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TWAIN HARTE COMMUNITY SERVICES DISTRICT

PWS ID: CA5510005 · TWAIN HARTE, California 95383

TWAIN HARTE COMMUNITY SERVICES DISTRICT serves 2,378 people in TWAIN HARTE, California using Surface Water water sources. It has 5 recorded EPA violations, including 4 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: TWAIN HARTE COMMUNITY SERVICES DISTRICT

TWAIN HARTE COMMUNITY SERVICES DISTRICT is a local-owned community water system that delivers drinking water to 2,378 residents in TWAIN HARTE, California (Tuolumne County) through 1,588 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 5 total violations for this system , of which 4 (80%) 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 2004.

The most frequently cited contaminant at this system is CARBON, TOTAL, recorded in 2 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. TWAIN HARTE COMMUNITY SERVICES DISTRICT's 5 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
2,378
Total Violations
5
Health-Based Violations
4
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
1,588
County
Tuolumne
School/Daycare
No
MCL Violations
0
Monitoring Violations
0
Treatment Tech Violations
4

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
CARBON, TOTAL TT 2 2004
Surface Water Treatment Rule TT 2 1995

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 TWAIN HARTE COMMUNITY SERVICES 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 CA5510005 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 TWAIN HARTE COMMUNITY SERVICES 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
2004 CARBON, TOTAL TT 2 SDWIS / CA5510005 / 2920
1995 Surface Water Treatment Rule TT 2 SDWIS / CA5510005 / 0200

How TWAIN HARTE COMMUNITY SERVICES DISTRICT Compares

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

Metric TWAIN HARTE COMMUNITY SERVICES DISTRICT California avg Federal benchmark
Total violations 5 21.1 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 4 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 2,378 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 TWAIN HARTE COMMUNITY SERVICES DISTRICT water safe to drink?
TWAIN HARTE COMMUNITY SERVICES DISTRICT (PWS ID: CA5510005) has 5 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 2,378 people using Surface Water sources.
How many people does TWAIN HARTE COMMUNITY SERVICES DISTRICT serve?
TWAIN HARTE COMMUNITY SERVICES DISTRICT serves 2,378 people in TWAIN HARTE, California. It is a Local-owned system using Surface Water water sources with 1,588 service connections.
What type of violations does TWAIN HARTE COMMUNITY SERVICES DISTRICT have?
TWAIN HARTE COMMUNITY SERVICES DISTRICT has 5 total violations: 4 health-based violations (MCL exceedances or treatment failures), 0 monitoring/reporting violations, and 4 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in TWAIN HARTE COMMUNITY SERVICES DISTRICT water?
No PFAS testing data is available for TWAIN HARTE COMMUNITY SERVICES DISTRICT under the EPA's UCMR5 monitoring program.
What water source does TWAIN HARTE COMMUNITY SERVICES DISTRICT use?
TWAIN HARTE COMMUNITY SERVICES 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