PlainWater

CWS-ONYX WATER SYSTEM

PWS ID: CA1510043 · SAN JOSE, California 95112

CWS-ONYX WATER SYSTEM serves 284 people in SAN JOSE, California using Groundwater water sources. It has 5 recorded EPA violations, including 4 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: CWS-ONYX WATER SYSTEM

CWS-ONYX WATER SYSTEM is a private-owned community water system that delivers drinking water to 284 residents in SAN JOSE, California (Kern County) through 195 service connections. Its water is drawn from groundwater 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. A further 1 monitoring and reporting violations are on file. The most recent violation on record dates to 1995.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 4 violations (MCL, 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. CWS-ONYX WATER SYSTEM'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
284
Total Violations
5
Health-Based Violations
4
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
195
County
Kern
School/Daycare
No
MCL Violations
4
Monitoring Violations
1
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MCL 4 1995
Lead and Copper Rule MR 1 1993

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 CWS-ONYX WATER SYSTEM.

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 CA1510043 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 CWS-ONYX WATER SYSTEM 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
1995 Coliform (TCR) MCL 4 SDWIS / CA1510043 / 3100
1993 Lead and Copper Rule MR 1 SDWIS / CA1510043 / 5000

How CWS-ONYX WATER SYSTEM Compares

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

Metric CWS-ONYX WATER SYSTEM 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 284 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 CWS-ONYX WATER SYSTEM water safe to drink?
CWS-ONYX WATER SYSTEM (PWS ID: CA1510043) has 5 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 284 people using Groundwater sources.
How many people does CWS-ONYX WATER SYSTEM serve?
CWS-ONYX WATER SYSTEM serves 284 people in SAN JOSE, California. It is a Private-owned system using Groundwater water sources with 195 service connections.
What type of violations does CWS-ONYX WATER SYSTEM have?
CWS-ONYX WATER SYSTEM has 5 total violations: 4 health-based violations (MCL exceedances or treatment failures), 1 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in CWS-ONYX WATER SYSTEM water?
No PFAS testing data is available for CWS-ONYX WATER SYSTEM under the EPA's UCMR5 monitoring program.
What water source does CWS-ONYX WATER SYSTEM use?
CWS-ONYX WATER SYSTEM uses Groundwater 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.

Explore PlainWater

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