COUNTY WATER-SYSTEM LEDGER
San Luis Obispo, California
EPA’s September 2026 export lists 20 active community water systems serving San Luis Obispo, California, with 0 current-violation flags and 0 serious-violator flags among the covered systems.
Source: EPA SDWIS system-search export · Active community systems serving 2,500+ people · Snapshot 13 Sep 2026
01 / SYSTEMS
Water systems serving San Luis Obispo, California
EPA associates 20 covered systems with San Luis Obispo, California; their reported population-served values total 245,555 and may overlap.
Ordered by reported population served. Open any record for separate health, monitoring, notice, other, and serious-violator flags.
| Water system | Population served | Primary source | Current export status |
|---|---|---|---|
| San Luis Obispo Water DepartmentCA4010009 | 47,788 | Surface water | No current violation flagged |
| City Of Paso Robles Water DivisionCA4010007 | 31,176 | Surface water | No current violation flagged |
| Atascadero Mutual Water CoCA4010002 | 30,618 | Ground water | No current violation flagged |
| City Of Arroyo Grande Utilities DivisionCA4010001 | 17,963 | Surface water purchased | No current violation flagged |
| California Mens ColonyCA4010830 | 15,000 | Surface water | No current violation flagged |
| Nipomo Comm Services DistCA4010026 | 13,771 | Surface water purchased | No current violation flagged |
| Morro Bay Pw Dept - Water DivisionCA4010011 | 13,757 | Surface water purchased | No current violation flagged |
| City Of Grover Beach Public Works DeptCA4010004 | 12,701 | Surface water | No current violation flagged |
| Pismo Beach Water DepartmentCA4010008 | 8,036 | Surface water purchased | No current violation flagged |
| Templeton CsdCA4010019 | 8,011 | Ground water | No current violation flagged |
| Oceano Comm Services Dist.CA4010005 | 7,601 | Surface water purchased | No current violation flagged |
| Los Osos Community Services DistrictCA4010016 | 7,086 | Ground water | No current violation flagged |
| Golden State Water Company - Los OsosCA4010017 | 5,924 | Ground water | No current violation flagged |
| Cambria Comm Services DistCA4010014 | 5,532 | Ground water | No current violation flagged |
| Golden State Water Company - NipomoCA4010018 | 4,506 | Surface water purchased | No current violation flagged |
| Atascadero State HospitalCA4010832 | 4,100 | Ground water | No current violation flagged |
| Woodlands DevelopmentCA4010081 | 3,862 | Surface water purchased | No current violation flagged |
| Heritage Ranch CsdCA4010012 | 2,956 | Surface water | No current violation flagged |
| San Miguel Community Services DistrictCA4010010 | 2,600 | Ground water | No current violation flagged |
| Cayucos Beach Mutual Water CompanyCA4010006 | 2,567 | Surface water purchased | No current violation flagged |
02 / SOURCE MIX
Primary water sources for San Luis Obispo, California
EPA classifies 20 systems serving San Luis Obispo, California across 3 primary-source categories; Surface water is the largest category with 5 systems.
It is the sum of each listed system's reported population served, not a census estimate. Service areas can overlap and some systems list multiple cities or counties.