids (HAA5)
Greeley 141,047 106 19 Chlorine, Chlorine Dioxide, Disinfection Byproducts +2 more
Littleton 126,724 142 5 Chlorine, Fecal Coliform
Pueblo 126,713 166 14 Chlorine, Chlorine Dioxide, Fecal Coliform
Grand Junction 117,707 76 0
Castle Rock 115,659 138 36 Chlorine, Disinfection Byproducts, Total Organic Carbon
Broomfield 109,723 48 7 Chlorine, Disinfection Byproducts
Centennial 106,671 232 26 Total Organic Carbon
Longmont 106,066 8 0
Parker 104,687 48 1 HAA5
Highlands Ranch 104,642 22 0
Englewood 100,134 104 28 E. coli, Total Organic Carbon
Loveland 96,801 348 19 Chlorine, E. coli, Fecal Coliform +1 more
Commerce City 74,341 0 0
Brighton 64,569 300 17 Chlorine, Chlorine Dioxide, Stage 2 DBP +1 more
Golden 53,471 31 0
Montrose 51,712 220 7 Chlorine
Vail 51,515 0 0
Northglenn 48,927 0 0
Fort Carson 48,000 13 0
Durango 47,184 1,243 77 Chlorine, Chlorine Dioxide, Contaminant 2920 +5 more
Wheat Ridge 42,275 261 91 Chlorine, Chlorine Dioxide, Disinfection Byproducts +5 more
Berthoud 40,361 79 6 Contaminant 2920, Fecal Coliform
Erie 40,102 128 0
Canon City 38,878 15 4 TTHM
Clifton 35,300 10 1 E. coli
Aspen 32,562 91 1 Chlorine
Lafayette 32,266 285 5 Chlorine, Chlorine Dioxide, E. coli +1 more
Monument 31,378 122 40 Chlorine, Chlorine Dioxide, Fecal Coliform +1 more
Pueblo West 30,215 81 7 Chlorine, E. coli, TTHM
Steamboat Springs 29,846 525 32 Chlorine, Chlorine Dioxide, Contaminant 2920 +5 more
Windsor 29,533 1,133 55 Barium, Chlorine, Fecal Coliform +2 more
Breckenridge 28,315 43 6 Fecal Coliform
Firestone 28,239 20 0
Fountain 26,486 46 1 Chlorine
Johnstown 24,725 87 4 Contaminant 2920, Fecal Coliform
Estes Park 21,949 293 69 Disinfection Byproducts, E. coli, Fecal Coliform +5 more
Louisville 20,975 29 4 E. coli, Fecal Coliform
Evans 20,610 15 0
Niwot 20,280 10 0
Fort Morgan 20,116 26 0
Greenwood Village 19,983 358 21 Chlorine, E. coli, Fecal Coliform
Falcon 18,927 144 1 Disinfection Byproducts
Superior 17,900 9 5 Fecal Coliform
Frederick 17,827 21 1 Chlorine
Evergreen 17,045 251 71 Bromate, Chlorine, Disinfection Byproducts +5 more
Usaf Academy 16,876 27 1 Total Haloacetic Acids (HAA5)
Glenwood Springs 16,675 233 14 Chlorine, Disinfection Byproducts, Fecal Coliform +1 more
Wellington 16,175 66 9 Chlorine, E. coli
Lucerne 15,890 2 0
Dolores 15,423 44 0
Sterling 15,323 126 0
Gypsum 15,272 9 0
Black Hawk 15,167 31 0
Fort Lupton 14,013 265 50 Chlorine, E. coli, Fecal Coliform +1 more
Peyton 13,616 43 2 Disinfection Byproducts
Trinidad 13,361 298 8 Chlorine, Chlorine Dioxide, E. coli +2 more
Castle Pines 12,800 88 0
Alamosa 12,758 496 19 Chlorine, Chlorine Dioxide, E. coli
Pagosa Springs 12,434 309 8 Chlorine, E. coli
Winter Park 12,093 189 8 Chlorine Dioxide, E. coli
Silverthorne 11,778 66 0
Severance 11,733 25 0
Federal Heights 11,678 1 0
Gunnison 10,754 46 0
Rifle 10,601 379 158 Chlorine, HAA5, Haloacetic Acids +1 more
Keystone 10,570 8 1 Disinfection Byproducts
Idaho Springs 10,432 23 0
La Junta 10,097 629 420 Chlorine, E. coli, HAA5 +1 more
Morrison 9,970 42 0
Redvale 9,825 609 0
Cortez 9,556 62 6 Chlorine, E. coli, Stage 2 DBP
Milliken 9,200 23 0
Dillon 9,018 37 0
Craig 8,930 117 0
Telluride 8,830 388 23 Barium, Chlorine, Disinfection Byproducts +1 more
Delta 8,700 1 0
Woodland 8,500 52 1 Stage 2 DBP
Cedaredge 8,151 346 56 Disinfection Byproducts, E. coli, Fecal Coliform +1 more
Lamar 8,138 24 7 Chlorine, Total Organic Carbon
Basalt 8,130 507 8 Chlorine, Chlorine Dioxide, Fecal Coliform
Carbondale 8,113 840 121 Barium, Chlorine, Chlorine Dioxide +3 more
Florence 8,026 85 2 Chlorine, Contaminant 2920
Leadville 7,870 619 1 Chlorine Dioxide
Eagle 7,641 149 4 Chlorine, Gross Alpha
Eaton 7,328 23 3 Chlorine
Manitou Springs 6,938 5 5 Chlorine, E. coli
Dacono 6,900 9 3 Chlorine
Lochbuie 6,830 9 0
Buena Vista 6,581 114 0
New Castle 6,465 24 1 Fecal Coliform
Limon 6,369 13 0
Snowmass Village 6,353 17 3 Fecal Coliform
Rocky Ford 6,028 649 313 Chlorine, Contaminant 1011, Disinfection Byproducts +2 more
Bayfield 5,993 240 20 Chlorine, E. coli, Fecal Coliform +1 more
Salida 5,806 191 3 Chlorine
Copper Mountain 5,785 1 0
Crested Butte 5,668 65 3 Fecal Coliform
Fraser 5,475 122 0
Hillrose 5,432 5 0
Georgetown 5,315 3 0
Edgewater 5,300 1 0
Elizabeth 5,202 36 2 Chlorine
Granby 5,003 62 1 Disinfection Byproducts
Keenesburg 4,936 21 4 TTHM
Frisco 4,694 330 5 Chlorine, Chlorine Dioxide, Disinfection Byproducts
Glendale 4,689 19 0
Monte Vista 4,636 958 5 Barium, Chlorine, Stage 2 DBP
Bennett 4,400 11 0
Walsenburg 4,329 213 30 Chlorine, Chlorine Dioxide, E. coli +3 more
Ault 4,220 15 0
Larkspur 4,165 175 20 Total Organic Carbon
Administrative Contact 4,161 466 12 Chlorine, Chlorine Dioxide, Disinfection Byproducts +2 more
Yuma 4,049 179 0
La Porte 4,000 19 0
Hayden 3,942 383 0
Paonia 3,847 569 42 Chlorine, Chlorine Dioxide, Disinfection Byproducts +2 more
Silt 3,808 85 11 Chlorine, Selenium
Hotchkiss 3,765 704 46 Chlorine, Chlorine Dioxide, Disinfection Byproducts +4 more
Central City 3,750 45 0
Lyons 3,735 87 46 Chlorine Dioxide, Disinfection Byproducts, E. coli +3 more
Burlington 3,720 85 83 Selenium
Watkins 3,702 293 1 Disinfection Byproducts
Mount Crested Butte 3,546 15 0
Hudson 3,500 274 12 TTHM
Cripple Creek 3,491 32 0
Grand Lake 3,371 15 2 Disinfection Byproducts
Penrose 3,149 22 3 Fecal Coliform
Austin 3,100 16 0
Palisade 3,060 51 0
Palmer Lake 3,044 187 40 Chlorine, Chlorine Dioxide, Total Organic Carbon
Olathe 3,015 4 0
Platteville 2,900 14 0
Divide 2,853 655 78 Chlorine, Contaminant 2920, Disinfection Byproducts +3 more
Colorado City 2,755 296 87 Chlorine Dioxide, Contaminant 1008, E. coli +3 more
Mancos 2,690 45 0
Holyoke 2,672 25 1 Chlorine
Center 2,575 24 0
Meeker 2,551 57 4 Disinfection Byproducts
Rangely 2,495 21 0
Woodland Park 2,447 221 49 Chlorine, Chlorine Dioxide, Disinfection Byproducts +1 more
Las Animas 2,439 25 1 Chlorine Dioxide
Kremmling 2,409 39 5 Chlorine Dioxide, E. coli
Nederland 2,406 7 3 Disinfection Byproducts
Silverton 2,387 6 1 Chlorine
Los Angeles 2,379 28 1 Chlorine
Akron 2,379 15 2 Chlorine
Wray 2,342 15 0
Ordway 2,303 52 1 Chlorine
Crestone 2,299 44 2 Chlorine
Strasburg 2,205 73 14 Chlorine, Chlorine Dioxide, HAA5
Flagler 2,160 16 2 Selenium
Kersey 2,101 8 0
Wiggins 2,049 382 11 Chlorine, Chlorine Dioxide, E. coli
Lasalle 2,010 45 0
Westcliffe 1,994 19 0
Creede 1,965 21 0
El Jebel 1,962 29 1 Fecal Coliform
Edwards 1,959 56 12 TTHM
Conifer 1,941 8 3 E. coli
Wiley 1,905 617 412 HAA5, Total Organic Carbon
Oak Creek 1,750 109 30 E. coli, Fecal Coliform, Stage 2 DBP
Norwood 1,700 20 0
Ouray 1,660 156 3 Chlorine, Fecal Coliform
Deer Trail 1,648 9 0
Farmington Hills 1,500 1 0
Crawford 1,469 655 28 Chlorine, Chlorine Dioxide, Disinfection Byproducts +2 more
Poncha Springs 1,467 7 4 Disinfection Byproducts
Del Norte 1,429 31 2 Chlorine
Springfield 1,378 15 5 Chlorine, Haloacetic Acids, Selenium
Ignacio 1,351 51 5 Chlorine, Fecal Coliform
Ridgway 1,350 66 15 Fecal Coliform
La Veta 1,325 107 32 Chlorine, Fecal Coliform, Total Haloacetic Acids (HAA5)
Parachute 1,320 15 0
Calhan 1,317 125 3 Chlorine, Selenium
Indian Hills 1,300 28 6 E. coli, Fecal Coliform
San Luis 1,275 240 5 Chlorine, Disinfection Byproducts, Stage 2 DBP
Holly 1,226 171 58 Arsenic, Chlorine, Total Organic Carbon
Julesburg 1,225 23 4 HAA5
Minturn 1,200 9 1 E. coli
Antonito 1,171 163 10 Chlorine, Chlorine Dioxide, Disinfection Byproducts +2 more
Fowler 1,169 26 12 Fecal Coliform, HAA5
Fairplay 1,159 45 3 Fecal Coliform
South Fork 1,152 250 3 Chlorine, Chlorine Dioxide
Gilcrest 1,150 6 1 Disinfection Byproducts
Pierce 1,094 4 0
Log Lane Village 1,006 18 0
Byers 1,000 2 0
Manassa 976 49 0
Manzanola 967 651 413 Chlorine, Chlorine Dioxide, HAA5 +2 more
Haxtun 963 92 0
Stratton 960 71 5 Chlorine, Chlorine Dioxide
Beulah 927 187 81 Chlorine, Chlorine Dioxide, Contaminant 2920 +5 more
Debeque 911 79 3 TTHM
Kiowa 910 24 0
Hugo 885 62 1 Stage 2 DBP
Nucla 875 203 17 Chlorine, E. coli, Fecal Coliform +1 more
Sanford 850 0 0
Dove Creek 850 25 10 E. coli, Fecal Coliform, Stage 2 DBP +1 more
Cheyenne Wells 840 43 5 Barium, Chlorine, Selenium
La Jara 825 27 0
York 789 125 0
Bailey 783 49 2 Chlorine
Williamsburg 775 33 0
Rye 745 184 100 Chlorine, Chlorine Dioxide, Disinfection Byproducts +4 more
Ft Morgan 705 138 47 Chlorine, Chlorine Dioxide, Disinfection Byproducts +1 more
Hot Sulphur Springs 687 19 0
Collbran 678 4 0
Bloomfield Hills 666 33 0
Swink 660 5 2 Chlorine
Eads 656 5 0
Lake City 654 15 1 Fecal Coliform
Walden 652 29 0
Walsh 650 33 23 Chlorine Dioxide, Selenium, Total Organic Carbon
San Francisco 646 78 4 Chlorine
Nathrop 638 12 0
Simla 618 7 0
Otis 600 34 2 Chlorine Dioxide
Naturita 585 66 13 TTHM
Moffat 580 16 1 Chlorine
Tabernash 564 0 0
Woody Creek 544 252 2 Chlorine, Fecal Coliform
Sedalia 525 47 2 Chlorine Dioxide
Granada 515 142 10 Chlorine, Chlorine Dioxide, Stage 2 DBP
Clark 511 198 1 Chlorine
Rockvale 504 31 2 Disinfection Byproducts
Saguache 504 42 0
Empire 500 123 42 Disinfection Byproducts, Fecal Coliform
Snowmass 499 245 32 Chlorine, E. coli, Fecal Coliform
Nunn 499 3 0
Victor 491 76 15 Chlorine Dioxide, E. coli, Total Haloacetic Acids (HAA5)
Ft Garland 477 43 0
Blanca 469 10 0
Red Cliff 469 16 3 Fecal Coliform
Yampa 467 33 10 Chlorine, Fecal Coliform
Alma 460 20 4 Fecal Coliform
Florissant 458 495 18 Chlorine Dioxide, Disinfection Byproducts, Fecal Coliform +1 more
Aguilar 447 36 3 Chlorine Dioxide, Fecal Coliform
Fleming 446 98 1 Chlorine
Brookside 438 12 0
Rico 437 21 4 Disinfection Byproducts, Fecal Coliform
Cimarron 431 14 10 Chlorine, Fecal Coliform, Total Haloacetic Acids (HAA5)
Allenspark 416 105 3 Chlorine Dioxide, Fecal Coliform
Cheraw 408 357 214 Chlorine, HAA5, Stage 2 DBP +1 more
Olney Springs 399 14 2 Chlorine, Disinfection Byproducts
Livermore 395 65 0
Los Altos 379 29 9 Selenium
Mcclave 378 56 12 Total Organic Carbon
Gateway 370 6 0
Romeo 365 129 3 Chlorine
Henderson 351 7 0
Coal Creek 350 6 0
Dinosaur 350 156 3 Disinfection Byproducts
Mesa 330 16 0
Iliff 328 8 0
Placierville 322 18 2 Chlorine
Briggsdale 303 4 0
Elbert 300 21 0
Seibert 296 25 1 Disinfection Byproducts
Peetz 295 54 26 Barium, Chlorine Dioxide
Jamestown 280 96 11 Disinfection Byproducts, E. coli, Fecal Coliform
Redstone 275 30 1 E. coli
Boone 263 54 6 Fecal Coliform, Selenium
Ovid 259 13 1 Barium
Wolcott 257 0 0
Capulin 250 49 2 Chlorine
Hasty 244 54 36 Disinfection Byproducts, HAA5, Total Organic Carbon
Sugar City 240 11 0
Weldona 235 44 20 Disinfection Byproducts, Haloacetic Acids, TTHM
Eckley 235 191 11 Barium, Chlorine Dioxide
Ward 230 8 0
Irvine 229 9 1 Gross Alpha
Sedgwick 227 12 2 Disinfection Byproducts
Las Vegas 213 7 2 Chlorine
Eastlake 200 2 0
Paradox 200 127 42 Chlorine, Chlorine Dioxide, E. coli +1 more
Northbrook 200 410 4 Chlorine, Gross Alpha
Santa Ana 200 14 1 Stage 2 DBP
Bethune 195 14 0
Ophir 193 102 36 Chlorine Dioxide, Fecal Coliform
Crook 182 8 0
Silver Plume 180 23 10 Disinfection Byproducts, Fecal Coliform
Tempe 175 3 1 Stage 2 DBP
Buffalo Creek 175 24 10 Disinfection Byproducts, E. coli, Selenium
Westcreek 165 63 10 Fecal Coliform, Lead
Vona 160 61 2 Gross Alpha, Stage 2 DBP
Hesperus 154 12 0
Genoa 153 197 19 Chlorine, E. coli, Fecal Coliform +1 more
Agate 152 182 9 Chlorine Dioxide
Bristol 151 246 16 Chlorine, E. coli, Total Organic Carbon
Campo 150 23 2 Disinfection Byproducts
Stockton 150 141 1 Chlorine
Sheridan Lake 148 293 35 Chlorine Dioxide, Gross Alpha, Haloacetic Acids +1 more
Vilas 137 42 13 Chlorine, Total Organic Carbon
Branson 131 86 3 Chlorine, Fecal Coliform
Pritchett 125 32 27 Total Organic Carbon
Ramah 125 53 5 Chlorine Dioxide
Cokedale 120 38 1 Chlorine
Kim 116 6 1 Chlorine
Almont 113 33 1 Fecal Coliform
Detroit Lakes 107 3 0
Karval 102 20 3 Chlorine, Selenium
Garcia 100 9 2 Chlorine, Stage 2 DBP
Prairie Village 100 10 2 Chlorine
Somerset 100 59 26 Fecal Coliform, TTHM

Data Sources

Drinking water data from the EPA Safe Drinking Water Information System (SDWIS). Only active community water systems (CWS) serving 100+ people are included.

Verify at epa.gov