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Community Water System · PWS MT0000587

Oilmont County Water District

Sunburst, Montana 59482 - drinking water served from groundwater sources to 300 people, tracked in EPA SDWIS and UCMR5.

300
People served
1,107
EPA violations
174
Health-based
Untested
UCMR5 result

The verdict

EPA records 1,107 drinking-water violations at Oilmont County Water District, 16% of them health-based - above the Montana per-system average.

1,107
Total EPA violations on record
16%
Health-based (MCL / treatment failure)
300
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Oilmont County Water District

Oilmont County Water District is a local-owned community water system that delivers drinking water to 300 residents in Sunburst, Montana (Toole County) through 76 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 1,107 total violations for this system , of which 174 (16%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 923 monitoring and reporting violations are on file. The most recent violation on record dates to 2024.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 135 violations (MCL, 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%).

Oilmont County Water District's 1,107 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
300
Total Violations
1,107
Health-Based Violations
174
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
76
County
Toole
School/Daycare
No
MCL Violations
135
Monitoring Violations
923
Treatment Tech Violations
39

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MCL 135 2015
Groundwater Rule TT 39 2021
1,2,4-Trichlorobenzene MR 39 2020
cis-1,2-Dichloroethylene MR 39 2020
Xylenes, Total MR 39 2020
DICHLOROMETHANE MR 39 2020
Vinyl chloride MR 39 2020
trans-1,2-Dichloroethylene MR 39 2020
1,2-Dichloroethane MR 39 2020
1,1,1-Trichloroethane MR 39 2020
Carbon tetrachloride MR 39 2020
1,2-Dichloropropane MR 39 2020
Trichloroethylene MR 39 2020
1,1,2-Trichloroethane MR 39 2020
Toluene MR 39 2020
Styrene MR 39 2020
p-Dichlorobenzene MR 39 2020
1,1-Dichloroethylene MR 39 2020
Tetrachloroethylene MR 39 2020
CHLOROBENZENE MR 39 2020
Ethylbenzene MR 39 2020
o-Dichlorobenzene MR 39 2020
Benzene MR 39 2020
Coliform (TCR) MR 31 2015
2,4,5-TP MR 18 2020
Lead and Copper Rule MR 16 2020
Groundwater Rule MR 16 2022
Consumer Confidence Rule Other 8 2024
E. COLI MR 7 2012
TTHM MR 6 2018

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 Oilmont County Water District.

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 MT0000587 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
2024 Consumer Confidence Rule Other 8 SDWIS / MT0000587 / 7000
2022 Groundwater Rule MR 16 SDWIS / MT0000587 / 0700
2021 Groundwater Rule TT 39 SDWIS / MT0000587 / 0700
2020 1,2,4-Trichlorobenzene MR 39 SDWIS / MT0000587 / 2378
2020 cis-1,2-Dichloroethylene MR 39 SDWIS / MT0000587 / 2380
2020 Xylenes, Total MR 39 SDWIS / MT0000587 / 2955
2020 DICHLOROMETHANE MR 39 SDWIS / MT0000587 / 2964
2020 Vinyl chloride MR 39 SDWIS / MT0000587 / 2976
2020 trans-1,2-Dichloroethylene MR 39 SDWIS / MT0000587 / 2979
2020 1,2-Dichloroethane MR 39 SDWIS / MT0000587 / 2980
2020 1,1,1-Trichloroethane MR 39 SDWIS / MT0000587 / 2981
2020 Carbon tetrachloride MR 39 SDWIS / MT0000587 / 2982
2020 1,2-Dichloropropane MR 39 SDWIS / MT0000587 / 2983
2020 Trichloroethylene MR 39 SDWIS / MT0000587 / 2984
2020 1,1,2-Trichloroethane MR 39 SDWIS / MT0000587 / 2985

How Oilmont County Water District Compares

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

Metric Oilmont County Water District Montana avg Federal benchmark
Total violations 1,107 131.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 174 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 300 492 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 Oilmont County Water District water safe to drink? ▼
Oilmont County Water District (PWS ID: MT0000587) has 1107 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 300 people using Groundwater sources.
How many people does Oilmont County Water District serve? ▼
Oilmont County Water District serves 300 people in Sunburst, Montana. It is a Local-owned system using Groundwater water sources with 76 service connections.
What type of violations does Oilmont County Water District have? ▼
Oilmont County Water District has 1,107 total violations: 174 health-based violations (MCL exceedances or treatment failures), 923 monitoring/reporting violations, and 39 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Oilmont County Water District water? ▼
No PFAS testing data is available for Oilmont County Water District under the EPA's UCMR5 monitoring program.
What water source does Oilmont County Water District use? ▼
Oilmont County Water District 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.

Read our methodology - 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 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.