Public water system · CA4300787
ActiveStonebridge Mutual Water Co
At a glance
Stonebridge Mutual Water Co (PWSID CA4300787) is an active community water system in Santa Clara County, California. It reports serving 38 people through 15 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 6 violations for this system; none is health-based, and the most recent began in August 1984.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
38
Service connections
15
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Stonebridge Mutual Water Co compare with other water systems in Santa Clara County?
By EPA's size categories, Stonebridge Mutual Water Co is a very small system (500 people or fewer). Santa Clara County has 121 active public water systems. Its population served is well below the county average of 17,334 people per system, and accounts for less than 0.1% of the 2,097,447 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 Stonebridge Mutual Water Co 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. 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 Stonebridge Mutual Water Co?
EPA lists Stonebridge Mutual Water Co 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. 82 of the 121 active systems in Santa Clara County (68%) are also privately owned.
Does Stonebridge Mutual Water Co have drinking water violations?
EPA's records list 6 violations for this system; none is health-based, and the most recent began in August 1984. The violations listed here began between October 1982 and August 1984. By type: 6 public notice, recordkeeping or other. EPA lists 6 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 |
|---|---|---|---|---|
| 1984-08-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-06-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-03-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1983-03-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1982-12-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1982-10-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
All 6 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.
Stonebridge Mutual Water Co: frequently asked questions
Who runs Stonebridge Mutual Water Co?
Stonebridge Mutual Water Co (PWSID CA4300787) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Stonebridge Mutual Water Co serve?
Stonebridge Mutual Water Co reports serving 38 people through 15 service connections in Santa Clara County, California.
Where does Stonebridge Mutual Water Co 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 Stonebridge Mutual Water Co have any drinking water violations?
EPA's records list 6 violations for this system; none is health-based, and the most recent began in August 1984. 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 Stonebridge Mutual Water Co'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 6 violations for this system; none is health-based, and the most recent began in August 1984. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Stonebridge Mutual Water Co's water quality report?
As a community water system, Stonebridge Mutual Water Co 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 Santa Clara County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| San Jose Water | Santa Clara | 1,039,920 | Community | Surface water |
| City of Sunnyvale | Santa Clara | 157,566 | Community | Purchased surface water |
| City of Santa Clara | Santa Clara | 130,746 | Community | Purchased surface water |
| Great Oaks Wc Inc. | Santa Clara | 110,088 | Community | Groundwater |
| City of San Jose - Evg/Edv/Coy | Santa Clara | 101,265 | Community | Purchased surface water |
| City of Milpitas | Santa Clara | 81,773 | 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, “Stonebridge Mutual Water Co, PWSID CA4300787, California”, https://aquacensus.com/water-systems/california/stonebridge-mutual-water-co-ca4300787 (data as of October 1, 2026).