Public water system · CA4110013
ActiveCity of Daly City
At a glance
City of Daly City (PWSID CA4110013) is an active community water system in San Mateo County, California. It reports serving 104,901 people through 23,435 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 4 violations for this system; all are health-based, and the most recent began in December 2003.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
104,901
Service connections
23,435
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does City of Daly City compare with other water systems in San Mateo County?
By EPA's size categories, City of Daly City is a very large system (more than 100,000 people). San Mateo County has 51 active public water systems, and City of Daly City is the largest of them by population served. Its population served is about 6.8 times the county average of 15,363 people per system, and accounts for 13% 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 Daly City is about 16 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 Daly City?
EPA lists City of Daly City 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 Daly City have drinking water violations?
EPA's records list 4 violations for this system; all are health-based, and the most recent began in December 2003. The violations listed here began between April 1992 and December 2003. By type: 3 contaminant level above the legal limit and 1 required treatment not met. The contaminant or rule involved most often is Total coliform bacteria (TCR) (3 of them). EPA lists 4 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 |
|---|---|---|---|---|
| 2003-12-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2000-05-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1998-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1992-04-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Surface Water Treatment Rulecode 0200 | Yes | Resolved |
All 4 violations in EPA's records, newest first.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 Daly City: frequently asked questions
Who runs City of Daly City?
City of Daly City (PWSID CA4110013) 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 Daly City serve?
City of Daly City reports serving 104,901 people through 23,435 service connections in San Mateo County, California.
Where does City of Daly City 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 Daly City have any drinking water violations?
EPA's records list 4 violations for this system; all are health-based, and the most recent began in December 2003. 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 Daly City'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 4 violations for this system; all are health-based, and the most recent began in December 2003. 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 Daly City's water quality report?
As a community water system, City of Daly City 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 |
|---|---|---|---|---|
| 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 |
| City of San Bruno | San Mateo | 42,631 | Community | Purchased surface water |
| North Coast County Water Dist | San Mateo | 38,546 | Community | Purchased surface water |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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 Daly City, PWSID CA4110013, California”, https://aquacensus.com/water-systems/california/city-of-daly-city-ca4110013 (data as of October 1, 2026).