Is District of Columbia tap water safe? What the EPA data shows
The EPA’s national PFAS monitoring round (UCMR5) produced a full set of results for only 3 water systems in District of Columbia — too few to state a reliable statewide rate. Nationally, 11.4% of systems with a full set averaged PFOA or PFOS above the EPA’s 4 ppt limit. For District of Columbia, the honest answer is: check your specific utility.
Check what your specific utility reported for YOUR ZIP code, and the exact filter that handles it: Check your water by ZIP →
Which PFAS show up most in District of Columbia
- PFHxA (3 systems)
- PFPeA (3 systems)
Common questions about District of Columbia water
Is District of Columbia's tap water safe to drink?
Only 3 District of Columbia systems reported a full set of results in the EPA’s PFAS monitoring round, too few for a reliable statewide answer — check your own utility. These are system-level records for public water systems, not a reading of any individual home’s tap, and they do not cover private wells. Confirm your own utility’s current Consumer Confidence Report, and test your tap if you’re unsure.
Does District of Columbia have PFAS in its drinking water?
No District of Columbia system in the EPA’s UCMR5 monitoring averaged PFOA or PFOS above the 4 ppt limit — though some PFAS compounds were detected. Rates are over the water systems that reported a FULL set of UCMR5 results in this state (the only ones EPA’s method can average) — not all systems, and not population. A state that tested more systems can show more detections simply because it looked harder.
How do I check my specific District of Columbia water system?
Enter your ZIP on the water checker to see what YOUR utility reported and the filter that handles it.
Neighboring states
See the full 50-state water-quality index and the national PFAS data study.
Rates are over the water systems that reported a FULL set of UCMR5 results in this state (the only ones EPA’s method can average) — not all systems, and not population. A state that tested more systems can show more detections simply because it looked harder.
Sources: EPA UCMR5 occurrence data, Feb 2026 release (~95% complete; final reporting 2026) (2026-06), public domain; beyond-PFAS: EPA Six-Year Review (SYR4, compliance monitoring 2012-2019) + current state Drinking Water Watch (CA, FL). Computed by scripts/build_state_water_data.py. Built 2026-07-25. Every figure is traceable to the committed EPA data.