Surface Water Treatment Rule (SWTR) violations in California
56 active public water systems in California had a Surface Water Treatment Rule (SWTR) violation in the past three years, 28 of them in the latest quarter of EPA's data. What Surface Water Treatment Rule (SWTR) is and why it matters.
Systems with a Surface Water Treatment Rule (SWTR) violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
John Hovannisian Water System Madera County |
80 | 8 | 1 | |
|
Portola Improvement Association Mwc San Mateo County |
80 | 1 | 0 | |
|
Valley Mobile Home Park Imperial County |
70 | 3 | 1 | |
|
River Grove Mutual Water Assn Santa Cruz County |
54 | 3 | 0 | |
|
Indian Creek Trailer Park Trinity County |
41 | 2 | 1 | |
|
Camp Loma Mar San Mateo County |
25 | 2 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved Surface Water Treatment Rule (SWTR), including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Surface Water Treatment Rule (SWTR) alone.
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.