Public water system · CA4301004
ActiveEmerald Valley Mutual Water Company
At a glance
Emerald Valley Mutual Water Company (PWSID CA4301004) is an active community water system in Santa Clara County, California. It reports serving 43 people through 13 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 4 violations for this system; 2 are health-based, and the most recent began in October 2021.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
43
Service connections
13
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Emerald Valley Mutual Water Company compare with other water systems in Santa Clara County?
By EPA's size categories, Emerald Valley 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 Emerald Valley 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. 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 Emerald Valley Mutual Water Company?
EPA lists Emerald Valley 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 Emerald Valley Mutual Water Company have drinking water violations?
EPA's records list 4 violations for this system; 2 are health-based, and the most recent began in October 2021. The violations listed here began between July 2010 and October 2021. By type: 2 contaminant level above the legal limit, 1 monitoring and 1 monitoring and reporting. The contaminant or rule involved most often is Nitrate (3 of them). EPA lists 4 as resolved. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2021-10-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2011-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Resolved |
| 2010-10-01 | Monitoring and reportingMonitoring, Check/Repeat/Confirmation · code 04 | Nitratecode 1040 | No | Resolved |
| 2010-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Resolved |
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.
Emerald Valley Mutual Water Company: frequently asked questions
Who runs Emerald Valley Mutual Water Company?
Emerald Valley Mutual Water Company (PWSID CA4301004) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Emerald Valley Mutual Water Company serve?
Emerald Valley Mutual Water Company reports serving 43 people through 13 service connections in Santa Clara County, California.
Where does Emerald Valley Mutual Water Company 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 Emerald Valley Mutual Water Company have any drinking water violations?
EPA's records list 4 violations for this system; 2 are health-based, and the most recent began in October 2021. 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 Emerald Valley 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. EPA's records list 4 violations for this system; 2 are health-based, and the most recent began in October 2021. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Emerald Valley Mutual Water Company's water quality report?
As a community water system, Emerald Valley 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, “Emerald Valley Mutual Water Company, PWSID CA4301004, California”, https://aquacensus.com/water-systems/california/emerald-valley-mutual-water-company-ca4301004 (data as of October 1, 2026).