California · population 64,660
Lead pipes in South San Francisco, CA
15,446 lines still unidentified
Most of South San Francisco (population 64,660) gets its water from California Water Service-S San Francisco. It reported no confirmed lead service lines, but 15,446 of 17,175 lines are still listed as unknown material, so lead hasn't been ruled out.
0% of California Water Service-S San Francisco's service lines are lead or galvanized requiring replacement, lower than the California average (0.1%) and lower than the national average (3.1%).
- Lead 0%
- Galvanized (replace) 0%
- Unknown 90%
- Non-lead 10%
Latest lead test for California Water Service-S San Francisco (Jan 2023–Dec 2025): 4.1 ppb at the 90th percentile, against a 15 ppb federal action level. Full test history.
Compliance record: EPA lists no Lead and Copper Rule violations since 2015 for California Water Service-S San Francisco.
Water systems serving South San Francisco
| Water system | Lead | Galv. | Unknown | % lead |
|---|---|---|---|---|
| California Water Service-S San FranciscoMain system | 0 | 0 | 15,446 | 0% |
| City of BrisbaneServes nearby areas | 0 | 0 | 0 | 0% |
Matched from EPA water system service area boundaries and the cities each system reports serving. Edges of the city may be served by a neighboring system; your water bill names your utility.
Check your address in South San Francisco
The counts above cover the whole water system. To see whether your line is lead, look up your address on California Water Service-S San Francisco's official inventory. Utilities had to make these public by October 16, 2024.
No map yet? Do the 2-minute scratch and magnet test.
Protect your drinking water
If your line is lead, galvanized or unknown, use a filter certified to NSF/ANSI 53 for lead for drinking, cooking and baby formula, and use only cold water.
Choosing a lead-certified filter · Testing your water · Replacement cost
Nearby cities
- Brisbaneno lead reported
- San Brunono lead reported
- Millbraeno lead reported
- Colma15,446 unknown
- Burlingameno lead reported
- Dalyno lead reported
- Pacificano lead reported
- Hillsboroughno lead reported
Check another water system
Questions
Does South San Francisco, CA have lead pipes?
None are confirmed, but California Water Service-S San Francisco still lists 15,446 service lines as unknown material.
Who supplies water to South San Francisco?
EPA's service area maps place most of South San Francisco in California Water Service-S San Francisco's service area (PWSID CA4110009). City of Brisbane also serves parts of the city or nearby areas.
How do I check whether my South San Francisco home has a lead service line?
Search your address on California Water Service-S San Francisco's service line inventory map. You can also scratch the pipe where water enters your home: lead is soft, dull gray, scratches to shiny silver and doesn't attract a magnet.
When will lead pipes in South San Francisco be replaced?
EPA's Lead and Copper Rule Improvements require most systems to replace lead and galvanized-requiring-replacement lines by December 31, 2037. Ask California Water Service-S San Francisco whether your street is scheduled and whether it covers the private side.