Public water system · CA0710004
ActiveBrentwood
At a glance
Brentwood (PWSID CA0710004) is an active community water system in Contra Costa County, California. It reports serving 64,513 people through 21,441 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 9 are health-based, and the most recent began in February 2007.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
64,513
Service connections
21,441
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Brentwood compare with other water systems in Contra Costa County?
By EPA's size categories, Brentwood is a large system (10,001 to 100,000 people). Contra Costa County has 84 active public water systems, and Brentwood is the 3rd-largest of them by population served. Its population served is about 9.6 times the county average of 6,726 people per system, and accounts for 11% of the 564,952 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 Brentwood is about 9.6 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 Brentwood?
EPA lists Brentwood 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. 25 of the 84 active systems in Contra Costa County (30%) are also owned by a local government.
Does Brentwood have drinking water violations?
Of the 12 most recent violations in EPA's records, 9 are health-based, and the most recent began in February 2007. The violations listed here began between October 1992 and February 2007. By type: 9 contaminant level above the legal limit and 3 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (10 of them). EPA lists 12 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 |
|---|---|---|---|---|
| 2007-02-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2000-03-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2000-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1996-12-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1996-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1995-12-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1995-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1993-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1993-02-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1992-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
The 12 most recent 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.
Brentwood: frequently asked questions
Who runs Brentwood?
Brentwood (PWSID CA0710004) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does Brentwood serve?
Brentwood reports serving 64,513 people through 21,441 service connections in Contra Costa County, California.
Where does Brentwood 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 Brentwood have any drinking water violations?
Of the 12 most recent violations in EPA's records, 9 are health-based, and the most recent began in February 2007. 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 Brentwood'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. Of the 12 most recent violations in EPA's records, 9 are health-based, and the most recent began in February 2007. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Brentwood's water quality report?
As a community water system, Brentwood 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 Contra Costa County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Contra Costa Water District | Contra Costa | 198,000 | Community | Surface water |
| City of Antioch | Contra Costa | 115,074 | Community | Surface water |
| City of Pittsburg | Contra Costa | 62,500 | Community | Purchased surface water |
| Diablo Water District | Contra Costa | 43,357 | Community | Purchased surface water |
| City of Martinez | Contra Costa | 30,997 | Community | Purchased surface water |
| Golden State Water Company - Bay Point | Contra Costa | 23,731 | 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, “Brentwood, PWSID CA0710004, California”, https://aquacensus.com/water-systems/california/brentwood-ca0710004 (data as of October 1, 2026).