We found 18 public water systems that could serve the same population as Fairfield Union High School (ordered by population size).
| Name | Areas served | Population served | Contaminant count | Violation count |
|---|---|---|---|---|
| Lancaster City Pws | Lancaster | 40,400 | 13 | 2 |
| Colonial Estates Mhp-south | Lancaster | 400 | 0 | 0 |
| Colonial Estates Mhp-north | Lancaster | 350 | 0 | 0 |
| Riviera Cabinets Inc | Lancaster | 120 | 0 | 0 |
| Grace Lutheran Church | Lancaster | 100 | 0 | 0 |
| Starrett Aviation | Lancaster | 95 | 0 | 0 |
| South Central Power Co Pws | Lancaster | 75 | 0 | 0 |
| Rushville Lions Club | Lancaster | 75 | 0 | 0 |
| Premium Glass Company, Inc. | Lancaster | 68 | 0 | 0 |
| Lancaster Mould Company | Lancaster | 65 | 0 | 0 |
| Lancaster Mould Company | Lancaster | 65 | 0 | 0 |
| Cranberry Mobile Home Park | Lancaster | 48 | 0 | 0 |
| Happy Homes Realty | Lancaster | 45 | 0 | 0 |
| Kent A Guisinger Do Pws | Lancaster | 34 | 0 | 0 |
| Old Schoolhouse Family Practice Pws | Lancaster | 33 | 0 | 0 |
| Charles Alley Park-residence Pws | Lancaster | 30 | 0 | 0 |
| Whok Radio Station | Lancaster | 30 | 0 | 0 |
| Roxy's Island Pws | Lancaster | 15 | 0 | 0 |