Community Water System · PWS CA5400665
Del Oro River Island Serv Terr #1
Operator location Chico, California - 80% of 147 violations are health-based (upper-third health share (> 23%)); surface water source; 1,280 served per SDWIS.
- 1,280
- People served (this PWS)
- 147
- EPA violations (this PWS)
- 118
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Del Oro River Island Serv Terr #1 standing, high SDWIS violation third
80% of 147 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 80% is upper-third health share (> 23%). Population rank #17,294 of 29,740 among systems serving 500+.
The verdict
Del Oro River Island Serv Terr #1 sits in the upper third of the sitemap cohort by violation count (147), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is mid-pack at 1,280 (mid served population (≤ 3,309)). Health-based share is 80% - most of this ledger is MCL or treatment-technique exceedance. No UCMR5 PFAS test appears for this system in this extract.
- #17,294 of 29,740
- Population · /systems
- #1,055 of 1,701
- Population · CA
- 147
- Total EPA violations on record
- 80%
- 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
- Private
- Connections
- 388
- County
- Tulare
- School/Daycare
- No
- MCL Violations
- 118
- Monitoring Violations
- 20
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Combined Uranium | MCL | 62 | 2024 |
| Nitrate | MCL | 33 | 2024 |
| Coliform (TCR) | MCL | 23 | 2005 |
| Nitrate | MR | 9 | 2016 |
| Lead and Copper Rule | MR | 5 | 2012 |
| Coliform (TCR) | MR | 4 | 2007 |
| Consumer Confidence Rule | Other | 3 | 2003 |
| Gross Alpha, Excl. Radon and U | MR | 2 | 1981 |
Violation Count vs. the National Corpus
Del Oro River Island Serv Terr #1 has 147 recorded EPA violations, 81% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 19% carry more. 80% of this system's own violations are health-based (118 of 147), and it ranks #17,294 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)
147 Higher than most more violations than 81% 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 Del Oro River Island Serv Terr #1
118 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for CA5400665.
Sources: EPA SDWIS · California State Water Resources Control Board, Division of Drinking Water
Nationwide peers
147 violations · 1,280 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.
Cross-state systems near this population served
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Del Oro River Island Serv Terr #1
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in California compares on the same EPA violation measures. California 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.