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Community Water System · PWS NN4933011

Navajo Mountain Community Boarding School BIA

Operator location Tonalea, Navajo Nation - smaller served population (≤ 999) at 163 people served; 88 SDWIS violations on record from groundwater sources.

163
People served (this PWS)
88
EPA violations (this PWS)
6
Health-based (this PWS)
Untested
UCMR5 (this PWS)
Follow published updates (RSS)

Navajo Mountain Community Boarding School BIA standing, high SDWIS violation third

163 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 7% is middle-third health share (≤ 23%).

The verdict

Navajo Mountain Community Boarding School BIA sits in the upper third of the sitemap cohort by violation count (88), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (163; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 7% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.

88
Total EPA violations on record
7%
Health-based (MCL / treatment failure)
163
People served by this PWS (SDWIS)
N/A
PFAS compounds detected (UCMR5)

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

System Details

System Type
Community
Owner Type
Federal
Connections
17
School/Daycare
Yes
MCL Violations
6
Monitoring Violations
50
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Total Haloacetic Acids (HAA5) MR 16 2020
TTHM MR 16 2020
Lead and Copper Rule MR 8 2017
TTHM MCL 6 2018
Coliform (TCR) MR 4 2015
Revised Total Coliform Rule RPT 4 2023
Stage 2 Disinfectants and Disinfection Byproducts Rule MR 3 2013
Revised Total Coliform Rule MON 3 2024
Public Notice Other 3 2018
Revised Total Coliform Rule Other 3 2016
Consumer Confidence Rule Other 2 2024

Violation Count vs. the National Corpus

Navajo Mountain Community Boarding School BIA has 88 recorded EPA violations, 70% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 29% carry more. 7% of this system's own violations are health-based (6 of 88), and it ranks unranked by population served among that same cohort.

EPA violations vs. the national water-system corpus

Public water systems serving 500+ people (EPA SDWIS)

88 Around the middle fewer violations than 29% 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

Population served record for Navajo Mountain Community Boarding School BIA

EPA SDWIS lists 163 people served and 17 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.

Sources: EPA SDWIS

Nationwide peers

88 violations · 163 served: nearest cross-state SDWIS matches.

What to do with Navajo Mountain Community Boarding School BIA

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