Public water system · CA2110003
ActiveNorth Marin Water District
At a glance
North Marin Water District (PWSID CA2110003) is an active community water system in Marin County, California. It reports serving 61,691 people through 20,438 service connections. Its primary water source is surface water, and EPA lists it as owned by a local government. EPA's records list one violation for this system; it is health-based, and the most recent began in July 1993.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
61,691
Service connections
20,438
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does North Marin Water District compare with other water systems in Marin County?
By EPA's size categories, North Marin Water District is a large system (10,001 to 100,000 people). Marin County has 46 active public water systems, and North Marin Water District is the 2nd-largest of them by population served. Its population served is about 9.9 times the county average of 6,203 people per system, and accounts for 22% of the 285,353 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 North Marin Water District is about 9.2 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. 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 North Marin Water District?
EPA lists North Marin Water District 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. 12 of the 46 active systems in Marin County (26%) are also owned by a local government.
Does North Marin Water District have drinking water violations?
EPA's records list one violation for this system; it is health-based, and the most recent began in July 1993. By type: 1 contaminant level above the legal limit. The contaminant or rule involved is Total coliform bacteria (TCR). EPA lists 1 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 |
|---|---|---|---|---|
| 1993-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
The one violation in EPA's records.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.
North Marin Water District: frequently asked questions
Who runs North Marin Water District?
North Marin Water District (PWSID CA2110003) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does North Marin Water District serve?
North Marin Water District reports serving 61,691 people through 20,438 service connections in Marin County, California.
Where does North Marin Water District 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 North Marin Water District have any drinking water violations?
EPA's records list one violation for this system; it is health-based, and the most recent began in July 1993. 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 North Marin Water District'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 one violation for this system; it is health-based, and the most recent began in July 1993. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find North Marin Water District's water quality report?
As a community water system, North Marin Water District 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 Marin County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Marin Municipal Water District | Marin | 186,895 | Community | Surface water |
| Nps Ggnra | Marin | 18,447 | Community | Purchased surface water |
| Bolinas Community PUD | Marin | 2,483 | Community | Surface water |
| North Marin Wd - Pt. Reyes | Marin | 1,841 | Community | Groundwater |
| Csp - Angel Island St Park | Marin | 1,622 | Transient non-community | Groundwater |
| Nps Prns - Beaches | Marin | 1,560 | 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, “North Marin Water District, PWSID CA2110003, California”, https://aquacensus.com/water-systems/california/north-marin-water-district-ca2110003 (data as of October 1, 2026).