Public water system · CA1910072
ActiveGswc - Willowbrook
At a glance
Gswc - Willowbrook (PWSID CA1910072) is an active community water system in Los Angeles County, California. It reports serving 10,793 people through 1,467 service connections. Its primary water source is purchased surface water, and EPA lists it as privately owned. EPA's Safe Drinking Water Act records list no violations for this system.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
10,793
Service connections
1,467
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Gswc - Willowbrook compare with other water systems in Los Angeles County?
By EPA's size categories, Gswc - Willowbrook is a large system (10,001 to 100,000 people). Los Angeles County has 275 active public water systems. Its population served is well below the county average of 36,762 people per system, and accounts for 0.1% of the 10,109,668 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 Gswc - Willowbrook is about 61% above 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 Gswc - Willowbrook?
EPA lists Gswc - Willowbrook as privately owned. 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. 150 of the 275 active systems in Los Angeles County (55%) are also privately owned.
Does Gswc - Willowbrook have drinking water violations?
No SDWA violations on record.
EPA's SDWA violation and enforcement data (via EPA ECHO, updated quarterly) lists no violations for Gswc - Willowbrook. For the latest compliance status, check EPA ECHO for current compliance history.
Gswc - Willowbrook: frequently asked questions
Who runs Gswc - Willowbrook?
Gswc - Willowbrook (PWSID CA1910072) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Gswc - Willowbrook serve?
Gswc - Willowbrook reports serving 10,793 people through 1,467 service connections in Los Angeles County, California.
Where does Gswc - Willowbrook 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 Gswc - Willowbrook have any drinking water violations?
EPA's Safe Drinking Water Act records list no violations for this system.
Is Gswc - Willowbrook'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 Safe Drinking Water Act records list no violations for this system. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Gswc - Willowbrook's water quality report?
As a community water system, Gswc - Willowbrook 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 Los Angeles County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Los Angeles-City, Dept. of Water & Power | Los Angeles | 3,875,566 | Community | Surface water |
| Long Beach Utilities Department | Los Angeles | 466,772 | Community | Purchased surface water |
| Santa Clarita Valley Water Agency | Los Angeles | 294,090 | Community | Surface water |
| Gswc - Southwest | Los Angeles | 277,740 | Community | Purchased surface water |
| San Gabriel Valley Water Co.-El Monte | Los Angeles | 248,000 | Community | Groundwater |
| Los Angeles Cwwd 40 Reg 4 & 34 Lancaster | Los Angeles | 208,129 | 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, “Gswc - Willowbrook, PWSID CA1910072, California”, https://aquacensus.com/water-systems/california/gswc-willowbrook-ca1910072 (data as of October 1, 2026).