Public water system · CA1910189
ActiveSan Gabriel Valley Water Co-Montebello 1
At a glance
San Gabriel Valley Water Co-Montebello 1 (PWSID CA1910189) is an active community water system in Los Angeles County, California. It reports serving 9,630 people through 1,623 service connections. Its primary water source is purchased groundwater, and EPA lists it as privately owned. EPA's records list 5 violations for this system; none is health-based, and the most recent began in January 2009.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
9,630
Service connections
1,623
Primary source
GWP
Purchased groundwater
System type
CWS
Community water system
System record
How does San Gabriel Valley Water Co-Montebello 1 compare with other water systems in Los Angeles County?
By EPA's size categories, San Gabriel Valley Water Co-Montebello 1 is a medium system (3,301 to 10,000 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 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 San Gabriel Valley Water Co-Montebello 1 is about 44% 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 groundwater means the system buys groundwater from another public water system rather than drawing its own. 76 California systems (1%) list purchased groundwater as their primary source.
Who owns and regulates San Gabriel Valley Water Co-Montebello 1?
EPA lists San Gabriel Valley Water Co-Montebello 1 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-Montebello 1 have drinking water violations?
EPA's records list 5 violations for this system; none is health-based, and the most recent began in January 2009. The violations listed here began between August 1987 and January 2009. By type: 4 monitoring and reporting and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Total trihalomethanes (TTHM) (2 of them). EPA lists 4 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 |
|---|---|---|---|---|
| 2009-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2009-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2007-12-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2007-12-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 1987-08-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
All 5 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-Montebello 1: frequently asked questions
Who runs San Gabriel Valley Water Co-Montebello 1?
San Gabriel Valley Water Co-Montebello 1 (PWSID CA1910189) 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-Montebello 1 serve?
San Gabriel Valley Water Co-Montebello 1 reports serving 9,630 people through 1,623 service connections in Los Angeles County, California.
Where does San Gabriel Valley Water Co-Montebello 1 get its water?
EPA SDWIS lists this system's primary water source as purchased groundwater. Purchased groundwater means the system buys groundwater from another public water system rather than drawing its own.
Does San Gabriel Valley Water Co-Montebello 1 have any drinking water violations?
EPA's records list 5 violations for this system; none is health-based, and the most recent began in January 2009. 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-Montebello 1'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 5 violations for this system; none is health-based, and the most recent began in January 2009. 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-Montebello 1's water quality report?
As a community water system, San Gabriel Valley Water Co-Montebello 1 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, “San Gabriel Valley Water Co-Montebello 1, PWSID CA1910189, California”, https://aquacensus.com/water-systems/california/san-gabriel-valley-water-co-montebello-1-ca1910189 (data as of October 1, 2026).