Usn San Clemente Island
PWSID: CA3710707
This system has no unresolved violations. The most recent violation on record was 2025-06-01.
This system has more violations on record than 87% of water systems in California.
Violation trend: 3.0 per year over the last 5 years.
System Details
| Population Served | 800 |
| Service Connections | 221 |
| Water Source | Surface Water Purchased |
| System Type | Non-Transient Non-Community |
| Owner | Federal |
| Status | Active |
| City | San Diego |
| EPA ZIP on File | 92135-7088 |
Lead & Copper Testing
| Contaminant | Level | EPA Action Level | Status |
|---|---|---|---|
| Lead (90th percentile) | 0.0884 mg/L | 0.015 mg/L | Exceeds Action Level |
| Lead (90th percentile) | 0.0174 mg/L | 0.015 mg/L | Exceeds Action Level |
| Lead (90th percentile) | 0.0060 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0051 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0051 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0048 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0048 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0031 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0031 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0027 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0027 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0026 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0026 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0022 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0022 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0022 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0021 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0021 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) | 0.0013 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0013 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 (15 total)
| Contaminant | Violation | Date | Health-Based | Status |
|---|---|---|---|---|
| 8000 | MON | 2025-06-01 | Acknowledged | |
| 8000 | MON | 2025-06-01 | Acknowledged | |
| 8000 | MON | 2025-03-01 | Acknowledged | |
| 8000 | MON | 2025-03-01 | Acknowledged | |
| 0200 | TT | 2025-02-01 | Yes | Acknowledged |
| 0200 | TT | 2025-02-01 | Yes | Acknowledged |
| 0200 | TT | 2024-11-01 | Yes | Acknowledged |
| 0200 | TT | 2024-11-01 | Yes | Acknowledged |
| 0200 | TT | 2024-09-01 | Yes | Acknowledged |
| 0200 | TT | 2024-09-01 | Yes | Acknowledged |
| 2456 | MCL Measured: 0.0709 MG/L (limit: 0.0600 MG/L) | 2024-04-01 | Yes | Acknowledged |
| 2456 | MCL Measured: 0.0709 MG/L (limit: 0.0600 MG/L) | 2024-04-01 | Yes | Acknowledged |
| 2456 | MCL Measured: 0.0709 MG/L (limit: 0.0600 MG/L) | 2024-04-01 | Yes | Acknowledged |
| 0200 | TT | 2024-04-01 | Yes | Acknowledged |
| 0200 | TT | 2024-04-01 | Yes | Acknowledged |
Understanding This Water System's Record
Usn San Clemente Island is a non-transient non-community water system that draws from surface water purchased sources and serves a population of 800 in San Diego, 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.