Public water system · CA5601116
ActiveSan Cayetano Mutual Water Co
At a glance
San Cayetano Mutual Water Co (PWSID CA5601116) is an active community water system in Ventura County, California. It reports serving 43 people through 69 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in August 2016.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
43
Service connections
69
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does San Cayetano Mutual Water Co compare with other water systems in Ventura County?
By EPA's size categories, San Cayetano Mutual Water Co is a very small system (500 people or fewer). Ventura County has 95 active public water systems. Its population served is well below the county average of 9,293 people per system, and accounts for less than 0.1% of the 882,799 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 Cayetano 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 San Cayetano Mutual Water Co?
EPA lists San Cayetano 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. 59 of the 95 active systems in Ventura County (62%) are also privately owned.
Does San Cayetano Mutual Water Co have drinking water violations?
EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in August 2016. The violations listed here began between October 1980 and August 2016. By type: 5 monitoring and reporting, 1 monitoring and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (2 of them). EPA lists 5 as resolved and 2 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 |
|---|---|---|---|---|
| 2016-08-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2006-06-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1999-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1996-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1981-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
| 1980-10-30 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
All 7 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 Cayetano Mutual Water Co: frequently asked questions
Who runs San Cayetano Mutual Water Co?
San Cayetano Mutual Water Co (PWSID CA5601116) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does San Cayetano Mutual Water Co serve?
San Cayetano Mutual Water Co reports serving 43 people through 69 service connections in Ventura County, California.
Where does San Cayetano 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 San Cayetano Mutual Water Co have any drinking water violations?
EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in August 2016. 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 Cayetano 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 7 violations for this system; 1 is health-based, and the most recent began in August 2016. 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 Cayetano Mutual Water Co's water quality report?
As a community water system, San Cayetano 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 Ventura County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Oxnard Water Dept | Ventura | 200,232 | Community | Purchased surface water |
| Ventura Water Department | Ventura | 113,500 | Community | Surface water |
| Ventura Wwd No. 8 - Simi Valley | Ventura | 94,738 | Community | Purchased surface water |
| Cal American Water Co | Ventura | 66,809 | Community | Purchased surface water |
| City of Thousand Oaks Water Department | Ventura | 53,157 | Community | Purchased surface water |
| Camarillo Water Dept | Ventura | 46,824 | 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 Cayetano Mutual Water Co, PWSID CA5601116, California”, https://aquacensus.com/water-systems/california/san-cayetano-mutual-water-co-ca5601116 (data as of October 1, 2026).