County Service Area 11

PWSID: CA4100582

✓

No active violations
This system has no unresolved violations. The most recent violation on record was 2019-06-01.

This system has more violations on record than 93% of water systems in California.

Violation trend: 0.0 per year over the last 5 years, down from 0.2 per year in the previous 5.

System Details

Population Served	450
Service Connections	103
Water Source	Groundwater
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)	0.0006 mg/L	0.015 mg/L	Below Action Level
Lead (90th percentile)	0.0003 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 (30 total)

Contaminant	Violation	Date	Health-Based	Status
8000	TT	2019-06-01	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
3100	MR	1996-04-01		Returned to Compliance
3100	MR	1996-02-01		Returned to Compliance
3100	MR	1996-01-01		Returned to Compliance

Understanding This Water System's Record

County Service Area 11 is a community water system water system that draws from groundwater sources and serves a population of 450 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.