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Community Water System · PWS NN0400207

Coal Mine Mesa NTUA

Fort Defiance, Navajo Nation 86504-0170 - drinking water served from groundwater sources to 393 people, tracked in EPA SDWIS and UCMR5.

393
People served
124
EPA violations
0
Health-based
Untested
UCMR5 result

The verdict

EPA records 124 drinking-water violations at Coal Mine Mesa NTUA - below the Navajo Nation per-system average.

124
Total EPA violations on record
0%
Health-based (MCL / treatment failure)
393
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Coal Mine Mesa NTUA

Coal Mine Mesa NTUA is a native american-owned community water system that delivers drinking water to 393 residents in Fort Defiance, Navajo Nation through 115 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 124 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 121 monitoring and reporting violations are on file. The most recent violation on record dates to 2020.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 9 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 Navajo Nation, EPA tracks 170 public water systems serving 167,275 people, with 29,535 cumulative violations and 1,366 health-based violations on record. About 100% of systems in the state carry at least one violation, and state-wide the average per system is 173.7 violations. Statewide, 13 of 13 UCMR5-tested systems have reported PFAS detections (100%).

Coal Mine Mesa NTUA's 124 violations sit below the Navajo Nation 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
393
Total Violations
124
Health-Based Violations
0
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Native American
Connections
115
School/Daycare
No
MCL Violations
0
Monitoring Violations
121
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 9 2002
1,2,4-Trichlorobenzene MR 3 2008
cis-1,2-Dichloroethylene MR 3 2008
DICHLOROMETHANE MR 3 2008
o-Dichlorobenzene MR 3 2008
p-Dichlorobenzene MR 3 2008
Vinyl chloride MR 3 2008
1,1-Dichloroethylene MR 3 2008
trans-1,2-Dichloroethylene MR 3 2008
1,1,1-Trichloroethane MR 3 2008
Carbon tetrachloride MR 3 2008
1,2-Dichloropropane MR 3 2008
Trichloroethylene MR 3 2008
1,1,2-Trichloroethane MR 3 2008
Tetrachloroethylene MR 3 2008
CHLOROBENZENE MR 3 2008
Benzene MR 3 2008
Toluene MR 3 2008
Ethylbenzene MR 3 2008
Styrene MR 3 2008
Total Haloacetic Acids (HAA5) MR 3 2020
Xylenes, Total MR 3 2008
1,2-Dichloroethane MR 3 2008
TTHM MR 3 2020
Diquat MR 2 2004
Endothall MR 2 2004
2,3,7,8-TCDD MR 2 2004
1,2-DIBROMO-3-CHLOROPROPANE MR 2 2008
ETHYLENE DIBROMIDE MR 2 2008
Glyphosate MR 2 2004

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 Coal Mine Mesa NTUA.

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 NN0400207 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Navajo Nation Drinking Water Authority

Navajo Nation'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 NN 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
2020 Total Haloacetic Acids (HAA5) MR 3 SDWIS / NN0400207 / 2456
2020 TTHM MR 3 SDWIS / NN0400207 / 2950
2011 Cadmium MR 1 SDWIS / NN0400207 / 1015
2011 Chromium MR 1 SDWIS / NN0400207 / 1020
2011 Selenium MR 1 SDWIS / NN0400207 / 1045
2011 Antimony, Total MR 1 SDWIS / NN0400207 / 1074
2011 Thallium, Total MR 1 SDWIS / NN0400207 / 1085
2011 Arsenic MR 1 SDWIS / NN0400207 / 1005
2011 Barium MR 1 SDWIS / NN0400207 / 1010
2011 Beryllium, Total MR 1 SDWIS / NN0400207 / 1075
2011 Mercury MR 1 SDWIS / NN0400207 / 1035
2008 1,2,4-Trichlorobenzene MR 3 SDWIS / NN0400207 / 2378
2008 cis-1,2-Dichloroethylene MR 3 SDWIS / NN0400207 / 2380
2008 DICHLOROMETHANE MR 3 SDWIS / NN0400207 / 2964
2008 o-Dichlorobenzene MR 3 SDWIS / NN0400207 / 2968

How Coal Mine Mesa NTUA Compares

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

Metric Coal Mine Mesa NTUA Navajo Nation avg Federal benchmark
Total violations 124 173.7 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 0 8 Indicates a contaminant exceeded a federal MCL
PFAS detection None 100% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 393 984 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 170 regulated public water systems in Navajo Nation.

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 Coal Mine Mesa NTUA water safe to drink? ▼
Coal Mine Mesa NTUA (PWS ID: NN0400207) has 124 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 393 people using Groundwater sources.
How many people does Coal Mine Mesa NTUA serve? ▼
Coal Mine Mesa NTUA serves 393 people in Fort Defiance, Navajo Nation. It is a Native American-owned system using Groundwater water sources with 115 service connections.
What type of violations does Coal Mine Mesa NTUA have? ▼
Coal Mine Mesa NTUA has 124 total violations: 0 health-based violations (MCL exceedances or treatment failures), 121 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Coal Mine Mesa NTUA water? ▼
No PFAS testing data is available for Coal Mine Mesa NTUA under the EPA's UCMR5 monitoring program.
What water source does Coal Mine Mesa NTUA use? ▼
Coal Mine Mesa NTUA 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.