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ST. HELENA, CITY OF

PWS ID: CA2810004 · ST. HELENA, California 94574

ST. HELENA, CITY OF serves 5,386 people in ST. HELENA, California using Surface Water water sources. It has 23 recorded EPA violations, including 19 health-based violations. PFAS "forever chemicals" were detected in UCMR5 testing (1 compound found).

Water Quality Snapshot: ST. HELENA, CITY OF

ST. HELENA, CITY OF is a local-owned community water system that delivers drinking water to 5,386 residents in ST. HELENA, California (Napa County) through 2,551 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 23 total violations for this system , of which 19 (83%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 1 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 Total Haloacetic Acids (HAA5), recorded in 13 violations (MCL, health-based). Under EPA's UCMR5 PFAS monitoring program, 1 PFAS compound was detected in samples collected from this system, with a maximum reported concentration of 75 ppt. PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

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. ST. HELENA, CITY OF's 23 violations sit above 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.

PFAS Detected

1 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
5,386
Total Violations
23
Health-Based Violations
19
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
2,551
County
Napa
School/Daycare
No
MCL Violations
15
Monitoring Violations
1
Treatment Tech Violations
4

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Total Haloacetic Acids (HAA5) MCL 13 2023
Surface Water Treatment Rule TT 4 2020
Coliform (TCR) MCL 2 1995
Lead and Copper Rule MR 1 2022

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 2 of 300 samples detected PFAS.

Contaminant Date Result MRL Status
PFHpS 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFDA 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFMPA 7/12/2023 <0.004 µg/L 0.004 µg/L Not Detected
8:2 FTS 7/12/2023 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
6:2 FTS 7/12/2023 <0.005 µg/L 0.005 µg/L Not Detected
lithium 7/12/2023 <9 µg/L 9 µg/L Not Detected
HFPO-DA 7/12/2023 <0.005 µg/L 0.005 µg/L Not Detected
ADONA 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
9Cl-PF3ONS 7/12/2023 <0.002 µg/L 0.002 µg/L Not Detected
11Cl-PF3OUdS 7/12/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFUnA 7/12/2023 <0.002 µg/L 0.002 µg/L Not Detected
NFDHA 7/12/2023 <0.02 µg/L 0.02 µg/L Not Detected
PFDoA 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
NEtFOSAA 7/12/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFOA 7/12/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFOS 7/12/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFNA 7/12/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFHxS 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFBS 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFTrDA 7/12/2023 <0.007 µg/L 0.007 µg/L Not Detected
PFTA 7/12/2023 <0.008 µg/L 0.008 µg/L Not Detected
PFPeS 7/12/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFEESA 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
NMeFOSAA 7/12/2023 <0.006 µg/L 0.006 µg/L Not Detected
PFHxA 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFBA 7/12/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFMBA 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
NMeFOSAA 7/12/2023 <0.006 µg/L 0.006 µg/L Not Detected
NEtFOSAA 7/12/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFTrDA 7/12/2023 <0.007 µg/L 0.007 µg/L Not Detected
PFTA 7/12/2023 <0.008 µg/L 0.008 µg/L Not Detected
lithium 7/12/2023 54.0000 µg/L 9 µg/L Detected
PFOS 7/12/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFNA 7/12/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFHxS 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpS 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 7/12/2023 <0.02 µg/L 0.02 µg/L Not Detected
PFMPA 7/12/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFPeS 7/12/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFOA 7/12/2023 <0.004 µg/L 0.004 µg/L Not Detected
8:2 FTS 7/12/2023 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 7/12/2023 <0.003 µg/L 0.003 µg/L Not Detected
6:2 FTS 7/12/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFBA 7/12/2023 <0.005 µg/L 0.005 µg/L Not Detected

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 ST. HELENA, CITY OF.

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 CA2810004 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 ST. HELENA, CITY OF 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 Total Haloacetic Acids (HAA5) MCL 13 SDWIS / CA2810004 / 2456
2022 Lead and Copper Rule MR 1 SDWIS / CA2810004 / 5000
2020 Surface Water Treatment Rule TT 4 SDWIS / CA2810004 / 0200
1995 Coliform (TCR) MCL 2 SDWIS / CA2810004 / 3100

How ST. HELENA, CITY OF Compares

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

Metric ST. HELENA, CITY OF California avg Federal benchmark
Total violations 23 21.1 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 19 8.8 Indicates a contaminant exceeded a federal MCL
PFAS detection 1 compound 64.4% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 5,386 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 ST. HELENA, CITY OF water safe to drink? ▼
ST. HELENA, CITY OF (PWS ID: CA2810004) has 23 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 1 PFAS compound found. This system serves 5,386 people using Surface Water sources.
How many people does ST. HELENA, CITY OF serve? ▼
ST. HELENA, CITY OF serves 5,386 people in ST. HELENA, California. It is a Local-owned system using Surface Water water sources with 2,551 service connections.
What type of violations does ST. HELENA, CITY OF have? ▼
ST. HELENA, CITY OF has 23 total violations: 19 health-based violations (MCL exceedances or treatment failures), 1 monitoring/reporting violations, and 4 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in ST. HELENA, CITY OF water? ▼
Yes. UCMR5 testing detected 1 PFAS compound in ST. HELENA, CITY OF's water supply: lithium. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does ST. HELENA, CITY OF use? ▼
ST. HELENA, CITY OF 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. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.

Read our methodology — how this data is sourced, computed, and verified.

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