Public water system · CA4810004
ActiveCity of Rio Vista
At a glance
City of Rio Vista (PWSID CA4810004) is an active community water system in Solano County, California. It reports serving 10,489 people through 5,646 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 6 violations for this system; 3 are health-based, and the most recent began in July 2000.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
10,489
Service connections
5,646
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does City of Rio Vista compare with other water systems in Solano County?
By EPA's size categories, City of Rio Vista is a large system (10,001 to 100,000 people). Solano County has 63 active public water systems. Its population served is about 40% above the county average of 7,509 people per system, and accounts for 2.2% of the 473,083 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 City of Rio Vista is about 56% above 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 City of Rio Vista?
EPA lists City of Rio Vista as owned by a local government. 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. 19 of the 63 active systems in Solano County (30%) are also owned by a local government.
Does City of Rio Vista have drinking water violations?
EPA's records list 6 violations for this system; 3 are health-based, and the most recent began in July 2000. The violations listed here began between July 1990 and July 2000. By type: 3 monitoring and reporting and 3 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (3 of them). EPA lists 6 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 |
|---|---|---|---|---|
| 2000-07-01 | Monitoring and reportingMonitoring, Check/Repeat/Confirmation · code 04 | Benzenecode 2990 | No | Resolved |
| 1995-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1994-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1994-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1993-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1990-07-29 | Monitoring and reportingMonitoring, Regular · code 03 | Arseniccode 1005 | No | Resolved |
All 6 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.
City of Rio Vista: frequently asked questions
Who runs City of Rio Vista?
City of Rio Vista (PWSID CA4810004) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does City of Rio Vista serve?
City of Rio Vista reports serving 10,489 people through 5,646 service connections in Solano County, California.
Where does City of Rio Vista 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 City of Rio Vista have any drinking water violations?
EPA's records list 6 violations for this system; 3 are health-based, and the most recent began in July 2000. 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 City of Rio Vista'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 6 violations for this system; 3 are health-based, and the most recent began in July 2000. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find City of Rio Vista's water quality report?
As a community water system, City of Rio Vista 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 Solano County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| City of Vallejo | Solano | 121,420 | Community | Surface water |
| City of Fairfield | Solano | 120,377 | Community | Surface water |
| City of Vacaville | Solano | 99,650 | Community | Surface water |
| Suisun-Solano Water Authority | Solano | 29,105 | Community | Surface water |
| City of Benicia | Solano | 27,131 | Community | Surface water |
| California Water Service Co.-Travis Afb | Solano | 18,111 | 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, “City of Rio Vista, PWSID CA4810004, California”, https://aquacensus.com/water-systems/california/city-of-rio-vista-ca4810004 (data as of October 1, 2026).