Public water system · CA1910025
ActiveLos Angeles Cwwd 40, Reg. 39-Rock Creek
At a glance
Los Angeles Cwwd 40, Reg. 39-Rock Creek (PWSID CA1910025) is an active community water system in Los Angeles County, California. It reports serving 994 people through 368 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 November 1982.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
994
Service connections
368
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Los Angeles Cwwd 40, Reg. 39-Rock Creek compare with other water systems in Los Angeles County?
By EPA's size categories, Los Angeles Cwwd 40, Reg. 39-Rock Creek is a small system (501 to 3,300 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 less than 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 Los Angeles Cwwd 40, Reg. 39-Rock Creek is well below 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 Los Angeles Cwwd 40, Reg. 39-Rock Creek?
EPA lists Los Angeles Cwwd 40, Reg. 39-Rock Creek 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. 100 of the 275 active systems in Los Angeles County (36%) are also owned by a local government.
Does Los Angeles Cwwd 40, Reg. 39-Rock Creek have drinking water violations?
EPA's records list one violation for this system; it is not health-based, and the most recent began in November 1982. By type: 1 public notice, recordkeeping or other. EPA lists 1 as archived. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 1982-11-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
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.
Los Angeles Cwwd 40, Reg. 39-Rock Creek: frequently asked questions
Who runs Los Angeles Cwwd 40, Reg. 39-Rock Creek?
Los Angeles Cwwd 40, Reg. 39-Rock Creek (PWSID CA1910025) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does Los Angeles Cwwd 40, Reg. 39-Rock Creek serve?
Los Angeles Cwwd 40, Reg. 39-Rock Creek reports serving 994 people through 368 service connections in Los Angeles County, California.
Where does Los Angeles Cwwd 40, Reg. 39-Rock Creek 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 Los Angeles Cwwd 40, Reg. 39-Rock Creek 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 November 1982. 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 Los Angeles Cwwd 40, Reg. 39-Rock Creek'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 November 1982. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Los Angeles Cwwd 40, Reg. 39-Rock Creek's water quality report?
As a community water system, Los Angeles Cwwd 40, Reg. 39-Rock Creek 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, “Los Angeles Cwwd 40, Reg. 39-Rock Creek, PWSID CA1910025, California”, https://aquacensus.com/water-systems/california/los-angeles-cwwd-40-reg-39-rock-creek-ca1910025 (data as of October 1, 2026).