We found 9 public water systems in District of Columbia county (ordered by population size).
| Name | Areas served | Population served | Contaminant count | Violation count |
|---|---|---|---|---|
| D.c. Water And Sewer Authority | Washington | 632,323 | 68 | 29 |
| Naval Station Washington - Wny | Washington Navy Yard | 15,690 | 32 | 17 |
| Bolling - Joint Base Anacostia-bolling | Washington | 12,499 | 31 | 19 |
| Anacostia - Joint Base Anacostia-bolling | County of District Of Columbia | 4,060 | 0 | 9 |
| Hubert H. Humphrey Building | County of District Of Columbia | 1,400 | 0 | 0 |
| Nebraska Avenue Complex (nav Dist Wash) | County of District Of Columbia | 1,100 | 0 | 0 |
| Mandarin Oriental Hotel | County of District Of Columbia | 780 | 0 | 5 |
| Naval Observatory | County of District Of Columbia | 250 | 0 | 10 |
| Washington Aqueduct Division | County of District Of Columbia | 0 | 0 | 0 |