Public water system · CA4901090
ActivePreston Winery
At a glance
Preston Winery (PWSID CA4901090) is an active transient non-community water system in Sonoma County, California. It reports serving 55 people through 1 service connection. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 4 violations for this system; none is health-based, and the most recent began in June 2017.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
55
Service connections
1
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Preston Winery compare with other water systems in Sonoma County?
By EPA's size categories, Preston Winery 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 transient non-community water system reports serving 144 people, so Preston Winery is about 62% below that figure.
What does “transient non-community water system” mean?
A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. California has 3,016 active transient non-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 Preston Winery?
EPA lists Preston Winery 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 Preston Winery have drinking water violations?
EPA's records list 4 violations for this system; none is health-based, and the most recent began in June 2017. The violations listed here began between April 1995 and June 2017. By type: 3 monitoring and reporting and 1 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (3 of them). EPA lists 4 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 |
|---|---|---|---|---|
| 2017-06-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2000-03-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1998-03-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1995-04-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
All 4 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.
Preston Winery: frequently asked questions
Who runs Preston Winery?
Preston Winery (PWSID CA4901090) is a transient non-community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Preston Winery serve?
Preston Winery reports serving 55 people through 1 service connection in Sonoma County, California.
Where does Preston Winery 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 Preston Winery have any drinking water violations?
EPA's records list 4 violations for this system; none is health-based, and the most recent began in June 2017. 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 Preston Winery'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 4 violations for this system; none is health-based, and the most recent began in June 2017. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Preston Winery's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Preston Winery is a transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
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, “Preston Winery, PWSID CA4901090, California”, https://aquacensus.com/water-systems/california/preston-winery-ca4901090 (data as of October 1, 2026).