Public water system · CA4910014
ActiveRohnert Park, City of
At a glance
City of Rohnert Park (PWSID CA4910014) is an active community water system in Sonoma County, California. It reports serving 43,821 people through 10,427 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2021.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
43,821
Service connections
10,427
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does City of Rohnert Park compare with other water systems in Sonoma County?
By EPA's size categories, City of Rohnert Park is a large system (10,001 to 100,000 people). Sonoma County has 441 active public water systems, and City of Rohnert Park is the 3rd-largest of them by population served. Its population served is about 40 times the county average of 1,092 people per system, and accounts for 9.1% of the 481,435 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 Rohnert Park is about 6.5 times 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 Rohnert Park?
EPA lists City of Rohnert Park 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. 58 of the 441 active systems in Sonoma County (13%) are also owned by a local government.
Does City of Rohnert Park have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2021. The violations listed here began between January 2017 and July 2021. By type: 11 monitoring and reporting and 1 monitoring. The contaminant or rule involved most often is trans-1,2-Dichloroethylene (2 of them). EPA lists 12 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 |
|---|---|---|---|---|
| 2021-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Arseniccode 1005 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | trans-1,2-Dichloroethylenecode 2979 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,1-Trichloroethanecode 2981 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | trans-1,2-Dichloroethylenecode 2979 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Toluenecode 2991 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Carbon tetrachloridecode 2982 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylbenzenecode 2992 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Xylenes, Totalcode 2955 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Trichloroethylenecode 2984 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | cis-1,2-Dichloroethylenecode 2380 | No | Resolved |
The 12 most recent 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 Rohnert Park: frequently asked questions
Who runs City of Rohnert Park?
City of Rohnert Park (PWSID CA4910014) 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 Rohnert Park serve?
City of Rohnert Park reports serving 43,821 people through 10,427 service connections in Sonoma County, California.
Where does City of Rohnert Park 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 Rohnert Park have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 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 City of Rohnert Park'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. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 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 City of Rohnert Park's water quality report?
As a community water system, City of Rohnert Park 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 Sonoma County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Santa Rosa, City of | Sonoma | 175,396 | Community | Groundwater |
| Petaluma, City of | Sonoma | 60,781 | Community | Groundwater |
| Windsor, Town of | Sonoma | 25,561 | Community | Groundwater |
| Valley of the Moon Water District | Sonoma | 23,107 | Community | Groundwater |
| Sonoma, City of | Sonoma | 11,725 | Community | Groundwater |
| Sonoma State University | Sonoma | 10,986 | Community | Groundwater |
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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, “Rohnert Park, City of, PWSID CA4910014, California”, https://aquacensus.com/water-systems/california/rohnert-park-city-of-ca4910014 (data as of October 1, 2026).