Berryessa Highlands
PWSID: CA2810013
This system has no unresolved violations. The most recent violation on record was 2024-08-01.
This system has more violations on record than 96% of water systems in California.
Violation trend: 0.8 per year over the last 5 years, down from 6.8 per year in the previous 5.
System Details
| Population Served | 715 |
| Service Connections | 256 |
| Water Source | Surface Water |
| System Type | Community Water System |
| Owner | Local Government |
| Status | Active |
| City | Napa |
| EPA ZIP on File | 94559 |
Lead & Copper Testing
| Contaminant | Level | EPA Action Level | Status |
|---|---|---|---|
| Lead (90th percentile) | 0.1025 mg/L | 0.015 mg/L | Exceeds Action Level |
| Lead (90th percentile) | 0.0000 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0000 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0000 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0000 mg/L | 0.015 mg/L | Below Action Level |
Violation History (50 total)
| Contaminant | Violation | Date | Health-Based | Status |
|---|---|---|---|---|
| 8000 | MON | 2024-08-01 | Major | Acknowledged |
| 8000 | MON | 2024-08-01 | Major | Acknowledged |
| 8000 | MON | 2024-08-01 | Major | Acknowledged |
| 8000 | MON | 2024-08-01 | Major | Acknowledged |
| 8000 | MON | 2020-12-01 | Major | Acknowledged |
| 8000 | MON | 2020-12-01 | Major | Acknowledged |
| 2950 | MCL Measured: 0.0823 MG/L (limit: 0.0800 MG/L) | 2020-04-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0823 MG/L (limit: 0.0800 MG/L) | 2020-04-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0863 MG/L (limit: 0.0800 MG/L) | 2020-01-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0863 MG/L (limit: 0.0800 MG/L) | 2020-01-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0870 MG/L (limit: 0.0800 MG/L) | 2019-10-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0870 MG/L (limit: 0.0800 MG/L) | 2019-10-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0845 MG/L (limit: 0.0800 MG/L) | 2019-07-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0845 MG/L (limit: 0.0800 MG/L) | 2019-07-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0910 MG/L | 2019-04-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0910 MG/L | 2019-04-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 89.80 UG/L | 2019-01-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 89.80 UG/L | 2019-01-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0900 MG/L | 2018-10-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0900 MG/L | 2018-10-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 91.80 UG/L | 2018-07-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 91.80 UG/L | 2018-07-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 84.30 UG/L | 2018-04-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 84.30 UG/L | 2018-04-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.1000 MG/L | 2018-01-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.1000 MG/L | 2018-01-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0960 MG/L | 2017-10-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0960 MG/L | 2017-10-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0970 MG/L | 2017-07-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0970 MG/L | 2017-07-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0990 MG/L | 2017-04-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0990 MG/L | 2017-04-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0867 MG/L (limit: 0.0800 MG/L) | 2017-01-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0867 MG/L (limit: 0.0800 MG/L) | 2017-01-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0910 MG/L (limit: 0.0800 MG/L) | 2016-10-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0910 MG/L (limit: 0.0800 MG/L) | 2016-10-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 89.25 UG/L (limit: 80.00 UG/L) | 2016-07-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 89.25 UG/L (limit: 80.00 UG/L) | 2016-07-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 89.00 UG/L (limit: 80.00 UG/L) | 2016-04-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 89.00 UG/L (limit: 80.00 UG/L) | 2016-04-01 | Yes | Returned to Compliance |
| 2456 | MCL Measured: 61.60 UG/L (EPA limit: 0.060 mg/L) | 2016-04-01 | Yes | Returned to Compliance |
| 2456 | MCL Measured: 61.60 UG/L (EPA limit: 0.060 mg/L) | 2016-04-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 89.00 UG/L (limit: 80.00 UG/L) | 2016-01-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 89.00 UG/L (limit: 80.00 UG/L) | 2016-01-01 | Yes | Returned to Compliance |
| 7500 | Other | 2014-02-01 | Returned to Compliance | |
| 7500 | Other | 2014-02-01 | Returned to Compliance | |
| 2950 | MR | 2014-01-01 | Major | Returned to Compliance |
| 2950 | MR | 2014-01-01 | Major | Returned to Compliance |
| 2456 | MR | 2014-01-01 | Major | Returned to Compliance |
| 2456 | MR | 2014-01-01 | Major | Returned to Compliance |
Understanding This Water System's Record
Berryessa Highlands is a community water system water system that draws from surface water sources and serves a population of 715 in Napa, California. This page shows its complete compliance history as reported to the EPA's Safe Drinking Water Information System (SDWIS), the federal database that tracks every public water system in the United States.
What Do These Violations Mean?
Health-based violations mean the system exceeded an EPA maximum contaminant level (MCL) or failed to provide required treatment. These indicate potential health risks from contaminants like lead, arsenic, bacteria, nitrates, or disinfection byproducts. Non-health-based violations involve monitoring, reporting, or procedural requirements — the system missed a testing deadline or failed to notify customers, but contaminant levels were not necessarily unsafe.
What Should You Do?
Your water utility is required to publish an annual Consumer Confidence Report (CCR) that details test results and any violations. If your system has active health-based violations, consider a certified water filter rated for the specific contaminants involved. The contaminant guides on this site explain health risks and filter options for common pollutants. For the most current results, contact your water utility directly — EPA data can lag weeks or months behind real-time testing.