A92/100
SAN LUIS OBISPO WATER DEPARTMENT — Water Quality Report 2026
Serving 47,788 people · California
Water Source
Surface Water
County
—
System ID
CA4010009
Violations
1
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
chlorate | 240.00 µg/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 SAN LUIS OBISPO WATER DEPARTMENT
Is SAN LUIS OBISPO WATER DEPARTMENT water safe to drink?
SAN LUIS OBISPO WATER DEPARTMENT water receives a grade of A (92/100), which is considered excellent. Out of 76 contaminants tested, none exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has SAN LUIS OBISPO WATER DEPARTMENT detected?
76 contaminants were tested in SAN LUIS OBISPO WATER DEPARTMENT's water. Notable contaminants include chlorate. No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does SAN LUIS OBISPO WATER DEPARTMENT have any EPA violations?
Yes, SAN LUIS OBISPO WATER DEPARTMENT has 1 EPA violation(s) on record, with the most recent in 2015. Violation types include MCL. 1 are health-based violations.
How many people does SAN LUIS OBISPO WATER DEPARTMENT serve?
SAN LUIS OBISPO WATER DEPARTMENT serves approximately 47,788 people, California.
What type of water does SAN LUIS OBISPO WATER DEPARTMENT provide?
SAN LUIS OBISPO WATER DEPARTMENT sources its water from surface water. Surface water comes from rivers, lakes, or reservoirs and typically requires more extensive treatment. The utility's system ID is CA4010009.
How does SAN LUIS OBISPO WATER DEPARTMENT compare to other utilities in California?
SAN LUIS OBISPO WATER DEPARTMENT scores 92/100 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.