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Dilkon-Indian Wells-Greasewood-White Cone NTUA

PWS ID: NN0400342 · Fort Defiance, Navajo Nation 86504

Dilkon-Indian Wells-Greasewood-White Cone NTUA serves 4,986 people in Fort Defiance, Navajo Nation using Groundwater water sources. It has 223 recorded EPA violations, including 107 health-based violations. PFAS "forever chemicals" were detected in UCMR5 testing (1 compound found).

Water Quality Snapshot: Dilkon-Indian Wells-Greasewood-White Cone NTUA

Dilkon-Indian Wells-Greasewood-White Cone NTUA is a native american-owned community water system that delivers drinking water to 4,986 residents in Fort Defiance, Navajo Nation through 1,458 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 223 total violations for this system , of which 107 (48%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 59 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 TTHM, recorded in 71 violations (MCL, health-based). Under EPA's UCMR5 PFAS monitoring program, 1 PFAS compound was detected in samples collected from this system, with a maximum reported concentration of 92.4 ppt. PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

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. Dilkon-Indian Wells-Greasewood-White Cone NTUA's 223 violations sit above the Navajo Nation average. Statewide, 13 of 13 UCMR5-tested systems have reported PFAS detections (100%). All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

PFAS Detected

1 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
4,986
Total Violations
223
Health-Based Violations
107
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Native American
Connections
1,458
School/Daycare
No
MCL Violations
105
Monitoring Violations
59
Treatment Tech Violations
2

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
TTHM MCL 71 2021
Coliform (TCR) MCL 34 2015
Public Notice Other 14 2022
Total Haloacetic Acids (HAA5) MR 10 2015
TTHM MR 10 2015
Coliform (TCR) MR 9 2012
Revised Total Coliform Rule MON 4 2022
Revised Total Coliform Rule TT 2 2016
1,2,4-Trichlorobenzene MR 1 2005
cis-1,2-Dichloroethylene MR 1 2005
DICHLOROMETHANE MR 1 2005
o-Dichlorobenzene MR 1 2005
trans-1,2-Dichloroethylene MR 1 2005
1,2-Dichloroethane MR 1 2005
1,2-Dichloropropane MR 1 2005
Trichloroethylene MR 1 2005
CHLOROBENZENE MR 1 2005
Ethylbenzene MR 1 2005
Styrene MR 1 2005
Combined Radium (-226 and -228) MR 1 2005
Lead and Copper Rule MR 1 2004
Revised Total Coliform Rule Other 1 2016
Combined Uranium MR 1 2005
Xylenes, Total MR 1 2005
Tetrachloroethylene MR 1 2005
1,1-Dichloroethylene MR 1 2005
Toluene MR 1 2005
Gross Alpha, Excl. Radon and U MR 1 2005
p-Dichlorobenzene MR 1 2005
E. COLI MR 1 2013

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 3 of 90 samples detected PFAS.

Contaminant Date Result MRL Status
PFDoA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFHxA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFUnA 6/16/2025 <0.002 µg/L 0.002 µg/L Not Detected
11Cl-PF3OUdS 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
9Cl-PF3ONS 6/16/2025 <0.002 µg/L 0.002 µg/L Not Detected
HFPO-DA 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFDA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFTrDA 6/16/2025 <0.007 µg/L 0.007 µg/L Not Detected
ADONA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFOA 6/16/2025 <0.004 µg/L 0.004 µg/L Not Detected
PFOS 6/16/2025 <0.004 µg/L 0.004 µg/L Not Detected
PFNA 6/16/2025 <0.004 µg/L 0.004 µg/L Not Detected
PFHxS 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
lithium 6/16/2025 78.9000 µg/L 9 µg/L Detected
NEtFOSAA 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFTA 6/16/2025 <0.008 µg/L 0.008 µg/L Not Detected
PFBA 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFBS 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 6/16/2025 <0.02 µg/L 0.02 µg/L Not Detected
6:2 FTS 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
NMeFOSAA 6/16/2025 <0.006 µg/L 0.006 µg/L Not Detected
PFPeS 6/16/2025 <0.004 µg/L 0.004 µg/L Not Detected
PFEESA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFMPA 6/16/2025 <0.004 µg/L 0.004 µg/L Not Detected
8:2 FTS 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFHpS 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
ADONA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
8:2 FTS 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFUnA 6/16/2025 <0.002 µg/L 0.002 µg/L Not Detected
PFMBA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFMPA 6/16/2025 <0.004 µg/L 0.004 µg/L Not Detected
4:2 FTS 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
6:2 FTS 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFBA 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFHxA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
HFPO-DA 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFEESA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
9Cl-PF3ONS 6/16/2025 <0.002 µg/L 0.002 µg/L Not Detected
11Cl-PF3OUdS 6/16/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFHpS 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFPeS 6/16/2025 <0.004 µg/L 0.004 µg/L Not Detected
lithium 6/16/2025 92.4000 µg/L 9 µg/L Detected
PFTA 6/16/2025 <0.008 µg/L 0.008 µg/L Not Detected
PFTrDA 6/16/2025 <0.007 µg/L 0.007 µg/L Not Detected
PFDoA 6/16/2025 <0.003 µg/L 0.003 µg/L Not Detected

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 Dilkon-Indian Wells-Greasewood-White Cone 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 NN0400342 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 Public Notice Other 14 SDWIS / NN0400342 / 7500
2022 Revised Total Coliform Rule MON 4 SDWIS / NN0400342 / 8000
2021 TTHM MCL 71 SDWIS / NN0400342 / 2950
2016 Revised Total Coliform Rule TT 2 SDWIS / NN0400342 / 8000
2016 Revised Total Coliform Rule Other 1 SDWIS / NN0400342 / 8000
2015 Coliform (TCR) MCL 34 SDWIS / NN0400342 / 3100
2015 Total Haloacetic Acids (HAA5) MR 10 SDWIS / NN0400342 / 2456
2015 TTHM MR 10 SDWIS / NN0400342 / 2950
2013 E. COLI MR 1 SDWIS / NN0400342 / 3014
2012 Coliform (TCR) MR 9 SDWIS / NN0400342 / 3100
2005 1,2,4-Trichlorobenzene MR 1 SDWIS / NN0400342 / 2378
2005 cis-1,2-Dichloroethylene MR 1 SDWIS / NN0400342 / 2380
2005 DICHLOROMETHANE MR 1 SDWIS / NN0400342 / 2964
2005 o-Dichlorobenzene MR 1 SDWIS / NN0400342 / 2968
2005 trans-1,2-Dichloroethylene MR 1 SDWIS / NN0400342 / 2979

How Dilkon-Indian Wells-Greasewood-White Cone NTUA Compares

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

Metric Dilkon-Indian Wells-Greasewood-White Cone NTUA Navajo Nation avg Federal benchmark
Total violations 223 173.7 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 107 8 Indicates a contaminant exceeded a federal MCL
PFAS detection 1 compound 100% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 4,986 984 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
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Dilkon-Indian Wells-Greasewood-White Cone NTUA water safe to drink? ▼
Dilkon-Indian Wells-Greasewood-White Cone NTUA (PWS ID: NN0400342) has 223 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 1 PFAS compound found. This system serves 4,986 people using Groundwater sources.
How many people does Dilkon-Indian Wells-Greasewood-White Cone NTUA serve? ▼
Dilkon-Indian Wells-Greasewood-White Cone NTUA serves 4,986 people in Fort Defiance, Navajo Nation. It is a Native American-owned system using Groundwater water sources with 1,458 service connections.
What type of violations does Dilkon-Indian Wells-Greasewood-White Cone NTUA have? ▼
Dilkon-Indian Wells-Greasewood-White Cone NTUA has 223 total violations: 107 health-based violations (MCL exceedances or treatment failures), 59 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Dilkon-Indian Wells-Greasewood-White Cone NTUA water? ▼
Yes. UCMR5 testing detected 1 PFAS compound in Dilkon-Indian Wells-Greasewood-White Cone NTUA's water supply: lithium. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does Dilkon-Indian Wells-Greasewood-White Cone NTUA use? ▼
Dilkon-Indian Wells-Greasewood-White Cone 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.

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Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.

Read our methodology — how this data is sourced, computed, and verified.

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Data sourced from $official public datasets. See our methodology for details. Retrieved and formatted by PlainWater Editorial