A90/100
CWSC LOS ALTOS SUBURBAN — Water Quality Report 2026
Serving 69,973 people · California
Water Source
Purchased Surface Water
County
—
System ID
CA4310001
Violations
3
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.002 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2002.
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 CWSC LOS ALTOS SUBURBAN
Is CWSC LOS ALTOS SUBURBAN water safe to drink?
CWSC LOS ALTOS SUBURBAN water receives a grade of A (90/100), which is considered excellent. 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 CWSC LOS ALTOS SUBURBAN detected?
69 contaminants were tested in CWSC LOS ALTOS SUBURBAN's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does CWSC LOS ALTOS SUBURBAN have any EPA violations?
Yes, CWSC LOS ALTOS SUBURBAN has 3 EPA violation(s) on record, with the most recent in 2002. Violation types include MR, MCL. 1 are health-based violations.
How many people does CWSC LOS ALTOS SUBURBAN serve?
CWSC LOS ALTOS SUBURBAN serves approximately 69,973 people, California.
What type of water does CWSC LOS ALTOS SUBURBAN provide?
CWSC LOS ALTOS SUBURBAN 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 CA4310001.
How does CWSC LOS ALTOS SUBURBAN compare to other utilities in California?
CWSC LOS ALTOS SUBURBAN scores 90/100 with a grade of A (excellent). This places it among the higher-performing utilities in the state. Visit our California state page for a full comparison of water systems.