Community Water System · PWS NN3503031
Narbona Pass NTUA
Operator location Ft Defiance, Navajo Nation - 0% of 60 violations are health-based (lower-third health share (≤ 1%)); groundwater source; 862 served per SDWIS.
- 862
- People served (this PWS)
- 60
- EPA violations (this PWS)
- 0
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Narbona Pass NTUA standing, mid SDWIS violation third
0% of 60 recorded violations are health-based - lower-third health share (≤ 1%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 0% is lower-third health share (≤ 1%). Population rank #21,610 of 29,740 among systems serving 500+.
The verdict
Narbona Pass NTUA lands in the middle third by violation volume (60), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is smaller (862; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is only 0% - almost all of this trail is monitoring or reporting. No UCMR5 PFAS test appears for this system in this extract.
- #21,610 of 29,740
- Population · /systems
- #57 of 82
- Population · NN
- 60
- Total EPA violations on record
- 0%
- 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
- 252
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 53
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MR | 3 | 2012 |
| Total Haloacetic Acids (HAA5) | MR | 3 | 2020 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule | MR | 3 | 2013 |
| TTHM | MR | 3 | 2020 |
| Arsenic | MR | 1 | 2008 |
| Barium | MR | 1 | 2008 |
| Cadmium | MR | 1 | 2008 |
| Chromium | MR | 1 | 2008 |
| CYANIDE | MR | 1 | 2008 |
| Mercury | MR | 1 | 2008 |
| Antimony, Total | MR | 1 | 2008 |
| Beryllium, Total | MR | 1 | 2008 |
| Thallium, Total | MR | 1 | 2008 |
| BHC-GAMMA | MR | 1 | 2008 |
| Toxaphene | MR | 1 | 2008 |
| Glyphosate | MR | 1 | 2008 |
| OXAMYL | MR | 1 | 2008 |
| Simazine | MR | 1 | 2008 |
| Dinoseb | MR | 1 | 2008 |
| Carbofuran | MR | 1 | 2008 |
| Atrazine | MR | 1 | 2008 |
| 2,3,7,8-TCDD | MR | 1 | 2008 |
| Heptachlor epoxide | MR | 1 | 2008 |
| HEXACHLOROBENZENE | MR | 1 | 2008 |
| Benzo(a)pyrene | MR | 1 | 2008 |
| Total Polychlorinated Biphenyls (PCB) | MR | 1 | 2008 |
| Gross Alpha, Excl. Radon and U | MR | 1 | 2004 |
| Endrin | MR | 1 | 2008 |
| Fluoride | MR | 1 | 2008 |
| Picloram | MR | 1 | 2008 |
Violation Count vs. the National Corpus
Narbona Pass NTUA has 60 recorded EPA violations, 61% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 38% carry more. 0% of this system's own violations are health-based (0 of 60), and it ranks #21,610 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)
60 Around the middle fewer violations than 38% 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
Health-based violations on Narbona Pass NTUA
0 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for NN3503031.
Sources: EPA SDWIS
Nationwide peers
60 violations · 862 served: nearest cross-state SDWIS matches.
Cross-state systems near this violation count
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems with smaller service footprints
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Narbona Pass NTUA
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Navajo Nation compares on the same EPA violation measures. Navajo Nation systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.