Public water system · CA5610010
ActiveCal American Wc - Rio Plaza
At a glance
Cal American Wc - Rio Plaza (PWSID CA5610010) is an active community water system in Ventura County, California. It reports serving 1,709 people through 519 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in June 2015.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,709
Service connections
519
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Cal American Wc - Rio Plaza compare with other water systems in Ventura County?
By EPA's size categories, Cal American Wc - Rio Plaza 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 0.2% 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 Cal American Wc - Rio Plaza 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 Cal American Wc - Rio Plaza?
EPA lists Cal American Wc - Rio Plaza 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 Cal American Wc - Rio Plaza have drinking water violations?
EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in June 2015. The violations listed here began between August 2000 and June 2015. By type: 3 contaminant level above the legal limit and 2 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (4 of them). EPA lists 5 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 |
|---|---|---|---|---|
| 2015-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2009-05-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2003-10-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2001-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2000-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
All 5 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.
Cal American Wc - Rio Plaza: frequently asked questions
Who runs Cal American Wc - Rio Plaza?
Cal American Wc - Rio Plaza (PWSID CA5610010) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Cal American Wc - Rio Plaza serve?
Cal American Wc - Rio Plaza reports serving 1,709 people through 519 service connections in Ventura County, California.
Where does Cal American Wc - Rio Plaza 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 Cal American Wc - Rio Plaza have any drinking water violations?
EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in June 2015. 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 Cal American Wc - Rio Plaza'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 5 violations for this system; 3 are health-based, and the most recent began in June 2015. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Cal American Wc - Rio Plaza's water quality report?
As a community water system, Cal American Wc - Rio Plaza 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, “Cal American Wc - Rio Plaza, PWSID CA5610010, California”, https://aquacensus.com/water-systems/california/cal-american-wc-rio-plaza-ca5610010 (data as of October 1, 2026).