PlainWater

Community Water System · PWS MT0001740

St Ignatius Town Of

St Ignatius, Montana 59865 - drinking water served from groundwater sources to 700 people, tracked in EPA SDWIS and UCMR5.

700
People served
168
EPA violations
33
Health-based
Untested
UCMR5 result

The verdict

EPA records 168 drinking-water violations at St Ignatius Town Of, 20% of them health-based - above the Montana per-system average.

168
Total EPA violations on record
20%
Health-based (MCL / treatment failure)
700
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: St Ignatius Town Of

St Ignatius Town Of is a local-owned community water system that delivers drinking water to 700 residents in St Ignatius, Montana (Lake County) through 291 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 168 total violations for this system , of which 33 (20%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 129 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.

The most frequently cited contaminant at this system is Groundwater Rule, recorded in 17 violations (TT, health-based). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across Montana, EPA tracks 2,263 public water systems serving 1,112,267 people, with 297,270 cumulative violations and 25,922 health-based violations on record. About 95% of systems in the state carry at least one violation, and state-wide the average per system is 131.4 violations. Statewide, 28 of 45 UCMR5-tested systems have reported PFAS detections (62.2%).

St Ignatius Town Of's 168 violations sit above the Montana average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
700
Total Violations
168
Health-Based Violations
33
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
291
County
Lake
School/Daycare
No
MCL Violations
16
Monitoring Violations
129
Treatment Tech Violations
17

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Groundwater Rule TT 17 2016
Coliform (TCR) MCL 16 2010
Coliform (TCR) MR 9 2011
Lead and Copper Rule MR 8 2022
Groundwater Rule MR 7 2025
Consumer Confidence Rule Other 6 2012
TTHM MR 6 2019
Total Haloacetic Acids (HAA5) MR 6 2019
Gross Alpha, Excl. Radon and U MR 5 2016
Methoxychlor MR 3 2016
Toxaphene MR 3 2016
OXAMYL MR 3 2016
Simazine MR 3 2016
Di(2-ethylhexyl) phthalate MR 3 2016
Picloram MR 3 2016
Dinoseb MR 3 2016
Aldicarb sulfone MR 3 2016
Carbofuran MR 3 2016
Aldicarb MR 3 2016
LASSO MR 3 2016
Heptachlor MR 3 2016
2,4-D MR 3 2016
2,4,5-TP MR 3 2016
HEXACHLOROBENZENE MR 3 2016
Pentachlorophenol MR 3 2016
Chlordane MR 3 2016
Combined Radium (-226 and -228) MR 3 2016
E. COLI MR 3 2024
Heptachlor epoxide MR 3 2016
Di(2-ethylhexyl) adipate MR 3 2016

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for St Ignatius Town Of.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID MT0001740 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Montana Drinking Water Authority

Montana's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.

Find MT regulator via EPA SDWIS

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2025 Groundwater Rule MR 7 SDWIS / MT0001740 / 0700
2024 E. COLI MR 3 SDWIS / MT0001740 / 3014
2024 Nitrate-Nitrite MR 3 SDWIS / MT0001740 / 1038
2022 Lead and Copper Rule MR 8 SDWIS / MT0001740 / 5000
2019 TTHM MR 6 SDWIS / MT0001740 / 2950
2019 Total Haloacetic Acids (HAA5) MR 6 SDWIS / MT0001740 / 2456
2016 Groundwater Rule TT 17 SDWIS / MT0001740 / 0700
2016 Gross Alpha, Excl. Radon and U MR 5 SDWIS / MT0001740 / 4000
2016 Methoxychlor MR 3 SDWIS / MT0001740 / 2015
2016 Toxaphene MR 3 SDWIS / MT0001740 / 2020
2016 OXAMYL MR 3 SDWIS / MT0001740 / 2036
2016 Simazine MR 3 SDWIS / MT0001740 / 2037
2016 Di(2-ethylhexyl) phthalate MR 3 SDWIS / MT0001740 / 2039
2016 Picloram MR 3 SDWIS / MT0001740 / 2040
2016 Dinoseb MR 3 SDWIS / MT0001740 / 2041

How St Ignatius Town Of Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric St Ignatius Town Of Montana avg Federal benchmark
Total violations 168 131.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 33 11.5 Indicates a contaminant exceeded a federal MCL
PFAS detection None 62.2% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 700 492 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 2,263 regulated public water systems in Montana.

Federal MCL reference, Safe Drinking Water Act thresholds
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is St Ignatius Town Of water safe to drink?
St Ignatius Town Of (PWS ID: MT0001740) has 168 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 700 people using Groundwater sources.
How many people does St Ignatius Town Of serve?
St Ignatius Town Of serves 700 people in St Ignatius, Montana. It is a Local-owned system using Groundwater water sources with 291 service connections.
What type of violations does St Ignatius Town Of have?
St Ignatius Town Of has 168 total violations: 33 health-based violations (MCL exceedances or treatment failures), 129 monitoring/reporting violations, and 17 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in St Ignatius Town Of water?
No PFAS testing data is available for St Ignatius Town Of under the EPA's UCMR5 monitoring program.
What water source does St Ignatius Town Of use?
St Ignatius Town Of uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from?
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.
Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from 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.