Community Water System · PWS NN0435004
Cottonwood Day School BIA
Operator location Chinle, Navajo Nation - smaller served population (≤ 999) at 185 people served; 113 SDWIS violations on record from groundwater sources.
- 185
- People served (this PWS)
- 113
- EPA violations (this PWS)
- 5
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Cottonwood Day School BIA standing, high SDWIS violation third
185 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 4% is middle-third health share (≤ 23%).
The verdict
Cottonwood Day School BIA sits in the upper third of the sitemap cohort by violation count (113), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (185; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 4% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- 113
- Total EPA violations on record
- 4%
- Health-based (MCL / treatment failure)
- 185
- 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
- 28
- School/Daycare
- Yes
- MCL Violations
- 5
- Monitoring Violations
- 80
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MR | 10 | 2012 |
| Consumer Confidence Rule | Other | 6 | 2006 |
| Di(2-ethylhexyl) phthalate | MCL | 5 | 2012 |
| 2,3,7,8-TCDD | MR | 5 | 2008 |
| Nitrate | MR | 3 | 2024 |
| Revised Total Coliform Rule | RPT | 3 | 2023 |
| Nitrite | MR | 3 | 2024 |
| Revised Total Coliform Rule | MON | 3 | 2025 |
| Di(2-ethylhexyl) phthalate | MR | 2 | 2012 |
| Endrin | MR | 1 | 2004 |
| BHC-GAMMA | MR | 1 | 2004 |
| Methoxychlor | MR | 1 | 2004 |
| Glyphosate | MR | 1 | 2004 |
| OXAMYL | MR | 1 | 2004 |
| Simazine | MR | 1 | 2004 |
| Picloram | MR | 1 | 2004 |
| Dinoseb | MR | 1 | 2004 |
| Hexachlorocyclopentadiene | MR | 1 | 2004 |
| Aldicarb sulfone | MR | 1 | 2004 |
| Carbofuran | MR | 1 | 2004 |
| Heptachlor epoxide | MR | 1 | 2004 |
| 2,4-D | MR | 1 | 2004 |
| 2,4,5-TP | MR | 1 | 2004 |
| HEXACHLOROBENZENE | MR | 1 | 2004 |
| cis-1,2-Dichloroethylene | MR | 1 | 2004 |
| 1,2-DIBROMO-3-CHLOROPROPANE | MR | 1 | 2004 |
| ETHYLENE DIBROMIDE | MR | 1 | 2004 |
| DICHLOROMETHANE | MR | 1 | 2004 |
| Vinyl chloride | MR | 1 | 2004 |
| 1,1-Dichloroethylene | MR | 1 | 2004 |
Violation Count vs. the National Corpus
Cottonwood Day School BIA has 113 recorded EPA violations, 76% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 24% carry more. 4% of this system's own violations are health-based (5 of 113), 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)
113 Higher than most more violations than 76% 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 Cottonwood Day School BIA
EPA SDWIS lists 185 people served and 28 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS
Nationwide peers
113 violations · 185 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.
What to do with Cottonwood Day School BIA
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.