California
Marin County drinking water quality
47 active public water systems serve 266,457 people in Marin County. 44 are compliant, 3 had at least one EPA violation in the past three years, 0 are designated serious violators, and 2 carry a health flag.
Needs attention
Community water systems
14 systems, largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Marin Municipal Water District |
188,116 | 0 | 0 | |
|
North Marin Water District |
61,691 | 0 | 0 | |
|
Bolinas Community Pud |
1,937 | 0 | 0 | |
|
North Marin WD Pt. Reyes |
1,841 | 0 | 0 | |
|
Inverness Public Utility Dist |
1,445 | 1 | 1 | |
|
Lawson S Landing |
946 | 0 | 0 | |
|
Stinson Beach County Wtr Dist |
583 | 0 | 0 | |
|
Coast Springs Cal. Water Service (puc) |
445 | 0 | 0 | |
|
Muir Beach Community |
336 | 0 | 0 | |
|
Estero Mutual |
206 | 0 | 0 | |
|
Green Gulch Farm |
75 | 1 | 1 | |
|
Nps Ggnra |
75 | 0 | 0 | |
|
Nicasio Valley Ranch Mutual |
36 | 0 | 0 | |
|
Blue Mountain Center |
25 | 0 | 0 |
Non-community systems (33: schools, campgrounds, workplaces, restaurants)
These systems serve places people visit rather than homes.
Inactive systems (56, no longer operating or reporting)
Kept for the record and excluded from the county totals above. Browse inactive systems.
About this data
Totals cover active systems. Systems serving more than one county are counted in each county. EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The California records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.