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Community Water System · PWS NN0400342

Dilkon-Indian Wells-Greasewood-White Cone NTUA

Operator location Fort Defiance, Navajo Nation - 48% of 223 violations are health-based (upper-third health share (> 23%)); groundwater source; 4,986 served per SDWIS.

4,986
People served (this PWS)
223
EPA violations (this PWS)
107
Health-based (this PWS)
No PFAS
UCMR5 (this PWS)
Follow published updates (RSS)

Dilkon-Indian Wells-Greasewood-White Cone NTUA standing, high SDWIS violation third

48% of 223 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 48% is upper-third health share (> 23%). UCMR5: UCMR5 tested, none detected. Population rank #7,768 of 29,740 among systems serving 500+.

The verdict

Dilkon-Indian Wells-Greasewood-White Cone NTUA sits in the upper third of the sitemap cohort by violation count (223), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is large (4,986; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 48% - most of this ledger is MCL or treatment-technique exceedance. UCMR5 tested this system and reported no PFAS above the minimum reporting level.

#7,768 of 29,740
Population · /systems
#6 of 82
Population · NN
223
Total EPA violations on record
48%
Health-based (MCL / treatment failure)

Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.

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

Violation Count vs. the National Corpus

Dilkon-Indian Wells-Greasewood-White Cone NTUA has 223 recorded EPA violations, 87% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 13% carry more. 48% of this system's own violations are health-based (107 of 223), and it ranks #7,768 of 29,740 by population served among that same cohort.

EPA violations vs. the national water-system corpus

Public water systems serving 500+ people (EPA SDWIS)

223 Higher than most more violations than 87% of 29,740 water systems

the national water-system corpus, bucketed by value

Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.

Source EPA SDWIS · 2026-05-15

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 87 samples detected PFAS.

Contaminant Date Result MRL Status
PFDoA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
PFHxA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
PFUnA 6/16/2025 <2.00 ppt 2.00 ppt Not Detected
11Cl-PF3OUdS 6/16/2025 <5.00 ppt 5.00 ppt Not Detected
9Cl-PF3ONS 6/16/2025 <2.00 ppt 2.00 ppt Not Detected
HFPO-DA 6/16/2025 <5.00 ppt 5.00 ppt Not Detected
PFDA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
PFTrDA 6/16/2025 <7.00 ppt 7.00 ppt Not Detected
ADONA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
PFOA 6/16/2025 <4.00 ppt 4.00 ppt Not Detected
PFOS 6/16/2025 <4.00 ppt 4.00 ppt Not Detected
PFNA 6/16/2025 <4.00 ppt 4.00 ppt Not Detected
PFHxS 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
PFHpA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
NEtFOSAA 6/16/2025 <5.00 ppt 5.00 ppt Not Detected
PFTA 6/16/2025 <8.00 ppt 8.00 ppt Not Detected
PFBA 6/16/2025 <5.00 ppt 5.00 ppt Not Detected
PFBS 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
NFDHA 6/16/2025 <20.00 ppt 20.00 ppt Not Detected
6:2 FTS 6/16/2025 <5.00 ppt 5.00 ppt Not Detected
NMeFOSAA 6/16/2025 <6.00 ppt 6.00 ppt Not Detected
PFPeS 6/16/2025 <4.00 ppt 4.00 ppt Not Detected
PFEESA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
PFMBA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
PFPeA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
PFMPA 6/16/2025 <4.00 ppt 4.00 ppt Not Detected
8:2 FTS 6/16/2025 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
PFHpS 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
ADONA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
8:2 FTS 6/16/2025 <5.00 ppt 5.00 ppt Not Detected
PFUnA 6/16/2025 <2.00 ppt 2.00 ppt Not Detected
PFMBA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
PFPeA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
PFMPA 6/16/2025 <4.00 ppt 4.00 ppt Not Detected
4:2 FTS 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
6:2 FTS 6/16/2025 <5.00 ppt 5.00 ppt Not Detected
PFBA 6/16/2025 <5.00 ppt 5.00 ppt Not Detected
PFHxA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
HFPO-DA 6/16/2025 <5.00 ppt 5.00 ppt Not Detected
PFEESA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
9Cl-PF3ONS 6/16/2025 <2.00 ppt 2.00 ppt Not Detected
11Cl-PF3OUdS 6/16/2025 <5.00 ppt 5.00 ppt Not Detected
PFHpS 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
PFPeS 6/16/2025 <4.00 ppt 4.00 ppt Not Detected
PFTA 6/16/2025 <8.00 ppt 8.00 ppt Not Detected
PFTrDA 6/16/2025 <7.00 ppt 7.00 ppt Not Detected
PFDoA 6/16/2025 <3.00 ppt 3.00 ppt Not Detected
NMeFOSAA 6/16/2025 <6.00 ppt 6.00 ppt Not Detected
PFBS 6/16/2025 <3.00 ppt 3.00 ppt Not Detected

Health-based violations on Dilkon-Indian Wells-Greasewood-White Cone NTUA

107 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for NN0400342.

Sources: EPA SDWIS

Nationwide peers

223 violations · 4,986 served: nearest cross-state SDWIS matches.

Cross-state systems with comparable violation load

Nearest cross-state community systems (500+ served) by total SDWIS violations on record.

4 peers

Cross-state systems with similar served population

Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).

4 peers

What to do with Dilkon-Indian Wells-Greasewood-White Cone NTUA

Use this system's EPA-reported record as a starting filter, not a final verdict.

EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater