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Drinking water / CO

PFAS in Colorado drinking water

165 Colorado public water systems tested under UCMR5. 39 detected at least one PFAS compound; 126 detected none at the reporting thresholds. Values are the highest single result per compound, in ng/L (parts per trillion). The federal limit for PFOA and PFOS is 4 ng/L.

Water systemServesHighest results (ng/L)Reading
ARAPAHOE CNTY WWWA

CO0203002

ArapahoePFPeA 7.9PFHxA 6.8PFBS 6.1PFBA 5.5above final limit
BRIGHTON CITY OF

CO0101025

AdamsPFPeA 19.3PFOS 10.6 *PFBA 10.6PFHxA 9.4above final limit
CHEROKEE MD

CO0121125

El PasoPFPeA 19.8PFHxA 17.6PFBS 7.6PFOA 6.1 *above final limit
GUNNISON CITY OF

CO0126325

GunnisonPFHxA 7.2PFPeA 5.1PFOS 4.2 *PFBS 3above final limit
LITTLE THOMPSON WD

CO0135477

LarimerPFOA 4.8 *above final limit
MOUNTAIN VILLAGE TOWN OF

CO0157400

San MiguelPFHxS 8.1PFOS 7.5 *above final limit
PARKER WSD

CO0118040

DouglasPFPeA 14PFHxA 11.9PFBA 8.6PFOA 4.8 *above final limit
ROCKY FORD CITY OF

CO0145600

OteroPFBS 8.5PFHxS 6PFOS 4.1 *above final limit
SNAKE RIVER WD

CO0159105

SummitPFOS 22 *PFHxS 13PFPeA 8PFBS 6.6above final limit
STONEGATE MD

CO0118076

DouglasPFOA 5.6 *PFOS 5.1 *PFBS 3.9PFHxA 3.8above final limit
THORNTON CITY OF

CO0101150

AdamsPFHxA 12.6PFPeA 12.4PFBA 10.4PFBS 8.1above final limit
TODD CREEK VILLAGE MD

CO0101157

AdamsPFBS 38PFHxA 8.7PFOS 6.8 *PFBA 6.8above final limit
WIDEFIELD WSD

CO0121900

El PasoPFHxA 140.6PFPeA 108.9PFBA 42PFHxS 28.4above final limit
AURORA CITY OF

CO0103005

ArapahoePFBA 7.8PFPeA 7.2PFHxA 5.6PFBS 3.3detected
CASTLE PINES NORTH MD

CO0118006

DouglasPFBA 6.4PFPeA 3.8PFBS 3.3PFHxA 3.2detected
CASTLE ROCK TOWN OF

CO0118010

DouglasPFBA 5.1PFPeA 4.7detected
CENTENNIAL WSD

CO0118015

DouglasPFBA 8.7PFPeA 5.7PFHxA 5.1PFBS 5detected
CHIPETA WD

CO0143176

MontrosePFBA 29.5detected
CONSOLIDATED MUTUAL MAPLE GROVE

CO0130020

JeffersonPFBS 4PFHxA 3.8PFPeA 3.5detected
COTTONWOOD WSD

CO0118020

DouglasPFPeA 6.2PFBA 5.6PFHxA 5.4PFBS 4.7detected
CSU FOOTHILLS CAMPUS

CO0235182

LarimerPFBA 5.9detected
DELTA CITY OF

CO0115205

DeltaPFBA 8.3detected
EAST CHERRY CREEK VALLEY WSD

CO0103035

ArapahoePFBA 6.2PFPeA 4.7detected
ENGLEWOOD CITY OF

CO0103045

ArapahoePFBA 6.4PFPeA 5.8PFBS 5.8PFHxA 5.5detected
FOUNTAIN CITY OF

CO0121275

El PasoPFPeA 76.7PFHxA 50.8PFBA 33.8detected
GRAND COUNTY WATER NO 1

CO0125323

GrandPFBA 11.8detected
INVERNESS WSD

CO0203012

ArapahoePFBA 6.9detected
LAMAR CITY OF

CO0150700

ProwersPFBS 4.7PFHxS 3.3detected
LOCHBUIE TOWN OF

CO0162486

WeldPFPeA 6.8PFBS 6.3PFHxA 5.6PFHxS 3detected
MORRISON TOWN OF

CO0130085

JeffersonPFHxA 4.4PFBS 3detected
NORTHERN DOUGLAS COUNTY WSD

CO0118016

DouglasPFBA 8PFPeA 5.7PFHxA 5.3PFBS 5.3detected
PINERY WWD

CO0118025

DouglasPFPeA 9.6PFHxA 8.1PFBA 5.8PFBS 5.3detected
SECURITY WSD

CO0121775

El PasoPFPeA 63.6PFBA 35.4PFHxA 6.7detected
SILVERTHORNE TOWN OF

CO0159095

SummitPFBS 5.9PFHxS 3.7detected
SOUTH ADAMS COUNTY WSD

CO0101140

AdamsPFPeA 11.4PFBA 9.5PFHxA 4.4detected
ST CHARLES MESA WD

CO0151750

PuebloPFBA 13detected
STRATMOOR HILLS WSD

CO0121800

El PasoPFHxA 42PFPeA 27PFBA 16.1PFHpA 5.1detected
SUBURBAN WATER

CO0143515

MontrosePFBA 8detected
WOODMOOR WSD

CO0121950

El PasoPFBS 3.3detected

* exceeds the final federal MCL for that compound. Detections of compounds whose limits EPA proposed to rescind in May 2026 are shown for information.

Systems with no PFAS detected

126 tested systems reported no PFAS above the laboratory reporting limits. Each has its own page with its sampling detail.

A detection at the system level does not tell you what reaches one specific tap: levels vary by entry point, treatment train and plumbing. A certified lab test of your own tap settles it. Testing and treatment options