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Non-Transient Non-Community Water System · PWS MT0000191

Little Bighorn Battlefield NM

Crow Agency, Montana 59022 - drinking water served from groundwater sources to 2,020 people, tracked in EPA SDWIS and UCMR5.

2,020
People served
42
EPA violations
0
Health-based
Untested
UCMR5 result

The verdict

EPA records 42 drinking-water violations at Little Bighorn Battlefield NM - below the Montana per-system average.

42
Total EPA violations on record
0%
Health-based (MCL / treatment failure)
2,020
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Little Bighorn Battlefield NM

Little Bighorn Battlefield NM is a federal-owned non-transient non-community water system that delivers drinking water to 2,020 residents in Crow Agency, Montana (Big Horn County) through 11 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 42 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 42 monitoring and reporting violations are on file. The most recent violation on record dates to 2022.

The most frequently cited contaminant at this system is Lead and Copper Rule, recorded in 12 violations (MR). 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%).

Little Bighorn Battlefield NM's 42 violations sit below 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
2,020
Total Violations
42
Health-Based Violations
0
Water Source
Groundwater

System Details

System Type
Non-Transient Non-Community
Owner Type
Federal
Connections
11
County
Big Horn
School/Daycare
No
MCL Violations
0
Monitoring Violations
42
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Lead and Copper Rule MR 12 2020
Nitrate-Nitrite MR 8 2022
Coliform (TCR) MR 7 2011
TTHM MR 6 2021
Total Haloacetic Acids (HAA5) MR 6 2021
Asbestos MR 2 2011
Fluoride MR 1 1996

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 Little Bighorn Battlefield NM.

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 MT0000191 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
2022 Nitrate-Nitrite MR 8 SDWIS / MT0000191 / 1038
2021 TTHM MR 6 SDWIS / MT0000191 / 2950
2021 Total Haloacetic Acids (HAA5) MR 6 SDWIS / MT0000191 / 2456
2020 Lead and Copper Rule MR 12 SDWIS / MT0000191 / 5000
2011 Coliform (TCR) MR 7 SDWIS / MT0000191 / 3100
2011 Asbestos MR 2 SDWIS / MT0000191 / 1094
1996 Fluoride MR 1 SDWIS / MT0000191 / 1025

How Little Bighorn Battlefield NM Compares

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

Metric Little Bighorn Battlefield NM Montana avg Federal benchmark
Total violations 42 131.4 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 2,020 492 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 Little Bighorn Battlefield NM water safe to drink? ▼
Little Bighorn Battlefield NM (PWS ID: MT0000191) has 42 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 2,020 people using Groundwater sources.
How many people does Little Bighorn Battlefield NM serve? ▼
Little Bighorn Battlefield NM serves 2,020 people in Crow Agency, Montana. It is a Federal-owned system using Groundwater water sources with 11 service connections.
What type of violations does Little Bighorn Battlefield NM have? ▼
Little Bighorn Battlefield NM has 42 total violations: 0 health-based violations (MCL exceedances or treatment failures), 42 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Little Bighorn Battlefield NM water? ▼
No PFAS testing data is available for Little Bighorn Battlefield NM under the EPA's UCMR5 monitoring program.
What water source does Little Bighorn Battlefield NM use? ▼
Little Bighorn Battlefield NM uses Groundwater as its primary water source. It is classified as a Non-Transient Non-Community Water System, serving the same people for at least 6 months per year.
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.