MISSION HIGHLANDS MUTUAL WATER CO.
California - Community Water System - PWSID: CA4900563
System Information
| PWSID | CA4900563 |
| System Name | MISSION HIGHLANDS MUTUAL WATER CO. |
| System Type | Community Water System |
| Water Source | Ground Water |
| Activity Status | Active |
| Owner Type | Private |
| 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 | 17240 High Road |
| Organization | JOHNSTON, TOPPER |
| Phone | 415-710-8629 |
Population & Service
| Population Served | 150 |
| Service Connections | 69 |
Drinking Water Violations (16)
This water system has 16 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| May 1, 2021 | May 31, 2021 | MON | No | Yes | - | - | - | Resolved | May 31, 2021 | - | |
| May 1, 2021 | May 31, 2021 | MON | No | Yes | - | - | - | Resolved | May 31, 2021 | - | |
| Oct 1, 2019 | - | MR | No | No | - | TT | - | Resolved | Jun 1, 2020 | - | |
| Oct 1, 2019 | - | MR | No | No | - | TT | - | Resolved | Jun 1, 2020 | - | |
| Oct 1, 2019 | - | MR | No | No | - | TT | - | Resolved | Jun 1, 2020 | - | |
| Jan 1, 2019 | Dec 31, 2021 | MR | No | Yes | - | 0.080 mg/L | - | Resolved | Dec 31, 2021 | - | |
| Jan 1, 2019 | Dec 31, 2021 | MR | No | Yes | - | 0.080 mg/L | - | Resolved | Dec 31, 2021 | - | |
| Jan 1, 2019 | Dec 31, 2021 | MR | No | Yes | - | 0.060 mg/L | - | Resolved | Dec 31, 2021 | - | |
| Jan 1, 2019 | Dec 31, 2021 | MR | No | Yes | - | 0.060 mg/L | - | Resolved | Dec 31, 2021 | - | |
| Jul 1, 2001 | Jul 31, 2001 | MCL | Yes | No | - | 5% of samples | - | Resolved | Jul 31, 2001 | - | |
| Jul 1, 2001 | Jul 31, 2001 | MCL | Yes | No | - | 5% of samples | - | Resolved | Jul 31, 2001 | - | |
| Sep 1, 1984 | Sep 30, 1984 | Other | No | No | - | - | - | Archived | Sep 30, 1984 | - | |
| Jul 1, 1984 | Jul 31, 1984 | Other | No | No | - | - | - | Archived | Jul 31, 1984 | - | |
| Oct 1, 1982 | Oct 31, 1982 | Other | No | No | - | - | - | Archived | Oct 31, 1982 | - | |
| Oct 1, 1981 | Sep 30, 1982 | MR | No | Yes | - | 15 pCi/L | - | Archived | Sep 30, 1982 | - | |
| Oct 30, 1980 | Oct 29, 1981 | MR | No | Yes | - | 15 pCi/L | - | Archived | Oct 29, 1981 | - |
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.