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CLEARLAKE OAKS COUNTY WATER DISTRICT

PWS ID: CA1710001 · CLEARLAKE OAK, California 95423

CLEARLAKE OAKS COUNTY WATER DISTRICT serves 2,359 people in CLEARLAKE OAK, California using Surface Water water sources. It has 21 recorded EPA violations, including 8 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: CLEARLAKE OAKS COUNTY WATER DISTRICT

CLEARLAKE OAKS COUNTY WATER DISTRICT is a local-owned community water system that delivers drinking water to 2,359 residents in CLEARLAKE OAK, California (Lake County) through 2,161 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 21 total violations for this system , of which 8 (38%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 11 monitoring and reporting violations are on file. The most recent violation on record dates to 2023.

The most frequently cited contaminant at this system is Lead and Copper Rule, recorded in 7 violations (MR). 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. CLEARLAKE OAKS COUNTY WATER DISTRICT's 21 violations sit below the California average. Statewide, 447 of 694 UCMR5-tested systems have reported PFAS detections (64.4%). 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
2,359
Total Violations
21
Health-Based Violations
8
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
2,161
County
Lake
School/Daycare
No
MCL Violations
6
Monitoring Violations
11
Treatment Tech Violations
2

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Lead and Copper Rule MR 7 2019
TTHM MCL 6 2023
Surface Water Treatment Rule TT 2 2006
Nitrate MR 2 2019
Surface Water Treatment Rule MR 2 2017

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 CLEARLAKE OAKS COUNTY WATER DISTRICT.

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 CA1710001 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 CLEARLAKE OAKS COUNTY WATER DISTRICT 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
2023 TTHM MCL 6 SDWIS / CA1710001 / 2950
2019 Lead and Copper Rule MR 7 SDWIS / CA1710001 / 5000
2019 Nitrate MR 2 SDWIS / CA1710001 / 1040
2017 Surface Water Treatment Rule MR 2 SDWIS / CA1710001 / 0200
2006 Surface Water Treatment Rule TT 2 SDWIS / CA1710001 / 0200

How CLEARLAKE OAKS COUNTY WATER DISTRICT Compares

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

Metric CLEARLAKE OAKS COUNTY WATER DISTRICT California avg Federal benchmark
Total violations 21 21.1 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 8 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 2,359 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
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is CLEARLAKE OAKS COUNTY WATER DISTRICT water safe to drink?
CLEARLAKE OAKS COUNTY WATER DISTRICT (PWS ID: CA1710001) has 21 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 2,359 people using Surface Water sources.
How many people does CLEARLAKE OAKS COUNTY WATER DISTRICT serve?
CLEARLAKE OAKS COUNTY WATER DISTRICT serves 2,359 people in CLEARLAKE OAK, California. It is a Local-owned system using Surface Water water sources with 2,161 service connections.
What type of violations does CLEARLAKE OAKS COUNTY WATER DISTRICT have?
CLEARLAKE OAKS COUNTY WATER DISTRICT has 21 total violations: 8 health-based violations (MCL exceedances or treatment failures), 11 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in CLEARLAKE OAKS COUNTY WATER DISTRICT water?
No PFAS testing data is available for CLEARLAKE OAKS COUNTY WATER DISTRICT under the EPA's UCMR5 monitoring program.
What water source does CLEARLAKE OAKS COUNTY WATER DISTRICT use?
CLEARLAKE OAKS COUNTY WATER DISTRICT 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.

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Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

Related

Data sourced from $official public datasets. See our methodology for details. Retrieved and formatted by PlainWater Editorial