B77/100
CALIFORNIA WATER SERVICE - SAN CARLOS — Water Quality Report 2026
Serving 35,344 people · California
Water Source
Purchased Surface Water
County
—
System ID
CA4110007
Violations
4
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.006 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2015.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Frequently Asked Questions About CALIFORNIA WATER SERVICE - SAN CARLOS
Is CALIFORNIA WATER SERVICE - SAN CARLOS water safe to drink?
CALIFORNIA WATER SERVICE - SAN CARLOS water receives a grade of B (77/100), which is considered good. Out of 69 contaminants tested, none exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has CALIFORNIA WATER SERVICE - SAN CARLOS detected?
69 contaminants were tested in CALIFORNIA WATER SERVICE - SAN CARLOS's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does CALIFORNIA WATER SERVICE - SAN CARLOS have any EPA violations?
Yes, CALIFORNIA WATER SERVICE - SAN CARLOS has 4 EPA violation(s) on record, with the most recent in 2015. Violation types include TT, MCL. 4 are health-based violations.
How many people does CALIFORNIA WATER SERVICE - SAN CARLOS serve?
CALIFORNIA WATER SERVICE - SAN CARLOS serves approximately 35,344 people, California.
What type of water does CALIFORNIA WATER SERVICE - SAN CARLOS provide?
CALIFORNIA WATER SERVICE - SAN CARLOS sources its water from purchased surface water. Surface water comes from rivers, lakes, or reservoirs and typically requires more extensive treatment. The utility's system ID is CA4110007.
How does CALIFORNIA WATER SERVICE - SAN CARLOS compare to other utilities in California?
CALIFORNIA WATER SERVICE - SAN CARLOS scores 77/100 with a grade of B (good). This is an above-average performance for utilities statewide. Visit our California state page for a full comparison of water systems.