How many water violations are in Canyon County?

Canyon County has 9,692 total drinking water violations across 143 water systems, of which 1,918 are health-based violations. 95.1% of systems have at least one violation.

How many people get water from Canyon County systems?

Water systems in Canyon County serve approximately 214,619 people through 143 public water systems.

Has PFAS been detected in Canyon County water?

Under EPA UCMR5, 0 of 3 tested systems in Canyon County had at least one PFAS detection (0.0% of the UCMR5-tested subset - not of all 143 SDWIS systems).

What types of water sources supply Canyon County?

Water systems in Canyon County use GW (143 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. 19.8% of Canyon County's violations are health-based. Among counties with any SDWIS violations, this extract puts Canyon County in the middle health-based share band. Not all violations indicate immediate health risk, but they require corrective action.

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

According to EPA SDWIS county population served used on /counties, Canyon County ranks #318 of 3,254 counties by people served, and #2 of 44 counties in Idaho. Ordinals use the same total_population DESC sort as the counties directory. See /methodology#corpus-placement.

Counties → Idaho

Canyon County, Idaho

Compiled by PlainWater · May 15, 2026

SDWIS compliance plate

Sheet ID027 · Canyon County 143 sys · 9,692 viol · #318/3254

VIOL-SEVERE · HEALTH-LOW · RANK-TOP · PHOTO-FINISH · PFAS-CLEAN · SRC-GW · SYS-LARGE · BOOK-FULL

VIOL-SEVERE 95.1% flagged
HEALTH-LOW 19.8% health
RANK-TOP #318/3254
PHOTO-FINISH ±0.5 pp
PFAS-CLEAN 0.0% detect
SRC-GW GW lead 100%
SYS-LARGE 143 systems
BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Bonneville County (+ 0.5 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Canyon County ranks #318 of 3,254 counties by people served, and #2 of 44 counties in Idaho. See methodology · corpus placement.

Canyon County standing, mid-flagged corpus third

Flagged-system rate 95.1% is in the corpus middle third (≤ 100.0% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 19.8% is health-based share in the middle third (≤ 24.5%) . UCMR5 detect rate 0.0% is UCMR5 detect rate at or below the tested-pool lower third (≤ 0.0%) . Population served ranks #318 of 3,254 · #2 of 44 in Idaho.

Water Systems

System Name	Population	Violations	PFAS
Nampa City Of	100,200	262	Clean
Caldwell City Of	74,000	518	Clean
Middleton City Of	13,190	81	Clean
Parma City Of	2,250	13	-
Wilder City Of	1,690	31	-
Caldwell Housing Authority	1,100	86	-
Greenleaf City Of	846	52	-
Farmway Lds Church	784	5	-
Lds Building 30 Hwy 30	775	35	-
Deer Flat Lds Church	718	2	-
Sorrento Lactalis	700	46	-
Nampa Northside Lds Church	684	0	-
Lds Lansing Lane	614	5	-
Melba City Of	576	101	-
Notus City Of	539	109	-
Sunnyridge Lds Church	539	9	-
Jackson Food Store 178	500	9	-
West Canyon Elementary School	467	41	-
Simplot Potato	450	112	-
Purple Sage Elementary	410	4	-
Shalimar Subd	370	18	-
Belle Aire Acres 2	350	61	-
Lansing Meadows	320	10	-
Flamingo West	320	0	-
Chase Crossing	306	0	-
El Rancho Heights	300	193	-
Lakeys Cafe and Trailer Park	300	85	-
Parma Motor Vu	300	35	-
Evergreen Mobile Park	284	72	-
United Reformed Church of Nampa	260	15	-
Covert Water Users Association	250	133	-
Rolling Hills Estates Water Company	250	122	-
Woodview Acres Property Owners	245	63	-
Sunnyridge 3 Water Corp	240	10	-
Sunlight Terrace	234	87	-
Indian Village	225	175	-
Cti Food Service	216	35	-
Karcher Ranchette Water Corp	213	68	-
Faith Journey Church	205	0	-
Somerset West Water Corp	203	65	-
Shortstop Inc	200	58	-
Owyhee Village Subd Water Assn Inc	200	26	-
Purple Sage Golf Course	200	46	-
Extra Mile #196	200	3	-
Church of God of Prophecy	200	0	-
Woodgrain Millwork	200	0	-
Caldwell Christian Church	175	36	-
Timberstone HOA	170	5	-
Lakeview Hills Water Users Association	160	115	-
Camelot Water Assn Inc	157	20	-

Compare beyond Idaho

Mid-flagged peers for Canyon County

Cross-state counties nearest Canyon County on flagged-system share (95.1%) and cumulative violation count (9,692). 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.