Public water system · CA4110023
ActiveCity of San Bruno
At a glance
City of San Bruno (PWSID CA4110023) is an active community water system in San Mateo County, California. It reports serving 42,631 people through 11,479 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list one violation for this system; it is not health-based, and the most recent began in January 2010.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
42,631
Service connections
11,479
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does City of San Bruno compare with other water systems in San Mateo County?
By EPA's size categories, City of San Bruno is a large system (10,001 to 100,000 people). San Mateo County has 51 active public water systems, and City of San Bruno is the 6th-largest of them by population served. Its population served is about 177% above the county average of 15,363 people per system, and accounts for 5.4% of the 783,522 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active community water system reports serving 6,703 people, so City of San Bruno is about 6.4 times that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. California has 2,997 active community water systems, 40% of the state's 7,479 active systems. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 506 California systems (6.8%) list purchased surface water as their primary source.
Who owns and regulates City of San Bruno?
EPA lists City of San Bruno as owned by a local government. The CA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 19 of the 51 active systems in San Mateo County (37%) are also owned by a local government.
Does City of San Bruno have drinking water violations?
EPA's records list one violation for this system; it is not health-based, and the most recent began in January 2010. By type: 1 monitoring and reporting. The contaminant or rule involved is Nitrate. EPA lists 1 as resolved. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2010-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
The one violation in EPA's records.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
City of San Bruno: frequently asked questions
Who runs City of San Bruno?
City of San Bruno (PWSID CA4110023) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does City of San Bruno serve?
City of San Bruno reports serving 42,631 people through 11,479 service connections in San Mateo County, California.
Where does City of San Bruno get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does City of San Bruno have any drinking water violations?
EPA's records list one violation for this system; it is not health-based, and the most recent began in January 2010. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is City of San Bruno's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. EPA's records list one violation for this system; it is not health-based, and the most recent began in January 2010. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find City of San Bruno's water quality report?
As a community water system, City of San Bruno must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in San Mateo County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| City of Daly City | San Mateo | 104,901 | Community | Purchased surface water |
| California Water Service - San Mateo | San Mateo | 102,348 | Community | Purchased surface water |
| City of Redwood City | San Mateo | 92,819 | Community | Purchased surface water |
| California Water Service-S San Francisco | San Mateo | 64,146 | Community | Purchased surface water |
| California Water Service - Bear Gulch | San Mateo | 61,431 | Community | Surface water |
| North Coast County Water Dist | San Mateo | 38,546 | Community | Purchased surface water |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “City of San Bruno, PWSID CA4110023, California”, https://aquacensus.com/water-systems/california/city-of-san-bruno-ca4110023 (data as of October 1, 2026).