Public water system · CA1910039
ActiveSan Gabriel Valley Water Co.-El Monte
At a glance
San Gabriel Valley Water Co.-El Monte (PWSID CA1910039) is an active community water system in Los Angeles County, California. It reports serving 248,000 people through 46,952 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in June 2019.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
248,000
Service connections
46,952
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does San Gabriel Valley Water Co.-El Monte compare with other water systems in Los Angeles County?
By EPA's size categories, San Gabriel Valley Water Co.-El Monte is a very large system (more than 100,000 people). Los Angeles County has 275 active public water systems, and San Gabriel Valley Water Co.-El Monte is the 5th-largest of them by population served. Its population served is about 6.7 times the county average of 36,762 people per system, and accounts for 2.5% 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 San Gabriel Valley Water Co.-El Monte is about 37 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. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 6,179 California systems (83%) list groundwater as their primary source.
Who owns and regulates San Gabriel Valley Water Co.-El Monte?
EPA lists San Gabriel Valley Water Co.-El Monte 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 San Gabriel Valley Water Co.-El Monte have drinking water violations?
EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in June 2019. The violations listed here began between August 1987 and June 2019. By type: 2 required treatment not met, 1 contaminant level above the legal limit and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Groundwater Rule (2 of them). EPA lists 3 as resolved and 1 as archived. 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. 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 |
|---|---|---|---|---|
| 2019-06-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Groundwater Rulecode 0700 | Yes | Resolved |
| 2018-09-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Groundwater Rulecode 0700 | 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 |
| 1987-08-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
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.
San Gabriel Valley Water Co.-El Monte: frequently asked questions
Who runs San Gabriel Valley Water Co.-El Monte?
San Gabriel Valley Water Co.-El Monte (PWSID CA1910039) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does San Gabriel Valley Water Co.-El Monte serve?
San Gabriel Valley Water Co.-El Monte reports serving 248,000 people through 46,952 service connections in Los Angeles County, California.
Where does San Gabriel Valley Water Co.-El Monte get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does San Gabriel Valley Water Co.-El Monte have any drinking water violations?
EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in June 2019. 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 San Gabriel Valley Water Co.-El Monte'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; 3 are health-based, and the most recent began in June 2019. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find San Gabriel Valley Water Co.-El Monte's water quality report?
As a community water system, San Gabriel Valley Water Co.-El Monte 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 |
| Los Angeles Cwwd 40 Reg 4 & 34 Lancaster | Los Angeles | 208,129 | Community | Purchased surface water |
| Glendale-City, Water Dept. | Los Angeles | 188,784 | 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, “San Gabriel Valley Water Co.-El Monte, PWSID CA1910039, California”, https://aquacensus.com/water-systems/california/san-gabriel-valley-water-co-el-monte-ca1910039 (data as of October 1, 2026).