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Community Water System · PWS MT0000231

Grass Range Town Of

Grass Range, Montana 59032 - drinking water served from groundwater sources to 102 people, tracked in EPA SDWIS and UCMR5.

102
People served
198
EPA violations
0
Health-based
Untested
UCMR5 result

The verdict

EPA records 198 drinking-water violations at Grass Range Town Of - above the Montana per-system average.

198
Total EPA violations on record
0%
Health-based (MCL / treatment failure)
102
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Grass Range Town Of

Grass Range Town Of is a local-owned community water system that delivers drinking water to 102 residents in Grass Range, Montana (Fergus County) through 88 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 198 total violations for this system , of which 0 (0%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 181 monitoring and reporting violations are on file. The most recent violation on record dates to 2023.

The most frequently cited contaminant at this system is Consumer Confidence Rule, recorded in 15 violations (Other). 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%).

Grass Range Town Of's 198 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
102
Total Violations
198
Health-Based Violations
0
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
88
County
Fergus
School/Daycare
No
MCL Violations
0
Monitoring Violations
181
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Consumer Confidence Rule Other 15 2023
Di(2-ethylhexyl) phthalate MR 12 2004
Nitrate-Nitrite MR 10 2023
Coliform (TCR) MR 10 2001
Lead and Copper Rule MR 9 2023
1,2,4-Trichlorobenzene MR 6 2011
Xylenes, Total MR 6 2011
DICHLOROMETHANE MR 6 2011
o-Dichlorobenzene MR 6 2011
Vinyl chloride MR 6 2011
trans-1,2-Dichloroethylene MR 6 2011
Trichloroethylene MR 6 2011
CHLOROBENZENE MR 6 2011
Benzene MR 6 2011
Toluene MR 6 2011
Styrene MR 6 2011
p-Dichlorobenzene MR 6 2011
1,2-Dichloroethane MR 6 2011
1,1,1-Trichloroethane MR 6 2011
1,2-Dichloropropane MR 6 2011
1,1,2-Trichloroethane MR 6 2011
Ethylbenzene MR 6 2011
Carbon tetrachloride MR 6 2011
Tetrachloroethylene MR 6 2011
cis-1,2-Dichloroethylene MR 6 2011
1,1-Dichloroethylene MR 6 2011
Asbestos MR 3 2011
Total Haloacetic Acids (HAA5) MR 3 2023
TTHM MR 3 2023
E. COLI MR 3 2010

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 Grass Range 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 MT0000231 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
2023 Consumer Confidence Rule Other 15 SDWIS / MT0000231 / 7000
2023 Nitrate-Nitrite MR 10 SDWIS / MT0000231 / 1038
2023 Lead and Copper Rule MR 9 SDWIS / MT0000231 / 5000
2023 Total Haloacetic Acids (HAA5) MR 3 SDWIS / MT0000231 / 2456
2023 TTHM MR 3 SDWIS / MT0000231 / 2950
2011 1,2,4-Trichlorobenzene MR 6 SDWIS / MT0000231 / 2378
2011 Xylenes, Total MR 6 SDWIS / MT0000231 / 2955
2011 DICHLOROMETHANE MR 6 SDWIS / MT0000231 / 2964
2011 o-Dichlorobenzene MR 6 SDWIS / MT0000231 / 2968
2011 Vinyl chloride MR 6 SDWIS / MT0000231 / 2976
2011 trans-1,2-Dichloroethylene MR 6 SDWIS / MT0000231 / 2979
2011 Trichloroethylene MR 6 SDWIS / MT0000231 / 2984
2011 CHLOROBENZENE MR 6 SDWIS / MT0000231 / 2989
2011 Benzene MR 6 SDWIS / MT0000231 / 2990
2011 Toluene MR 6 SDWIS / MT0000231 / 2991

How Grass Range Town Of Compares

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

Metric Grass Range Town Of Montana avg Federal benchmark
Total violations 198 131.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 0 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 102 492 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 Grass Range Town Of water safe to drink? ▼
Grass Range Town Of (PWS ID: MT0000231) has 198 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 102 people using Groundwater sources.
How many people does Grass Range Town Of serve? ▼
Grass Range Town Of serves 102 people in Grass Range, Montana. It is a Local-owned system using Groundwater water sources with 88 service connections.
What type of violations does Grass Range Town Of have? ▼
Grass Range Town Of has 198 total violations: 0 health-based violations (MCL exceedances or treatment failures), 181 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Grass Range Town Of water? ▼
No PFAS testing data is available for Grass Range Town Of under the EPA's UCMR5 monitoring program.
What water source does Grass Range Town Of use? ▼
Grass Range 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.

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.