How many water violations are in Adams County?

Adams County has 11,205 total drinking water violations across 86 water systems, of which 474 are health-based violations. 86.0% of systems have at least one violation.

How many people get water from Adams County systems?

Water systems in Adams County serve approximately 711,442 people through 86 public water systems.

Has PFAS been detected in Adams County water?

Under EPA UCMR5, 4 of 7 tested systems in Adams County had at least one PFAS detection (57.1% of the UCMR5-tested subset - not of all 86 SDWIS systems).

What types of water sources supply Adams County?

Water systems in Adams County use GW (48 systems), SW (38 systems) as their primary water sources.

Are health-based violations serious?

Health-based violations indicate that drinking water exceeded Maximum Contaminant Levels (MCLs) set by the EPA or failed treatment technique requirements. 4.2% of Adams County's violations are health-based. Among counties with any SDWIS violations, this extract puts Adams County in the lower health-based share band. Not all violations indicate immediate health risk, but they require corrective action.

Where does Adams County sit among U.S. counties for water-system population?

According to EPA SDWIS county population served used on /counties, Adams County ranks #97 of 3,254 counties by people served, and #4 of 64 counties in Colorado. Ordinals use the same total_population DESC sort as the counties directory. See /methodology#corpus-placement.

Counties → Colorado

Adams County, Colorado

Compiled by PlainWater · May 15, 2026

SDWIS compliance plate

Sheet CO001 · Adams County 86 sys · 11,205 viol · #97/3254

VIOL-SEVERE · HEALTH-LOW · RANK-TOP · ABOVE-PEER · PFAS-HIGH · SRC-GW · SYS-MID · BOOK-FULL

VIOL-SEVERE 86.0% flagged
HEALTH-LOW 4.2% health
RANK-TOP #97/3254
ABOVE-PEER +1.1 pp
PFAS-HIGH 57.1% detect
SRC-GW GW lead 56%
SYS-MID 86 systems
BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Jefferson County ( -1.1 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Adams County ranks #97 of 3,254 counties by people served, and #4 of 64 counties in Colorado. See methodology · corpus placement.

Adams County standing, lower-flagged corpus third

Flagged-system rate 86.0% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 4.2% is health-based share at or below the lower third (≤ 10.3%) . UCMR5 detect rate 57.1% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #97 of 3,254 · #4 of 64 in Colorado.

Water Systems

System Name	Population	Violations	PFAS
Thornton City Of	226,465	36	Detected
Westminster City Of	202,078	18	Clean
South Adams County WSD	74,341	0	Detected
Brighton City Of	56,304	89	Detected
Northglenn City Of	48,927	7	Clean
Crestview WSD	23,756	0	-
North Washington Street WSD	14,500	6	-
Federal Heights City Of	11,678	4	Clean
Todd Creek Village MD	7,202	68	Detected
Bennett Town Of	4,400	62	-
Wikiup MHP	2,500	161	-
North Pecos WSD	2,500	0	-
Eastern Adams Co MD	2,485	12	-
Strasburg WSD	2,050	64	-
Kimberly Hills MHP	2,005	49	-
Pine Lakes Ranch	1,905	14	-
Friendly Village of Aurora MHP	1,786	0	-
Woodland Hills Mhc	1,740	8	-
Hillcrest Village MHP	1,505	51	-
Eastgate Village Manufactured Homes	1,500	22	-
Redwood Estates	1,500	0	-
The Grove at Alta Ridge	1,300	53	-
Greatrock North WSD	1,250	89	-
Denver Cascade MHP	1,200	16	-
Holiday Hills Village	1,190	1	-
Casa Estates MHP	1,117	6	-
Friendly Village of the Rockies	1,046	11	-
Adams County Parks	868	519	-
Countryside Village of Denver	863	31	-
Mile High WC	700	102	-
Lamplighter MHP	651	9	-
Barr Lake State Park	609	46	-
Watkins Square	515	61	-
Franklin Mobile Home Park	513	32	-
Belleview Christian College	460	215	-
Mountain View Fellowship	447	3	-
Avilla Eastlake	410	76	-
HI Land Acres WSD	350	18	-
Green Acres MHP	325	89	-
Mountain View Wua	320	57	-
Chaparral Village MHP	303	4	-
Thornton Estates	300	2	-
Cavanaugh Hills WS	286	208	-
Hazeltine Heights Water	261	286	-
Garden Meadows	250	0	-
Pioneer Mobile Home Park	250	0	-
Johnson Auto Plaza	247	17	-
Buffalo Run Golf Course	240	4	-
Riverdale Peaks II MD	209	26	-
Mile High Mobile Home Park	209	12	-

Compare beyond Colorado

Lower-flagged peers for Adams County

Cross-state counties nearest Adams County on flagged-system share (86.0%) and cumulative violation count (11,205). In-state neighbours stay on the compliance plate above.

Similar flagged-system rate

Nearest cross-state counties by % of SDWIS systems with at least one violation on record.

4 peers

Similar violation load

Nearest cross-state counties by cumulative SDWIS violation count (all systems in the county).

4 peers

Read our methodology · Check your water system - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater

Compiled by PlainWater, Drinking Water Quality Editorial Process · May 15, 2026

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.