Water Quality in 94101 — San Francisco, CA
EPA data for PRESIDIO OF SAN FRANCISCO
Data source: U.S. Environmental Protection Agency (EPA) SDWIS Last verified: March 16, 2026
Your Water System
ZIP code 94101 in San Francisco, California is served by PRESIDIO OF SAN FRANCISCO (EPA ID: CA3810700). This system provides water to approximately 3,500 people from surface water sources.
There are 4 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 |
|---|---|---|---|
| July 1, 2024 | Contaminant 0700 | Health-based | Unresolved |
| July 1, 2024 | Contaminant 0700 | Health-based | Unresolved |
| June 1, 2024 | Contaminant 0700 | Health-based | Unresolved |
| June 1, 2024 | Contaminant 0700 | Health-based | Unresolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for water systems serving this ZIP code:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Contaminant 0700 | Other | 9 | Yes |
| Lead | Inorganic | 3 | No |
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 |
|---|---|---|---|
| PRESIDIO OF SAN FRANCISCO | CA3810700 | 3,500 | Surface water |
| SIX ACRES WATER COMPANY | CA4900608 | 66 | Surface water |
| SONOMA COUNTY MUTUAL WATER COMPANY | CA4900640 | 40 | Surface water |
| SUNRISE MOBILEHOME PARK | CA4500104 | 37 | Groundwater |
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
- 94601 (Oakland) — 11 mi
- 94518 (Concord) — 24 mi — 4 violations
- 94536 (Fremont) — 27 mi — 18 violations
- 94540 (Hayward) — 27 mi
- 95050 (Santa Clara) — 38 mi
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for PRESIDIO OF SAN FRANCISCO (CA3810700) on EPA.gov.
Frequently Asked Questions
Is the tap water in 94101 safe to drink?
San Francisco’s water system has recorded 9 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 94101’s water come from?
The primary water source for this area is surface water. PRESIDIO OF SAN FRANCISCO serves approximately 3,500 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 94101 have lead in the water?
No Lead and Copper Rule sampling data is currently available in EPA records for water systems serving ZIP code 94101. If you are concerned about lead, contact your water utility or have your tap water independently tested.
What is the radon risk in 94101?
Radon zone data is not available for ZIP code 94101. The EPA recommends testing all homes for radon regardless of location, as radon levels can vary significantly even within the same neighborhood.