Public water system · CA4300740
ActiveMountain Springs Mutual Water Company
At a glance
Mountain Springs Mutual Water Company (PWSID CA4300740) is an active community water system in Santa Clara County, California. It reports serving 40 people through 18 service connections. Its primary water source is purchased surface water, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in December 2017.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
40
Service connections
18
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Mountain Springs Mutual Water Company compare with other water systems in Santa Clara County?
By EPA's size categories, Mountain Springs Mutual Water Company 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 Mountain Springs Mutual Water Company 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 Mountain Springs Mutual Water Company?
EPA lists Mountain Springs Mutual Water Company 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 Mountain Springs Mutual Water Company have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in December 2017. The violations listed here began between March 1984 and December 2017. By type: 6 monitoring and reporting, 4 public notice, recordkeeping or other, 1 monitoring and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (6 of them). EPA lists 8 as resolved and 4 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 |
|---|---|---|---|---|
| 2017-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2015-04-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2015-04-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2003-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2002-09-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2000-02-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1994-10-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1984-09-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-08-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-07-01 | 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 |
The 12 most recent 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.
Mountain Springs Mutual Water Company: frequently asked questions
Who runs Mountain Springs Mutual Water Company?
Mountain Springs Mutual Water Company (PWSID CA4300740) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Mountain Springs Mutual Water Company serve?
Mountain Springs Mutual Water Company reports serving 40 people through 18 service connections in Santa Clara County, California.
Where does Mountain Springs Mutual Water Company 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 Mountain Springs Mutual Water Company have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in December 2017. 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 Mountain Springs Mutual Water Company'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. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in December 2017. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Mountain Springs Mutual Water Company's water quality report?
As a community water system, Mountain Springs Mutual Water Company 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, “Mountain Springs Mutual Water Company, PWSID CA4300740, California”, https://aquacensus.com/water-systems/california/mountain-springs-mutual-water-company-ca4300740 (data as of October 1, 2026).