PlainWater

Community Water System · PWS CA0410018

Del Oro Water Co.-Stirling Bluffs

Chico, California 95927 - drinking water served from surface water sources to 521 people, tracked in EPA SDWIS and UCMR5.

521
People served
14
EPA violations
14
Health-based
Untested
UCMR5 result

The verdict

EPA records 14 drinking-water violations at Del Oro Water Co.-Stirling Bluffs, 100% of them health-based - below the California per-system average.

14
Total EPA violations on record
100%
Health-based (MCL / treatment failure)
521
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Del Oro Water Co.-Stirling Bluffs

Del Oro Water Co.-Stirling Bluffs is a private-owned community water system that delivers drinking water to 521 residents in Chico, California (Butte County) through 158 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 14 total violations for this system , of which 14 (100%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. The most recent violation on record dates to 2006.

The most frequently cited contaminant at this system is Surface Water Treatment Rule, recorded in 14 violations (TT, health-based). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across California, EPA tracks 7,249 public water systems serving 42,404,883 people, with 153,308 cumulative violations and 63,983 health-based violations on record. About 89% of systems in the state carry at least one violation, and state-wide the average per system is 21.1 violations. Statewide, 447 of 694 UCMR5-tested systems have reported PFAS detections (64.4%).

Del Oro Water Co.-Stirling Bluffs's 14 violations sit below the California average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
521
Total Violations
14
Health-Based Violations
14
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Private
Connections
158
County
Butte
School/Daycare
No
MCL Violations
0
Monitoring Violations
0
Treatment Tech Violations
14

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Surface Water Treatment Rule TT 14 2006

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Del Oro Water Co.-Stirling Bluffs.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID CA0410018 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

California Drinking Water Authority

California State Water Resources Control Board, Division of Drinking Water is the primacy agency that licenses and inspects Del Oro Water Co.-Stirling Bluffs under EPA-delegated authority.

Open CA regulator portal

Source: California State Water Resources Control Board, Division of Drinking Water

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2006 Surface Water Treatment Rule TT 14 SDWIS / CA0410018 / 0200

How Del Oro Water Co.-Stirling Bluffs Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Del Oro Water Co.-Stirling Bluffs California avg Federal benchmark
Total violations 14 21.1 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 14 8.8 Indicates a contaminant exceeded a federal MCL
PFAS detection None 64.4% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 521 5,850 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 7,249 regulated public water systems in California.

Federal MCL reference, Safe Drinking Water Act thresholds
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Del Oro Water Co.-Stirling Bluffs water safe to drink?
Del Oro Water Co.-Stirling Bluffs (PWS ID: CA0410018) has 14 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 521 people using Surface Water sources.
How many people does Del Oro Water Co.-Stirling Bluffs serve?
Del Oro Water Co.-Stirling Bluffs serves 521 people in Chico, California. It is a Private-owned system using Surface Water water sources with 158 service connections.
What type of violations does Del Oro Water Co.-Stirling Bluffs have?
Del Oro Water Co.-Stirling Bluffs has 14 total violations: 14 health-based violations (MCL exceedances or treatment failures), 0 monitoring/reporting violations, and 14 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Del Oro Water Co.-Stirling Bluffs water?
No PFAS testing data is available for Del Oro Water Co.-Stirling Bluffs under the EPA's UCMR5 monitoring program.
What water source does Del Oro Water Co.-Stirling Bluffs use?
Del Oro Water Co.-Stirling Bluffs uses Surface Water as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from?
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.
Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.