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States → EPA Region 8 — Tribal Water Systems

Community Water System · PWS 084690440

Fort Thompson Water System

Fort Thompson, EPA Region 8 — Tribal Water Systems 57339 - drinking water served from surface water sources to 1,357 people, tracked in EPA SDWIS and UCMR5.

1,357
People served
224
EPA violations
39
Health-based
Untested
UCMR5 result

The verdict

EPA records 224 drinking-water violations at Fort Thompson Water System, 17% of them health-based.

224
Total EPA violations on record
17%
Health-based (MCL / treatment failure)
1,357
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Fort Thompson Water System

Fort Thompson Water System is a native american-owned community water system that delivers drinking water to 1,357 residents in Fort Thompson, EPA Region 8 — Tribal Water Systems through 302 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 224 total violations for this system , of which 39 (17%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 180 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 31 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

EPA Region 8 — Tribal Water Systems has thousands of regulated public water systems tracked by EPA under the Safe Drinking Water Act.

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
1,357
Total Violations
224
Health-Based Violations
39
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Native American
Connections
302
School/Daycare
No
MCL Violations
37
Monitoring Violations
180
Treatment Tech Violations
2

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 31 2012
TTHM MCL 30 2012
TTHM MR 16 2024
Total Haloacetic Acids (HAA5) MR 16 2024
Fluoride MR 6 2022
Total Haloacetic Acids (HAA5) MCL 5 2004
Lead and Copper Rule MR 4 2003
Barium MR 3 2005
Cadmium MR 3 2005
Chromium MR 3 2005
Selenium MR 3 2005
CYANIDE MR 3 2005
Nitrate MR 3 1994
Mercury MR 3 2005
Arsenic MR 3 2005
1,2,4-Trichlorobenzene MR 2 2010
cis-1,2-Dichloroethylene MR 2 2010
DICHLOROMETHANE MR 2 2010
p-Dichlorobenzene MR 2 2010
Vinyl chloride MR 2 2010
1,1-Dichloroethylene MR 2 2010
trans-1,2-Dichloroethylene MR 2 2010
1,1,1-Trichloroethane MR 2 2010
1,2-Dichloropropane MR 2 2010
Trichloroethylene MR 2 2010
Tetrachloroethylene MR 2 2010
CHLOROBENZENE MR 2 2010
Toluene MR 2 2010
Styrene MR 2 2010
Chlorine MR 2 2012

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 Fort Thompson Water System.

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 084690440 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

EPA Region 8 — Tribal Water Systems Drinking Water Authority

EPA Region 8 — Tribal Water Systems'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 08 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 TTHM MR 16 SDWIS / 084690440 / 2950
2024 Total Haloacetic Acids (HAA5) MR 16 SDWIS / 084690440 / 2456
2022 Fluoride MR 6 SDWIS / 084690440 / 1025
2022 Long Term 2 Enhanced Surface Water Treatment Rule TT 1 SDWIS / 084690440 / 0800
2021 Revised Total Coliform Rule MON 1 SDWIS / 084690440 / 8000
2013 Coliform (TCR) MCL 2 SDWIS / 084690440 / 3100
2012 Coliform (TCR) MR 31 SDWIS / 084690440 / 3100
2012 TTHM MCL 30 SDWIS / 084690440 / 2950
2012 Chlorine MR 2 SDWIS / 084690440 / 0999
2010 1,2,4-Trichlorobenzene MR 2 SDWIS / 084690440 / 2378
2010 cis-1,2-Dichloroethylene MR 2 SDWIS / 084690440 / 2380
2010 DICHLOROMETHANE MR 2 SDWIS / 084690440 / 2964
2010 p-Dichlorobenzene MR 2 SDWIS / 084690440 / 2969
2010 Vinyl chloride MR 2 SDWIS / 084690440 / 2976
2010 1,1-Dichloroethylene MR 2 SDWIS / 084690440 / 2977

How Fort Thompson Water System Compares

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

Metric Fort Thompson Water System EPA Region 8 — Tribal Water Systems avg Federal benchmark
Total violations 224 - SDWA compliance, any non-zero count is a recorded breach
Health-based violations 39 - Indicates a contaminant exceeded a federal MCL
PFAS detection None - EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 1,357 - Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across all regulated public water systems in EPA Region 8 — Tribal Water Systems.

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 Fort Thompson Water System water safe to drink? ▼
Fort Thompson Water System (PWS ID: 084690440) has 224 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 1,357 people using Surface Water sources.
How many people does Fort Thompson Water System serve? ▼
Fort Thompson Water System serves 1,357 people in Fort Thompson, EPA Region 8 — Tribal Water Systems. It is a Native American-owned system using Surface Water water sources with 302 service connections.
What type of violations does Fort Thompson Water System have? ▼
Fort Thompson Water System has 224 total violations: 39 health-based violations (MCL exceedances or treatment failures), 180 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Fort Thompson Water System water? ▼
No PFAS testing data is available for Fort Thompson Water System under the EPA's UCMR5 monitoring program.
What water source does Fort Thompson Water System use? ▼
Fort Thompson Water System uses Surface Water 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.