San Luis Obispo, California Water Quality Report
Water quality data for 25 water systems serving 69,873 people.
Water Source
Detected Contaminants
| Contaminant | Detected Level | EPA Limit (MCL) | Health Guideline | % of Limit | Status |
|---|---|---|---|---|---|
| lithium | 10.0 | No federal limit | 10.0 ug/L(EPA/USGS HBSL) | 100% | Near guideline |
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Compliance & Violations
Active Violations (7)
2E
Oct 17, 2024
4G
Oct 17, 2024
Violation
Unknown
Violation
Unknown
Violation
Unknown
Violation
Unknown
Violation
Unknown
Resolved Violations (165)
01
Jul 1, 2025 — Sep 30, 2025
1A
Apr 1, 2025 — Apr 30, 2025
01
Apr 1, 2025 — Jun 30, 2025
1A
Apr 1, 2025 — Apr 30, 2025
01
Jan 1, 2025 — Mar 31, 2025
+ 160 more resolved violations
Frequently Asked Questions
Is San Luis Obispo tap water safe to drink?
San Luis Obispo's water meets all EPA maximum contaminant levels. However, 1 contaminants were detected at various levels. Some residents may prefer additional filtration for peace of mind.
What contaminants are in San Luis Obispo tap water?
1 contaminants have been detected in San Luis Obispo's water supply across 25 water systems. See the full contaminant table above for details.
How can I improve my water quality in San Luis Obispo?
Install a water filter rated for the specific contaminants found in San Luis Obispo's water. See our filter recommendations above. You can also request your utility's Consumer Confidence Report for the most current test results.
Does San Luis Obispo have any water quality violations?
Yes, San Luis Obispo currently has 7 active violations. See the violations section above for details.