Public water system · CA4901246
ActiveDowntown Graton Mutual Water System
At a glance
Downtown Graton Mutual Water System (PWSID CA4901246) is an active community water system in Sonoma County, California. It reports serving 115 people through 28 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 3 violations for this system; 1 is health-based, and the most recent began in April 2008.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
115
Service connections
28
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Downtown Graton Mutual Water System compare with other water systems in Sonoma County?
By EPA's size categories, Downtown Graton Mutual Water System is a very small system (500 people or fewer). Sonoma County has 441 active public water systems. Its population served is well below the county average of 1,092 people per system, and accounts for less than 0.1% 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 Downtown Graton Mutual Water System 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 Downtown Graton Mutual Water System?
EPA lists Downtown Graton Mutual Water System 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. 371 of the 441 active systems in Sonoma County (84%) are also privately owned.
Does Downtown Graton Mutual Water System have drinking water violations?
EPA's records list 3 violations for this system; 1 is health-based, and the most recent began in April 2008. The violations listed here began between July 1998 and April 2008. By type: 2 monitoring and reporting and 1 contaminant level above the legal limit. The contaminants or rules involved are Benzene, Nitrate and Total coliform bacteria (TCR). EPA lists 3 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 |
|---|---|---|---|---|
| 2008-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | Resolved |
| 2006-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1998-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
All 3 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.
Downtown Graton Mutual Water System: frequently asked questions
Who runs Downtown Graton Mutual Water System?
Downtown Graton Mutual Water System (PWSID CA4901246) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Downtown Graton Mutual Water System serve?
Downtown Graton Mutual Water System reports serving 115 people through 28 service connections in Sonoma County, California.
Where does Downtown Graton Mutual Water System 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 Downtown Graton Mutual Water System have any drinking water violations?
EPA's records list 3 violations for this system; 1 is health-based, and the most recent began in April 2008. 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 Downtown Graton Mutual Water System'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 3 violations for this system; 1 is health-based, and the most recent began in April 2008. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Downtown Graton Mutual Water System's water quality report?
As a community water system, Downtown Graton Mutual Water System 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 |
| 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 |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, “Downtown Graton Mutual Water System, PWSID CA4901246, California”, https://aquacensus.com/water-systems/california/downtown-graton-mutual-water-system-ca4901246 (data as of October 1, 2026).