District of Columbia Water Quality Ratings

TapWaterSafety has rated 2 public water systems in District of Columbia, serving a combined 1,337,323 residents. The statewide average grade is D.

Data sources: EPA SDWIS EPA ECHO EWG Tap Water Database Utility CCRs ⓘ How did we get these ratings?
State average grade
D
64/100
Total utilities rated 2
Population served 1,337,323
Most recent test 2024
🇪🇺 Would fail EU standards 1 of 2

Top water quality concerns in District of Columbia

  • Haloacetic acids (HAA9) significantly above health guideline
  • Haloacetic acids (HAA5) significantly above health guideline
  • Total trihalomethanes (TTHMs) significantly above health guideline
  • Arsenic detected
  • Lead detected in source water

Cities in District of Columbia

Browse tap water quality reports by city. Click any city to see its grade, what's in the water, and recommended filters.

WASHINGTON
D 632,323
Washington
D 705,000

Grade distribution

A
0 (0%)
B
0 (0%)
C
1 (50%)
D
1 (50%)
F
0 (0%)

All rated utilities in District of Columbia

Sorted by score, highest first. Click any utility to see the full grade card.

Rank Utility City Population Score Grade
#1 Washington Municipal Water System Washington 705,000 66 C
#2 D.C. WATER AND SEWER AUTHORITY WASHINGTON 632,323 63 D