SONOMA, CITY OF
California — Community Water System — PWSID: CA4910012
System Information
| PWSID | CA4910012 |
| System Name | SONOMA, CITY OF |
| System Type | Community Water System |
| Water Source | Ground Water |
| Activity Status | Active |
| Owner Type | Local |
| EPA Region | 09 |
| Serves School | No |
| Wholesaler | No |
| First Reported | Mar 22, 1979 |
| Last Reported | Mar 20, 2026 |
Location & Contact
| State | California |
| City | SONOMA |
| ZIP Code | 95476 |
| Address | No, 1 The Plaza |
| Organization | BERGER, MIKE |
| Phone | 707-933-2230 |
Population & Service
| Population Served | 11,725 |
| Service Connections | 4,343 |
Drinking Water Violations (17)
This water system has 17 violations recorded in the EPA SDWIS database.
| Begin Date | End Date | Contaminant | Category | Health-Based | Major | Measured | Federal MCL | State MCL | Status | Return to Compliance | Rule |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Jul 2, 2025 | — | RPT | No | No | — | — | — | Unaddressed | — | — | |
| Apr 1, 2021 | Jun 30, 2021 | MR | No | Yes | — | 0.010 mg/L | — | Resolved | Jun 30, 2021 | — | |
| Apr 1, 2021 | Jun 30, 2021 | MR | No | Yes | — | 0.010 mg/L | — | Resolved | Jun 30, 2021 | — | |
| Jan 1, 2020 | Dec 31, 2020 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2020 | — | |
| Jan 1, 2020 | Dec 31, 2020 | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2020 | — | |
| Jan 1, 2020 | Dec 31, 2020 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2020 | — | |
| Jan 1, 2020 | Dec 31, 2020 | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2020 | — | |
| Nov 1, 2017 | Nov 30, 2017 | MON | No | No | — | — | — | Resolved | Nov 30, 2017 | — | |
| Nov 1, 2017 | Nov 30, 2017 | MON | No | No | — | — | — | Resolved | Nov 30, 2017 | — | |
| Jan 1, 2010 | Jan 31, 2010 | MCL | Yes | No | — | 5% of samples | — | Resolved | Jan 31, 2010 | — | |
| Jan 1, 2010 | Jan 31, 2010 | MCL | Yes | No | — | 5% of samples | — | Resolved | Jan 31, 2010 | — | |
| Apr 1, 2006 | Jun 30, 2006 | MR | No | No | — | 0.060 mg/L | — | Resolved | Jun 30, 2006 | — | |
| Apr 1, 2006 | Jun 30, 2006 | MR | No | No | — | 0.060 mg/L | — | Resolved | Jun 30, 2006 | — | |
| Apr 1, 2006 | Jun 30, 2006 | MR | No | No | — | 0.080 mg/L | — | Resolved | Jun 30, 2006 | — | |
| Apr 1, 2006 | Jun 30, 2006 | MR | No | No | — | 0.080 mg/L | — | Resolved | Jun 30, 2006 | — | |
| Jan 1, 2006 | Dec 31, 2006 | MR | No | Yes | — | 10 mg/L | — | Resolved | Dec 31, 2006 | — | |
| Jan 1, 2006 | Dec 31, 2006 | MR | No | Yes | — | 10 mg/L | — | Resolved | Dec 31, 2006 | — |
About This Water System
Public water system data comes from the EPA Safe Drinking Water Information System (SDWIS). Systems with violations must notify customers. Contact your water utility for the latest annual water quality report.