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States → Navajo Nation

Community Water System · PWS NN4903071

Todahaidekani NTUA

Ft Defiance, Navajo Nation 86504 - drinking water served from surface water sources to 301 people, tracked in EPA SDWIS and UCMR5.

301
People served
140
EPA violations
31
Health-based
Untested
UCMR5 result

The verdict

EPA records 140 drinking-water violations at Todahaidekani NTUA, 22% of them health-based - below the Navajo Nation per-system average.

140
Total EPA violations on record
22%
Health-based (MCL / treatment failure)
301
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Todahaidekani NTUA

Todahaidekani NTUA is a native american-owned community water system that delivers drinking water to 301 residents in Ft Defiance, Navajo Nation through 88 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 140 total violations for this system , of which 31 (22%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 82 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 Arsenic, recorded in 31 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 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%).

Todahaidekani NTUA's 140 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
301
Total Violations
140
Health-Based Violations
31
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Native American
Connections
88
School/Daycare
No
MCL Violations
31
Monitoring Violations
82
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Arsenic MCL 31 2020
Public Notice Other 8 2020
Coliform (TCR) MR 6 2012
Arsenic MR 3 2022
Stage 2 Disinfectants and Disinfection Byproducts Rule MR 3 2013
Glyphosate MR 2 2008
Gross Alpha, Excl. Radon and U MR 2 2005
Revised Total Coliform Rule Other 2 2016
Endothall MR 2 2008
2,3,7,8-TCDD MR 2 2008
Total Polychlorinated Biphenyls (PCB) MR 2 2008
Diquat MR 2 2008
Fluoride MR 1 2008
Nitrite MR 1 2010
Selenium MR 1 2008
Antimony, Total MR 1 2008
Beryllium, Total MR 1 2008
Endrin MR 1 2008
Dalapon MR 1 2008
Di(2-ethylhexyl) adipate MR 1 2008
Simazine MR 1 2008
Di(2-ethylhexyl) phthalate MR 1 2008
Picloram MR 1 2008
Hexachlorocyclopentadiene MR 1 2008
Atrazine MR 1 2008
LASSO MR 1 2008
Heptachlor epoxide MR 1 2008
2,4-D MR 1 2008
HEXACHLOROBENZENE MR 1 2008
Pentachlorophenol MR 1 2008

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 Todahaidekani 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 NN4903071 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
2022 Arsenic MR 3 SDWIS / NN4903071 / 1005
2020 Arsenic MCL 31 SDWIS / NN4903071 / 1005
2020 Public Notice Other 8 SDWIS / NN4903071 / 7500
2016 Revised Total Coliform Rule Other 2 SDWIS / NN4903071 / 8000
2013 Stage 2 Disinfectants and Disinfection Byproducts Rule MR 3 SDWIS / NN4903071 / 0600
2012 Coliform (TCR) MR 6 SDWIS / NN4903071 / 3100
2010 Nitrite MR 1 SDWIS / NN4903071 / 1041
2008 Glyphosate MR 2 SDWIS / NN4903071 / 2034
2008 Endothall MR 2 SDWIS / NN4903071 / 2033
2008 2,3,7,8-TCDD MR 2 SDWIS / NN4903071 / 2063
2008 Total Polychlorinated Biphenyls (PCB) MR 2 SDWIS / NN4903071 / 2383
2008 Diquat MR 2 SDWIS / NN4903071 / 2032
2008 Fluoride MR 1 SDWIS / NN4903071 / 1025
2008 Selenium MR 1 SDWIS / NN4903071 / 1045
2008 Antimony, Total MR 1 SDWIS / NN4903071 / 1074

How Todahaidekani NTUA Compares

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

Metric Todahaidekani NTUA Navajo Nation avg Federal benchmark
Total violations 140 173.7 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 31 8 Indicates a contaminant exceeded a federal MCL
PFAS detection None 100% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 301 984 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 Todahaidekani NTUA water safe to drink? ▼
Todahaidekani NTUA (PWS ID: NN4903071) has 140 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 301 people using Surface Water sources.
How many people does Todahaidekani NTUA serve? ▼
Todahaidekani NTUA serves 301 people in Ft Defiance, Navajo Nation. It is a Native American-owned system using Surface Water water sources with 88 service connections.
What type of violations does Todahaidekani NTUA have? ▼
Todahaidekani NTUA has 140 total violations: 31 health-based violations (MCL exceedances or treatment failures), 82 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Todahaidekani NTUA water? ▼
No PFAS testing data is available for Todahaidekani NTUA under the EPA's UCMR5 monitoring program.
What water source does Todahaidekani NTUA use? ▼
Todahaidekani NTUA 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.