TERWILLIGER ASSOCIATION
California — Transient Non-Community — PWSID: CA3301146
System Information
| PWSID | CA3301146 |
| System Name | TERWILLIGER ASSOCIATION |
| System Type | Transient Non-Community |
| 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 | Nov 17, 2025 |
Location & Contact
| State | California |
| City | ANZA |
| ZIP Code | 92539 |
| Address | PO Box 390433 |
| Organization | ASHBY, ANNIE |
| Phone | 760-519-6062 |
Population & Service
| Population Served | 2,401 |
| Service Connections | 2 |
Drinking Water Violations (13)
This water system has 13 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Jan 1, 2021 | Mar 31, 2021 | Revised Total Coliform Rule | MON | No | Yes | — | — | — | Resolved | Mar 31, 2021 | Revised Total Coliform Rule |
| Jan 1, 2021 | Mar 31, 2021 | Revised Total Coliform Rule | MON | No | Yes | — | — | — | Resolved | Mar 31, 2021 | Revised Total Coliform Rule |
| Mar 1, 2016 | Apr 30, 2016 | Coliform (TCR) | MCL | Yes | No | — | 5% of samples | — | Resolved | Apr 30, 2016 | Total Coliform Rule |
| Mar 1, 2016 | Apr 30, 2016 | Coliform (TCR) | MCL | Yes | No | — | 5% of samples | — | Resolved | Apr 30, 2016 | Total Coliform Rule |
| Mar 1, 2016 | Apr 30, 2016 | Coliform (TCR) | MCL | Yes | No | — | 5% of samples | — | Resolved | Apr 30, 2016 | Total Coliform Rule |
| Aug 1, 2015 | Aug 31, 2015 | Coliform (TCR) | MCL | Yes | No | — | 5% of samples | — | Resolved | Aug 31, 2015 | Total Coliform Rule |
| Aug 1, 2015 | Aug 31, 2015 | Coliform (TCR) | MCL | Yes | No | — | 5% of samples | — | Resolved | Aug 31, 2015 | Total Coliform Rule |
| Jan 1, 2014 | Dec 31, 2016 | Nitrite | MR | No | Yes | — | 1 mg/L | — | Resolved | Dec 31, 2016 | Nitrate Rule |
| Jan 1, 2014 | Dec 31, 2016 | Nitrite | MR | No | Yes | — | 1 mg/L | — | Resolved | Dec 31, 2016 | Nitrate Rule |
| Dec 1, 1983 | Dec 31, 1983 | Other | No | No | — | — | — | Archived | Dec 31, 1983 | Miscellaneous Other Rules | |
| Mar 1, 1983 | Mar 31, 1983 | Other | No | No | — | — | — | Archived | Mar 31, 1983 | Miscellaneous Other Rules | |
| Feb 1, 1983 | Feb 28, 1983 | Other | No | No | — | — | — | Archived | Feb 28, 1983 | Miscellaneous Other Rules | |
| Jan 1, 1983 | Jan 31, 1983 | Other | No | No | — | — | — | Archived | Jan 31, 1983 | Miscellaneous Other Rules |
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.