Public water system record

California Water Service-S San Francisco

Serves South San Francisco, Colma and Broadmoor, San Mateo County, CA · 64,146 people served

Federal records show no health-based violations and no monitoring or reporting issues for California Water Service-S San Francisco in the last ten years.

  • CA4110009
  • SAN JOSE
  • CA
  • 64,146 served

System profile

Source water Purchased surface water
ZIP 95112
EPA system ID CA4110009

Verify this system on EPA ECHO →

Health-based violations, last 10 years
0
Resolved
0
Unresolved
0
Any acute record
No
Monitoring issues, last 10 years
0

Key facts

  • California Water Service-S San Francisco draws water from 6 wells.
  • Most recent formal enforcement: compliance order (no penalty) by California, August 2013.
  • Record on file since 1992, with 2 health-based violations before October 19, 2016.
  • Lead pipe inventory: 0 lead and 15,446 unknown out of 17,175 service lines.

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Health-based violations

Since October 2016

Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.

None since October 2016, and no monitoring or reporting violations either.

Full record since 1992

EPA's records for California Water Service-S San Francisco go back to 1992. Before October 19, 2016 they list 2 health-based violations (2 resolved) and 1 monitoring or reporting violation.

Violations that began in Health-based Monitoring and reporting
1990s 2 0
2010 to October 18, 2016 0 1

Most recent health-based violation before October 19, 2016: Surface Water Treatment Rule, began June 1993, Resolved.

Show all 2 health-based violations before October 19, 2016
Contaminant Start date Status
Surface Water Treatment Rule
Treatment technique failure
Jun 1, 1993 Resolved
Total Coliform
Contaminant limit exceeded
Oct 1, 1992 Resolved

Enforcement actions

California regulators took 2 formal enforcement actions against California Water Service-S San Francisco between 1993 and 2013. The most recent was a compliance order (no penalty) in August 2013.

Date By Action Violations covered
Aug 20, 2013 California Compliance order (no penalty) 1 violation: E. coli
Jun 30, 1993 California Compliance order (no penalty) 1 violation (1 health-based): Surface Water Treatment Rule

Where the water comes from

California Water Service-S San Francisco draws water from 6 wells. It also buys water from San Francisco Regional Water System. It also has an emergency connection to City of Brisbane. 2 other public water systems have emergency connections to California Water Service-S San Francisco.

Buys water from

Emergency or part-time connections to

Annual water quality report

California Water Service-S San Francisco must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.

Systems serving 10,000 or more people must mail or deliver the report to every customer, and from 2027 they must send it twice a year.

Find a posted report with EPA's Consumer Confidence Report search

Testing your own water

To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by California.