How many water violations are in Ravalli County?

Ravalli County has 9,816 total drinking water violations across 129 water systems, of which 1,316 are health-based violations. 93.0% of systems have at least one violation.

How many people get water from Ravalli County systems?

Water systems in Ravalli County serve approximately 30,657 people through 129 public water systems.

Has PFAS been detected in Ravalli County water?

Under EPA UCMR5, 1 of 2 tested systems in Ravalli County had at least one PFAS detection (50.0% of the UCMR5-tested subset - not of all 129 SDWIS systems).

What types of water sources supply Ravalli County?

Water systems in Ravalli County use GW (128 systems), SW (1 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. 13.4% of Ravalli County's violations are health-based. Among counties with any SDWIS violations, this extract puts Ravalli County in the middle health-based share band. Not all violations indicate immediate health risk, but they require corrective action.

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

According to EPA SDWIS county population served used on /counties, Ravalli County ranks #1,349 of 3,254 counties by people served, and #8 of 56 counties in Montana. Ordinals use the same total_population DESC sort as the counties directory. See /methodology#corpus-placement.

Counties → Montana

Ravalli County, Montana

Compiled by PlainWater · May 15, 2026

SDWIS compliance plate

Sheet MT081 · Ravalli County 129 sys · 9,816 viol · #1349/3254

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

VIOL-SEVERE 93.0% flagged
HEALTH-LOW 13.4% health
RANK-MID #1349/3254
PHOTO-FINISH ±0.1 pp
PFAS-HIGH 50.0% detect
SRC-GW GW lead 99%
SYS-LARGE 129 systems
BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Yellowstone County (+ 0.1 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Ravalli County ranks #1,349 of 3,254 counties by people served, and #8 of 56 counties in Montana. See methodology · corpus placement.

Ravalli County standing, mid-flagged corpus third

Flagged-system rate 93.0% is in the corpus middle third (≤ 100.0% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 13.4% is health-based share in the middle third (≤ 24.5%) . UCMR5 detect rate 50.0% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #1,349 of 3,254 · #8 of 56 in Montana.

Water Systems

System Name	Population	Violations	PFAS
Hamilton City Of	5,585	18	Detected
Stevensville Town Of	2,090	76	-
Super One Food Store	1,769	335	-
Town Pump Woodside 1	1,198	16	-
Town Pump Florence 1	1,092	19	-
Florence Carlton School	1,025	70	-
Corvallis Gym and Middle School	900	6	-
Darby Town Of	850	639	-
Oles Country Store	820	37	-
Pinesdale Town Of	800	978	Clean
Lost Trail Rest Area	701	40	-
Lost Trail Powder Mtn Sula	690	61	-
Stokes Market Florence	600	33	-
Lone Pine Store	600	60	-
Gsk Biologicals	560	20	-
Canyons Athletic Club The	500	34	-
Corvallis Primary School	450	73	-
Roots Christian Fellowship	400	0	-
Lds Church Corvallis	320	29	-
Victor Dollar General	303	0	-
Lone Rock School District No 13	280	143	-
Trapper Creek Job Corps	275	233	-
Bowers Market Corvallis	274	43	-
Glens Cafe	223	57	-
Subway Sandwich Shop Hamilton	210	33	-
Florence Coffee Corvallis	207	0	-
Lost Trail Ski Area Yurt System	202	24	-
Bloom Montana	201	101	-
Pharaohplex	200	9	-
Victor Middle School and High School	185	73	-
Kootenai Creek Village	175	56	-
Hamilton Murdochs	164	0	-
Bowers Market Victor	156	39	-
Backyard Tap House	154	3	-
Town Pump Stevensville Ll 1	150	1	-
Hamilton Golf Club Snack Shop	150	77	-
Stock Farm The	150	54	-
Victor Grade School PWS	140	4	-
Bitterroot Health Stevensville	140	0	-
Corvallis Mobile Village	138	106	-
Corvallis Subway	125	6	-
Daly Estates Subdivision	123	92	-
Triple Creek Ranch	120	74	-
Wild Flower HOA, The	120	19	-
Centennial Homeowner's Association, Inc	115	25	-
Montana Frontier Cafe	110	19	-
McNulty Investments	110	5	-
Bear's Lair	107	15	-
Camp Sula	105	48	-
L and M Building	100	26	-

Compare beyond Montana

Mid-flagged peers for Ravalli County

Cross-state counties nearest Ravalli County on flagged-system share (93.0%) and cumulative violation count (9,816). 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.