Public water system · CA4910009
ActiveSanta Rosa, City of
At a glance
City of Santa Rosa (PWSID CA4910009) is an active community water system in Sonoma County, California. It reports serving 175,396 people through 54,167 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's Safe Drinking Water Act records list no violations for this system.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
175,396
Service connections
54,167
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does City of Santa Rosa compare with other water systems in Sonoma County?
By EPA's size categories, City of Santa Rosa is a very large system (more than 100,000 people). Sonoma County has 441 active public water systems, and City of Santa Rosa is the largest of them by population served. Its population served is about 161 times the county average of 1,092 people per system, and accounts for 36% 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 Santa Rosa is about 26 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 Santa Rosa?
EPA lists City of Santa Rosa 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 Santa Rosa have drinking water violations?
No SDWA violations on record.
EPA's SDWA violation and enforcement data (via EPA ECHO, updated quarterly) lists no violations for City of Santa Rosa. For the latest compliance status, check EPA ECHO for current compliance history.
City of Santa Rosa: frequently asked questions
Who runs City of Santa Rosa?
City of Santa Rosa (PWSID CA4910009) 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 Santa Rosa serve?
City of Santa Rosa reports serving 175,396 people through 54,167 service connections in Sonoma County, California.
Where does City of Santa Rosa 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 Santa Rosa have any drinking water violations?
EPA's Safe Drinking Water Act records list no violations for this system.
Is City of Santa Rosa'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 Safe Drinking Water Act records list no violations for this system. 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 Santa Rosa's water quality report?
As a community water system, City of Santa Rosa 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 |
|---|---|---|---|---|
| Petaluma, City of | Sonoma | 60,781 | Community | Groundwater |
| Rohnert Park, City of | Sonoma | 43,821 | 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, “Santa Rosa, City of, PWSID CA4910009, California”, https://aquacensus.com/water-systems/california/santa-rosa-city-of-ca4910009 (data as of October 1, 2026).