County Service Area 7
PWSID: CA4100509
This system has no unresolved violations. The most recent violation on record was 2025-01-01.
This system has more violations on record than 93% of water systems in California.
Violation trend: 0.4 per year over the last 5 years, down from 1.0 per year in the previous 5.
System Details
| Population Served | 300 |
| Service Connections | 68 |
| Water Source | Surface Water |
| System Type | Community Water System |
| Owner | Local Government |
| Status | Active |
| City | Redwood City |
| EPA ZIP on File | 94063 |
Lead & Copper Testing
| Contaminant | Level | EPA Action Level | Status |
|---|---|---|---|
| Lead (90th percentile) | 0.0460 mg/L | 0.015 mg/L | Exceeds Action Level |
| Lead (90th percentile) | 0.0058 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0041 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0035 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0033 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0028 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0024 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0019 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0018 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0017 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0011 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 (33 total)
| Contaminant | Violation | Date | Health-Based | Status |
|---|---|---|---|---|
| 2456 | MCL Measured: 0.0640 MG/L (limit: 0.0600 MG/L) | 2025-01-01 | Yes | Acknowledged |
| 2456 | MCL Measured: 0.0640 MG/L (limit: 0.0600 MG/L) | 2025-01-01 | Yes | Returned to Compliance |
| 2456 | MCL Measured: 0.0730 MG/L (limit: 0.0600 MG/L) | 2020-01-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.1150 MG/L (limit: 0.0800 MG/L) | 2018-04-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.1006 MG/L (limit: 0.0800 MG/L) | 2018-01-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0913 MG/L (limit: 0.0800 MG/L) | 2017-10-01 | Yes | Returned to Compliance |
| 2950 | MCL Measured: 0.0900 UG/L (limit: 0.0800 UG/L) | 2017-07-01 | Yes | Returned to Compliance |
| 2982 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2991 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2990 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2989 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2992 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2964 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2987 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2218 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2978 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2977 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2981 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2985 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2988 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2980 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2968 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2983 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2979 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2378 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2413 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2969 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2976 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2984 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2380 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2996 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2955 | MR | 2004-01-01 | Major | Returned to Compliance |
| 2904 | MR | 2004-01-01 | Major | Returned to Compliance |
Understanding This Water System's Record
County Service Area 7 is a community water system water system that draws from surface water sources and serves a population of 300 in Redwood City, 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.