California
Yolo County drinking water quality
88 active public water systems serve 224,609 people in Yolo County. 56 are compliant, 32 had at least one EPA violation in the past three years, 0 are designated serious violators, and 11 carry a health flag.
Needs attention
1 more systems with a serious violator or health flag designation are in the lists below.
Community water systems
16 systems, largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
City of Davis Davis |
67,826 | 0 | 0 | |
|
City of Woodland Woodland |
61,462 | 0 | 0 | |
|
City of West Sacramento West Sacramento |
55,991 | 1 | 1 | |
|
UC Davis |
13,177 | 1 | 0 | |
|
City of Winters Winters |
7,115 | 0 | 0 | |
|
Esparto C.s.d. |
3,572 | 0 | 0 | |
|
Wild Wings Golf Community |
1,115 | 0 | 0 | |
|
Knights Landing Svc. Dist. |
1,099 | 1 | 1 | |
|
Madison Service Dist |
876 | 8 | 1 | |
|
Cal AM Dunnigan |
602 | 0 | 0 | |
|
Yolo CO Housing Authority-El Rio Villa |
432 | 0 | 0 | |
|
Cacheville Service Dist |
239 | 8 | 1 | |
|
Campers Inn RV & Golf Course |
95 | 1 | 0 | |
|
Rolling Acres Mutual Water Company |
40 | 0 | 0 | |
|
Bonfire Village Hotel |
25 | 1 | 0 | |
|
Woodland-Davis Clean Water Agency Woodland |
0 | 0 | 0 |
Non-community systems (72: schools, campgrounds, workplaces, restaurants)
These systems serve places people visit rather than homes.
Inactive systems (133, 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.