Public water system · CA4901112
ActiveLake Sonoma Marina
At a glance
Lake Sonoma Marina (PWSID CA4901112) is an active transient non-community water system in Sonoma County, California. It reports serving 51 people through 2 service connections. Its primary water source is surface water, and EPA lists it as privately owned. EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in August 1997.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
51
Service connections
2
Primary source
SW
Surface water
System type
TNCWS
Transient non-community water system
System record
How does Lake Sonoma Marina compare with other water systems in Sonoma County?
By EPA's size categories, Lake Sonoma Marina 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 Lake Sonoma Marina is about 65% 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. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 609 California systems (8.1%) list surface water as their primary source.
Who owns and regulates Lake Sonoma Marina?
EPA lists Lake Sonoma Marina 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 Lake Sonoma Marina have drinking water violations?
EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in August 1997. The violations listed here began between March 1994 and August 1997. By type: 3 required treatment not met and 2 monitoring and reporting. The contaminant or rule involved most often is Surface Water Treatment Rule (3 of them). EPA lists 5 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 |
|---|---|---|---|---|
| 1997-08-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1995-07-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1994-11-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Surface Water Treatment Rulecode 0200 | Yes | Resolved |
| 1994-09-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Surface Water Treatment Rulecode 0200 | Yes | Resolved |
| 1994-03-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Surface Water Treatment Rulecode 0200 | Yes | Resolved |
All 5 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.
Lake Sonoma Marina: frequently asked questions
Who runs Lake Sonoma Marina?
Lake Sonoma Marina (PWSID CA4901112) is a transient non-community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Lake Sonoma Marina serve?
Lake Sonoma Marina reports serving 51 people through 2 service connections in Sonoma County, California.
Where does Lake Sonoma Marina get its water?
EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.
Does Lake Sonoma Marina have any drinking water violations?
EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in August 1997. 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 Lake Sonoma Marina'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 5 violations for this system; 3 are health-based, and the most recent began in August 1997. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Lake Sonoma Marina's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Lake Sonoma Marina 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, “Lake Sonoma Marina, PWSID CA4901112, California”, https://aquacensus.com/water-systems/california/lake-sonoma-marina-ca4901112 (data as of October 1, 2026).