Water Quality in 93401 — San Luis Obispo, CA
EPA data for SAN LUIS OBISPO WATER DEPARTMENT
Data source: U.S. Environmental Protection Agency (EPA) SDWIS Last verified: March 16, 2026
Your Water System
ZIP code 93401 in San Luis Obispo, California is served by SAN LUIS OBISPO WATER DEPARTMENT (EPA ID: CA4010009). This system provides water to approximately 47,788 people from surface water sources.
There are 22 community water systems serving this area.
Lead & Copper in Your Water
No Lead & Copper Rule sampling data available for systems serving this ZIP code.
Violation Summary
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| April 1, 2025 | Consumer Confidence Report Rule | Health-based | Resolved |
| April 1, 2025 | Consumer Confidence Report Rule | Health-based | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for water systems serving this ZIP code:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| E. coli | Microbiological | 2 | No |
| Consumer Confidence Report Rule | Reporting | 2 | Yes |
Need help with your water quality?
Call to get connected with a local professional in your area.
Call (855) 384-4856This is a free service. You will be connected with an independent service provider.
Water Systems Serving This Area
| System Name | EPA ID | Population | Source |
|---|---|---|---|
| SAN LUIS OBISPO WATER DEPARTMENT | CA4010009 | 47,788 | Surface water |
| CALIFORNIA MENS COLONY | CA4010830 | 15,000 | Surface water |
| LOPEZ PROJECT | CA4010022 | 1,569 | Surface water |
| SLO CWWD NO. 23 - SANTA MARGARITA | CA4010024 | 1,291 | Groundwater |
| SLOCSA #10A - CAYUCOS | CA4010901 | 1,200 | Surface water |
What You Can Do
- Request your water system’s Consumer Confidence Report (CCR) — Your utility is required to publish this annually
- Consider a home water test — Independent testing can reveal issues in your specific plumbing
- Install a certified water filter — NSF-certified filters can address specific contaminants
- Contact your water provider — Ask about current treatment and any ongoing remediation
Need help with water testing or filtration?
Call to get connected with a local professional in your area.
Call (855) 384-4856This is a free service. You will be connected with an independent service provider.
Other Water Quality Reports in California
- 90001 (Los Angeles) — 2 violations
- 90210 (Beverly Hills) — 10 violations
- 90301 (Inglewood) — 4 violations
- 90401 (Santa Monica)
- 90501 (Torrance)
- 90601 (Whittier)
- 90801 (Long Beach) — 42 violations
- 91101 (Pasadena) — 14 violations
- 91201 (Glendale)
- 91501 (Burbank) — 24 violations
- 91801 (Alhambra)
- 91909 (Chula Vista)
- 92008 (Carlsbad)
- 92025 (Escondido)
- 92049 (Oceanside)
- 92101 (San Diego) — 29 violations
- 92331 (Fontana)
- 92401 (San Bernardino)
- 92501 (Riverside)
- 92551 (Moreno Valley)
Nearby Water Quality Reports
- 93101 (Santa Barbara) — 79 mi — 3 violations
- 93301 (Bakersfield) — 92 mi — 17 violations
- 93001 (Ventura) — 98 mi — 22 violations
- 93030 (Oxnard) — 111 mi — 3 violations
- 93901 (Salinas) — 112 mi — 9 violations
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for SAN LUIS OBISPO WATER DEPARTMENT (CA4010009) on EPA.gov.
Frequently Asked Questions
Is the tap water in 93401 safe to drink?
San Luis Obispo’s water system has recorded 2 health-based violations in the past 5 years. While the system is required to treat water to meet federal standards, you may want to consider additional precautions such as a certified water filter.
Where does 93401’s water come from?
The primary water source for this area is surface water. SAN LUIS OBISPO WATER DEPARTMENT serves approximately 47,788 people.
How can I get my water tested?
Contact your local water utility for a free water quality report, or hire a certified lab for independent home water testing. The EPA recommends testing annually if you use a private well.
Does 93401 have lead in the water?
No Lead and Copper Rule sampling data is currently available in EPA records for water systems serving ZIP code 93401. If you are concerned about lead, contact your water utility or have your tap water independently tested.
What is the radon risk in 93401?
Radon zone data is not available for ZIP code 93401. The EPA recommends testing all homes for radon regardless of location, as radon levels can vary significantly even within the same neighborhood.