Public water system · CA5610035

Active

Rio Manor Mutual Water Co

At a glance

Rio Manor Mutual Water Co (PWSID CA5610035) is an active community water system in Ventura County, California. It reports serving 983 people through 295 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 10 violations for this system; 2 are health-based, and the most recent began in September 2019.

Dataset updated October 2026 . Source: EPA SDWIS/ECHO public records.

Population served

983

Service connections

295

Primary source

Groundwater

System type

CWS

Community water system

System record

PWSIDCA5610035

System typeCommunity water system

Activity statusActive

Population served983

Service connections295

Primary water sourceGroundwater

Owner typePrivate

Primacy agencyCA state drinking water program

City served—

StateCalifornia

ZIP—

CountyVentura County

How does Rio Manor Mutual Water Co compare with other water systems in Ventura County?

By EPA's size categories, Rio Manor Mutual Water Co is a small system (501 to 3,300 people). 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 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 Rio Manor 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 Rio Manor Mutual Water Co?

EPA lists Rio Manor 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 Rio Manor Mutual Water Co have drinking water violations?

EPA's records list 10 violations for this system; 2 are health-based, and the most recent began in September 2019. The violations listed here began between July 1994 and September 2019. By type: 7 monitoring and reporting, 2 contaminant level above the legal limit and 1 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (4 of them). EPA lists 10 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
2019-09-01	MonitoringMonitoring, Routine (RTCR) · code 3A	Revised Total Coliform Rulecode 8000	No	Resolved
2015-02-01	Monitoring and reportingMonitoring, Source Water (GWR) · code 34	E. colicode 3014	No	Resolved
2015-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Resolved
2011-06-01	Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52	Lead and Copper Rulecode 5000	No	Resolved
2008-01-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Total trihalomethanes (TTHM)code 2950	No	Resolved
2008-01-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Haloacetic acids (HAA5)code 2456	No	Resolved
2004-04-19	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Combined Uraniumcode 4006	Yes	Resolved
2003-08-01	Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24	Total coliform bacteria (TCR)code 3100	No	Resolved
2002-10-01	Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24	Total coliform bacteria (TCR)code 3100	No	Resolved
1994-07-01	Monitoring and reportingMonitoring, Routine Major (TCR) · code 23	Total coliform bacteria (TCR)code 3100	No	Resolved

All 10 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.

Rio Manor Mutual Water Co: frequently asked questions

Who runs Rio Manor Mutual Water Co?

Rio Manor Mutual Water Co (PWSID CA5610035) is a community water system privately owned. It is regulated by the CA state drinking water program.

How many people does Rio Manor Mutual Water Co serve?

Rio Manor Mutual Water Co reports serving 983 people through 295 service connections in Ventura County, California.

Where does Rio Manor 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 Rio Manor Mutual Water Co have any drinking water violations?

EPA's records list 10 violations for this system; 2 are health-based, and the most recent began in September 2019. 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 Rio Manor 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 10 violations for this system; 2 are health-based, and the most recent began in September 2019. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.

Where can I find Rio Manor Mutual Water Co's water quality report?

As a community water system, Rio Manor 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, “Rio Manor Mutual Water Co, PWSID CA5610035, California”, https://aquacensus.com/water-systems/california/rio-manor-mutual-water-co-ca5610035 (data as of October 1, 2026).