COASTSIDE COUNTY WATER DISTRICT
California - Community Water System - PWSID: CA4110011
System Information
| PWSID | CA4110011 |
| System Name | COASTSIDE COUNTY WATER DISTRICT |
| System Type | Community Water System |
| Water Source | Surface 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 | HALF MOON BAY |
| ZIP Code | 94019 |
| Address | 766 Main Street |
| Organization | ROGREN, MARY |
| Phone | 650-276-0889 |
Population & Service
| Population Served | 18,940 |
| Service Connections | 6,617 |
Drinking Water Violations (33)
This water system has 33 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Apr 1, 2008 | Apr 30, 2008 | TT | Yes | No | - | - | - | Resolved | Apr 30, 2008 | - | |
| Apr 1, 2008 | Apr 30, 2008 | TT | Yes | No | - | - | - | Resolved | Apr 30, 2008 | - | |
| Jun 1, 2005 | Jun 30, 2005 | TT | Yes | No | - | - | - | Resolved | Jun 30, 2005 | - | |
| Jun 1, 2005 | Jun 30, 2005 | TT | Yes | No | - | - | - | Resolved | Jun 30, 2005 | - | |
| Feb 1, 2005 | Feb 28, 2005 | MR | No | No | - | - | - | Resolved | Feb 28, 2005 | - | |
| Jan 1, 2004 | Jan 31, 2004 | MCL | Yes | No | - | 5% of samples | - | Resolved | Jan 31, 2004 | - | |
| Jan 1, 2004 | Jan 31, 2004 | MCL | Yes | No | - | 5% of samples | - | Resolved | Jan 31, 2004 | - | |
| Jul 1, 2003 | Jul 31, 2003 | MR | No | No | - | 5% of samples | - | Resolved | Jul 31, 2003 | - | |
| Jul 1, 2003 | Jul 31, 2003 | MR | No | No | - | 5% of samples | - | Resolved | Jul 31, 2003 | - | |
| Jan 1, 2002 | Jan 31, 2002 | MCL | Yes | No | - | 5% of samples | - | Resolved | Jan 31, 2002 | - | |
| Jan 1, 2002 | Jan 31, 2002 | MCL | Yes | No | - | 5% of samples | - | Resolved | Jan 31, 2002 | - | |
| Jan 1, 2002 | Jan 31, 2002 | MCL | Yes | No | - | 5% of samples | - | Resolved | Jan 31, 2002 | - | |
| Jan 1, 2002 | Jan 31, 2002 | MCL | Yes | No | - | 5% of samples | - | Resolved | Jan 31, 2002 | - | |
| Oct 1, 2001 | Dec 31, 2001 | MR | No | No | - | 10 mg/L | - | Resolved | Dec 31, 2001 | - | |
| Oct 1, 2001 | Dec 31, 2001 | MR | No | No | - | 10 mg/L | - | Resolved | Dec 31, 2001 | - | |
| Oct 1, 2001 | Dec 31, 2001 | MR | No | No | - | 10 mg/L | - | Resolved | Dec 31, 2001 | - | |
| Oct 1, 2001 | Dec 31, 2001 | MR | No | No | - | 10 mg/L | - | Resolved | Dec 31, 2001 | - | |
| Jul 1, 2001 | Sep 30, 2001 | MR | No | No | - | 10 mg/L | - | Resolved | Sep 30, 2001 | - | |
| Jul 1, 2001 | Sep 30, 2001 | MR | No | No | - | 10 mg/L | - | Resolved | Sep 30, 2001 | - | |
| Jul 1, 2001 | Sep 30, 2001 | MR | No | No | - | 10 mg/L | - | Resolved | Sep 30, 2001 | - | |
| Jul 1, 2001 | Sep 30, 2001 | MR | No | No | - | 10 mg/L | - | Resolved | Sep 30, 2001 | - | |
| Nov 1, 1998 | Nov 30, 1998 | MCL | Yes | No | - | 5% of samples | - | Resolved | Nov 30, 1998 | - | |
| Nov 1, 1998 | Nov 30, 1998 | MCL | Yes | No | - | 5% of samples | - | Resolved | Nov 30, 1998 | - | |
| Feb 7, 1996 | Mar 31, 1996 | Other | No | No | - | 5% of samples | - | Resolved | Mar 31, 1996 | - | |
| Feb 7, 1996 | Mar 31, 1996 | Other | No | No | - | 5% of samples | - | Resolved | Mar 31, 1996 | - | |
| Feb 1, 1996 | Feb 29, 1996 | MCL | Yes | No | - | 5% of samples | - | Resolved | Feb 29, 1996 | - | |
| Feb 1, 1996 | Mar 31, 1996 | MR | No | No | - | 5% of samples | - | Resolved | Mar 31, 1996 | - | |
| Feb 1, 1996 | Mar 31, 1996 | MR | No | No | - | 5% of samples | - | Resolved | Mar 31, 1996 | - | |
| Feb 1, 1996 | Feb 29, 1996 | MCL | Yes | No | - | 5% of samples | - | Resolved | Feb 29, 1996 | - | |
| Jun 30, 1993 | Apr 4, 2000 | MR | No | No | - | TT | - | Resolved | Apr 4, 2000 | - | |
| Jun 1, 1992 | Jul 31, 1992 | MR | No | No | - | 5% of samples | - | Resolved | Jul 31, 1992 | - | |
| Jun 1, 1992 | Jul 31, 1992 | MR | No | No | - | 5% of samples | - | Resolved | Jul 31, 1992 | - | |
| - | - | - | No | No | - | - | - | - | - | - |
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.