Community Water System · PWS 090400071
Cocopah West
Operator location Somerton, EPA Region 9 — Tribal Water Systems - smaller served population (≤ 999) at 325 people served; 159 SDWIS violations on record from groundwater sources.
- 325
- People served (this PWS)
- 159
- EPA violations (this PWS)
- 4
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Cocopah West standing, high SDWIS violation third
325 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 3% is middle-third health share (≤ 23%).
The verdict
Cocopah West sits in the upper third of the sitemap cohort by violation count (159), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (325; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 3% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- 159
- Total EPA violations on record
- 3%
- Health-based (MCL / treatment failure)
- 325
- 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
- Native American
- Connections
- 90
- School/Daycare
- No
- MCL Violations
- 2
- Monitoring Violations
- 64
- Treatment Tech Violations
- 2
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MR | 23 | 2013 |
| Nitrate | MR | 5 | 2009 |
| Consumer Confidence Rule | Other | 5 | 2006 |
| Lead and Copper Rule | MR | 4 | 2011 |
| Revised Total Coliform Rule | RPT | 3 | 2025 |
| Coliform (TCR) | MCL | 2 | 2008 |
| Total Haloacetic Acids (HAA5) | MR | 2 | 2010 |
| TTHM | MR | 2 | 2010 |
| Groundwater Rule | TT | 2 | 2014 |
| Public Notice | Other | 2 | 2014 |
| Barium | MR | 1 | 1996 |
| Cadmium | MR | 1 | 1996 |
| Mercury | MR | 1 | 1996 |
| Selenium | MR | 1 | 1996 |
| Antimony, Total | MR | 1 | 1996 |
| Thallium, Total | MR | 1 | 1996 |
| Dalapon | MR | 1 | 2004 |
| Diquat | MR | 1 | 2004 |
| Di(2-ethylhexyl) adipate | MR | 1 | 2004 |
| OXAMYL | MR | 1 | 2004 |
| Di(2-ethylhexyl) phthalate | MR | 1 | 2004 |
| Hexachlorocyclopentadiene | MR | 1 | 2004 |
| Total Polychlorinated Biphenyls (PCB) | MR | 1 | 2004 |
| HEXACHLOROBENZENE | MR | 1 | 2004 |
| ETHYLENE DIBROMIDE | MR | 1 | 2004 |
| 2,3,7,8-TCDD | MR | 1 | 2004 |
| Picloram | MR | 1 | 2004 |
| Endothall | MR | 1 | 2004 |
| LASSO | MR | 1 | 2004 |
| Atrazine | MR | 1 | 2004 |
Violation Count vs. the National Corpus
Cocopah West has 159 recorded EPA violations, 82% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 18% carry more. 3% of this system's own violations are health-based (4 of 159), 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)
159 Higher than most more violations than 82% 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 Cocopah West
EPA SDWIS lists 325 people served and 90 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS
Nationwide peers
159 violations · 325 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 Cocopah West
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in EPA Region 9 — Tribal Water Systems compares on the same EPA violation measures. EPA Region 9 — Tribal Water Systems 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.