Systems reaching a study comparison level
2.9%4 of 136 active community water systems with complete monitoring
All 136 systems had complete monitoring. 4 reached at least one study comparison level; 132 did not. “Study comparison level” means the dated EPA technical cutoff used in this January 2026 research release. It does not determine household exposure, health risk, or current legal compliance.
Check your area
Find your water system
ZIP codes are used only to route visitors to public water systems that reported serving them. Confirm the actual provider using a water bill or utility record.
Compound summary
System counts in Colorado
Each count shows how many included water systems reached the named study level.
| Study comparison | Systems reaching level | Water systems included | Percent |
|---|---|---|---|
| PFOA: study level 4.05 ppt (April 2024 EPA level: 4 ppt) | 1 | 136 | 0.7% |
| PFOS: study level 4.05 ppt (April 2024 EPA level: 4 ppt) | 4 | 136 | 2.9% |
| PFHxS: study level 15 ppt (April 2024 EPA level: 10 ppt) | 1 | 136 | 0.7% |
| PFNA: study level 15 ppt (April 2024 EPA level: 10 ppt) | 0 | 136 | 0.0% |
| HFPO-DA: study level 15 ppt (April 2024 EPA level: 10 ppt) | 0 | 136 | 0.0% |
| Hazard Index: study level 1.5 with at least two detected components (April 2024 EPA level: 1) | 1 | 136 | 0.7% |
System directory
Community water systems with complete monitoring
Each PWSID appears once, preventing double counting across ZIP associations.
| Public water system | PWSID | Population served | Primary source | Sampling locations | Study comparison |
|---|---|---|---|---|---|
| ADVENIR FRENCH QUARTER | CO0116104 | 3,447 | Surface water purchased | 1 | Below the study levels |
| ALAMOSA CITY OF | CO0102100 | 11,271 | Ground water | 1 | Below the study levels |
| ANTONITO TOWN OF | CO0111100 | 981 | Groundwater under influence of surface water | 1 | Below the study levels |
| ARAPAHOE CNTY WWWA | CO0203002 | 31,000 | Ground water | 7 | Below the study levels |
| ARVADA CITY OF | CO0130001 | 171,610 | Surface water | 2 | Below the study levels |
| ASPEN CITY OF | CO0149122 | 31,100 | Surface water | 1 | Below the study levels |
| AURORA CITY OF | CO0103005 | 533,407 | Surface water | 3 | Below the study levels |
| BERTHOUD TOWN OF | CO0135138 | 14,211 | Surface water | 1 | Below the study levels |
| BLACK HAWK CITY OF | CO0124147 | 15,167 | Surface water | 2 | Below the study levels |
| BOULDER CITY OF | CO0107152 | 166,080 | Surface water | 2 | Below the study levels |
| BRECKENRIDGE TOWN OF | CO0159020 | 28,315 | Surface water | 1 | Below the study levels |
| BRIGHTON CITY OF | CO0101025 | 56,304 | Surface water purchased | 4 | Reached a study level |
| BROOMFIELD CITY AND COUNTY OF | CO0107155 | 106,153 | Surface water | 1 | Below the study levels |
| BUENA VISTA TOWN OF | CO0108300 | 3,776 | Groundwater under influence of surface water | 2 | Below the study levels |
| BURLINGTON CITY OF | CO0132005 | 3,720 | Ground water | 2 | Below the study levels |
| CANON CITY CITY OF | CO0122100 | 34,800 | Surface water | 1 | Below the study levels |
| CASTLE PINES VILLAGE MD | CO0118005 | 5,656 | Ground water | 2 | Below the study levels |
| CASTLE ROCK TOWN OF | CO0118010 | 110,298 | Surface water | 5 | Below the study levels |
| CENTENNIAL WSD | CO0118015 | 103,444 | Surface water | 3 | Below the study levels |
| CENTRAL CITY CITY OF | CO0124171 | 3,750 | Surface water | 1 | Below the study levels |
| CHEROKEE MD | CO0121125 | 29,610 | Ground water | 3 | Below the study levels |
| CHIPETA WD | CO0143176 | 3,802 | Surface water purchased | 1 | Below the study levels |
| CLIFTON WD | CO0139180 | 34,500 | Surface water | 1 | Below the study levels |
| COLORADO SPRINGS UTILITIES | CO0121150 | 464,111 | Surface water | 6 | Below the study levels |
| CONSOLIDATED MUTUAL MAPLE GROVE | CO0130020 | 81,400 | Surface water | 1 | Below the study levels |
| COPPER MOUNTAIN CONSOLIDATED MD | CO0159030 | 5,785 | Ground water | 2 | Below the study levels |
| COTTONWOOD WSD | CO0118020 | 10,867 | Surface water purchased | 2 | Below the study levels |
| CRAIG CITY OF | CO0141188 | 8,930 | Surface water | 1 | Below the study levels |
| CRAWFORD MESA WA | CO0115189 | 486 | Ground water | 1 | Below the study levels |
| CREEDE CITY OF | CO0140500 | 1,965 | Ground water | 1 | Below the study levels |
| DACONO CITY OF | CO0162200 | 6,900 | Surface water purchased | 1 | Below the study levels |
| DELTA CITY OF | CO0115205 | 8,700 | Surface water purchased | 1 | Below the study levels |
| DENVER WATER BOARD | CO0116001 | 1,287,000 | Surface water | 4 | Below the study levels |
| DOLORES TOWN OF | CO0142400 | 1,626 | Surface water | 1 | Below the study levels |
| DONALA WSD | CO0121175 | 6,421 | Surface water purchased | 3 | Below the study levels |
| DURANGO CITY OF | CO0134150 | 33,787 | Surface water | 1 | Below the study levels |
| EAGLE RIVER WSD | CO0119802 | 51,515 | Surface water | 11 | Below the study levels |
| EAGLE TOWN OF | CO0119233 | 7,511 | Surface water | 2 | Below the study levels |
| EAST CHERRY CREEK VALLEY WSD | CO0103035 | 66,130 | Surface water purchased | 4 | Below the study levels |
| EAST LARIMER COUNTY WD | CO0135233 | 27,944 | Surface water purchased | 1 | Below the study levels |
| ENGLEWOOD CITY OF | CO0103045 | 57,332 | Surface water | 1 | Below the study levels |
| ERIE TOWN OF | CO0162255 | 47,444 | Surface water | 1 | Below the study levels |
| ESTES PARK TOWN OF | CO0135257 | 16,722 | Surface water | 2 | Below the study levels |
| EVANS CITY OF | CO0162260 | 19,369 | Surface water purchased | 1 | Below the study levels |
| EVERGREEN MD | CO0130030 | 15,750 | Surface water | 1 | Below the study levels |
| FEDERAL HEIGHTS CITY OF | CO0101055 | 11,678 | Surface water purchased | 2 | Below the study levels |
| FIRESTONE TOWN OF | CO0162476 | 27,798 | Surface water purchased | 1 | Below the study levels |
| FOUNTAIN CITY OF | CO0121275 | 25,130 | Surface water purchased | 4 | Below the study levels |
| FRISCO TOWN OF | CO0159055 | 4,495 | Surface water | 3 | Below the study levels |
| FT COLLINS CITY OF | CO0135291 | 179,901 | Surface water | 1 | Below the study levels |
| FT COLLINS LOVELAND WD | CO0135292 | 63,532 | Surface water purchased | 2 | Below the study levels |
| FT LUPTON CITY OF | CO0162291 | 12,099 | Surface water | 1 | Below the study levels |
| FT MORGAN CITY OF | CO0144005 | 12,000 | Surface water | 1 | Below the study levels |
| GENESEE WSD | CO0130035 | 3,920 | Surface water | 1 | Below the study levels |
| GLENWOOD SPRINGS CITY OF | CO0123314 | 9,428 | Surface water | 1 | Below the study levels |
| GOLDEN CITY OF | CO0130040 | 38,288 | Surface water | 1 | Below the study levels |
| GRAND COUNTY WATER NO 1 | CO0125323 | 5,400 | Surface water | 2 | Below the study levels |
| GRAND JUNCTION CITY OF | CO0139321 | 26,000 | Surface water | 1 | Below the study levels |
| GREELEY CITY OF | CO0162321 | 132,310 | Surface water | 2 | Below the study levels |
| GUNNISON CITY OF | CO0126325 | 9,610 | Ground water | 9 | Below the study levels |
| GYPSUM TOWN OF | CO0119329 | 15,272 | Surface water | 2 | Below the study levels |
| HAYDEN TOWN OF | CO0154333 | 3,982 | Surface water | 1 | Below the study levels |
| IDAHO SPRINGS CITY OF | CO0110020 | 10,432 | Surface water | 1 | Below the study levels |
| INVERNESS WSD | CO0203012 | 8,140 | Surface water purchased | 6 | Below the study levels |
| JOHNSTOWN TOWN OF | CO0162418 | 27,295 | Surface water | 1 | Below the study levels |
| LA JUNTA CITY OF | CO0145420 | 8,320 | Ground water | 1 | Below the study levels |
| LAFAYETTE CITY OF | CO0107473 | 28,700 | Surface water | 2 | Below the study levels |
| LAMAR CITY OF | CO0150700 | 7,500 | Ground water | 1 | Below the study levels |
| LEFT HAND WD | CO0107471 | 20,280 | Surface water | 2 | Below the study levels |
| LIMON TOWN OF | CO0137015 | 5,080 | Ground water | 1 | Below the study levels |
| LITTLE THOMPSON WD | CO0135477 | 25,654 | Surface water purchased | 1 | Below the study levels |
| LOCHBUIE TOWN OF | CO0162486 | 6,518 | Ground water | 1 | Below the study levels |
| LONGMONT CITY OF | CO0107485 | 104,178 | Surface water | 1 | Below the study levels |
| LOUISVILLE CITY OF | CO0107487 | 20,975 | Surface water | 2 | Below the study levels |
| LOVELAND CITY OF | CO0135485 | 91,077 | Surface water | 2 | Below the study levels |
| MANITOU SPRINGS CITY OF | CO0121450 | 6,938 | Surface water | 1 | Below the study levels |
| MENOKEN WD | CO0143506 | 4,500 | Surface water purchased | 1 | Below the study levels |
| MERIDIAN MD | CO0218015 | 23,415 | Surface water purchased | 3 | Below the study levels |
| MERIDIAN SERVICE MD | CO0121455 | 12,760 | Ground water | 1 | Below the study levels |
| MID VALLEY MD | CO0119508 | 4,588 | Ground water | 3 | Below the study levels |
| MONTE VISTA CITY OF | CO0153600 | 4,600 | Ground water | 3 | Below the study levels |
| MONTEZUMA WC | CO0142900 | 13,797 | Surface water | 1 | Below the study levels |
| MONTROSE CITY OF | CO0143518 | 19,305 | Surface water purchased | 1 | Below the study levels |
| MONUMENT TOWN OF | CO0121475 | 5,740 | Ground water | 6 | Below the study levels |
| MORGAN COUNTY QUALITY WD | CO0144020 | 8,116 | Surface water purchased | 3 | Below the study levels |
| MORRISON TOWN OF | CO0130085 | 9,887 | Surface water | 1 | Below the study levels |
| MOUNTAIN VILLAGE TOWN OF | CO0157400 | 9,700 | Ground water | 4 | Below the study levels |
| MT WERNER WD | CO0154524 | 19,000 | Surface water | 2 | Below the study levels |
| NEW CASTLE TOWN OF | CO0123538 | 5,024 | Surface water | 1 | Below the study levels |
| NORTH TABLE MOUNTAIN WSD | CO0130105 | 10,000 | Surface water | 1 | Below the study levels |
| NORTH WELD COUNTY WD | CO0162553 | 15,890 | Surface water purchased | 2 | Below the study levels |
| NORTHERN COLORADO WA | CO0135554 | 4,675 | Surface water purchased | 3 | Below the study levels |
| NORTHERN DOUGLAS COUNTY WSD | CO0118016 | 6,160 | Surface water purchased | 1 | Below the study levels |
| NORTHGLENN CITY OF | CO0101115 | 48,927 | Surface water | 1 | Below the study levels |
| PAGOSA AREA WSD | CO0104300 | 11,069 | Surface water | 3 | Below the study levels |
| PAINT BRUSH HILLS | CO0221690 | 4,994 | Ground water | 2 | Below the study levels |
| PARK CENTER WD | CO0122600 | 4,000 | Surface water | 1 | Below the study levels |
| PARKER WSD | CO0118040 | 75,949 | Surface water | 11 | Below the study levels |
| PARKVILLE WD | CO0133700 | 7,500 | Surface water | 2 | Below the study levels |
| PATTERSON VALLEY WC | CO0145540 | 96 | Ground water | 1 | Below the study levels |
| PERRY PARK WSD | CO0118045 | 3,890 | Groundwater under influence of surface water | 3 | Below the study levels |
| PINERY WWD | CO0118025 | 12,901 | Surface water purchased | 6 | Below the study levels |
| PUEBLO BOARD OF WW | CO0151500 | 114,070 | Surface water | 1 | Below the study levels |
| PUEBLO WEST MD | CO0151650 | 30,000 | Surface water | 3 | Below the study levels |
| RIFLE CITY OF | CO0123676 | 9,489 | Surface water | 1 | Below the study levels |
| ROCKY FORD CITY OF | CO0145600 | 4,443 | Ground water | 1 | Below the study levels |
| ROXBOROUGH WSD | CO0118055 | 13,765 | Surface water | 1 | Below the study levels |
| SALIDA CITY OF | CO0108700 | 5,666 | Surface water | 3 | Below the study levels |
| SECURITY WSD | CO0121775 | 20,000 | Surface water purchased | 3 | Below the study levels |
| SILVERTHORNE TOWN OF | CO0159095 | 8,400 | Ground water | 4 | Below the study levels |
| SNAKE RIVER WD | CO0159105 | 9,900 | Ground water | 2 | Reached a study level |
| SNOWMASS VILLAGE WSD | CO0149717 | 6,353 | Surface water | 1 | Below the study levels |
| SOUTH ADAMS COUNTY WSD | CO0101140 | 75,559 | Surface water purchased | 5 | Below the study levels |
| STEAMBOAT SPRINGS CITY OF | CO0154725 | 9,950 | Surface water purchased | 1 | Below the study levels |
| STERLING CITY OF | CO0138045 | 15,100 | Groundwater under influence of surface water | 1 | Below the study levels |
| STONEGATE MD | CO0118076 | 15,295 | Surface water purchased | 1 | Below the study levels |
| SUPERIOR MD NO 1 | CO0107725 | 17,900 | Surface water | 1 | Below the study levels |
| TELLURIDE TOWN OF | CO0157800 | 7,900 | Surface water | 2 | Below the study levels |
| THORNTON CITY OF | CO0101150 | 226,465 | Surface water | 2 | Below the study levels |
| TODD CREEK VILLAGE MD | CO0101157 | 7,363 | Groundwater under influence of surface water | 1 | Reached a study level |
| TRI COUNTY WCD | CO0143755 | 20,490 | Surface water purchased | 1 | Below the study levels |
| TRINIDAD CITY OF | CO0136800 | 11,400 | Surface water | 1 | Below the study levels |
| TWO RIVERS VILLAGE | CO0119720 | 896 | Ground water | 1 | Below the study levels |
| US AIR FORCE ACADEMY | CO0121845 | 16,876 | Surface water purchased | 1 | Below the study levels |
| US DEPARTMENT OF THE ARMY FORT CARSON | CO0221445 | 48,000 | Surface water purchased | 1 | Below the study levels |
| UTE WCD | CO0139791 | 92,580 | Surface water | 1 | Below the study levels |
| WELLINGTON TOWN OF | CO0135838 | 11,720 | Surface water | 2 | Below the study levels |
| WEST FORT COLLINS WD | CO0135290 | 4,000 | Surface water purchased | 1 | Below the study levels |
| WESTMINSTER CITY OF | CO0101170 | 202,078 | Surface water | 2 | Below the study levels |
| WIDEFIELD WSD | CO0121900 | 27,640 | Surface water purchased | 9 | Reached a study level |
| WINDSOR TOWN OF | CO0162843 | 23,500 | Surface water purchased | 3 | Below the study levels |
| WOODMEN HILLS MD | CO0121930 | 13,888 | Ground water | 3 | Below the study levels |
| WOODMOOR WSD | CO0121950 | 18,031 | Surface water | 5 | Below the study levels |
| YMCA ROCKIES WIND RIVER | CO0135883 | 3,730 | Surface water purchased | 1 | Below the study levels |
| YMCA SNOW MTN RANCH | CO0125916 | 578 | Groundwater under influence of surface water | 1 | Below the study levels |
| YUMA CITY OF | CO0163020 | 4,049 | Ground water | 6 | Below the study levels |
How the count works
What is included
Each active community water system with complete monitoring is counted once, even if it is linked with several ZIP codes. Private wells are excluded, and UCMR 5 did not comprehensively monitor every small system. This page does not apply Colorado's state-specific standards or determine compliance. Use the official state or territory drinking-water program for current regulatory information.