District of Columbia tap water by county
Hardness, PFAS sampling, lead and violations for the largest water systems in 1 District of Columbia county. In 1 of them, at least one large system detected PFAS in EPA testing (a detection isn't a violation).
| County | Largest system | Hardness | PFAS detected |
|---|---|---|---|
| District of Columbia | D.C. Water and Sewer Authority | 8.1 gpg (high) | 3 of 3 systems |
Public-record figures, not a test of your tap. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
Hardness confidence: high = utility report; low = county estimate of untreated local water. Don't see your county? Use the water quality lookup.