County Water Quality Report

District of Columbia County, District of Columbia

2 public water systems serving 1,337,323 residents

Data sources: EPA SDWIS EPA ECHO EWG Tap Water Database Utility CCRs ⓘ How did we get these ratings?
County average grade
D
64/100
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 County

  • Haloacetic acids (HAA9) significantly above health guidelinein 1 of 2 utilities
  • Haloacetic acids (HAA5) significantly above health guidelinein 1 of 2 utilities
  • Total trihalomethanes (TTHMs) significantly above health guidelinein 1 of 2 utilities
  • Arsenic detectedin 1 of 2 utilities
  • Lead detected in source waterin 1 of 2 utilities

All utilities in District of Columbia County

Click any utility for full grade card, contaminant data, and treatment plant contact info.

C
66/100

Washington Municipal Water System

Washington · 705,000 residents

Top concern: Lead detected in source water

View report →
D
63/100

D.C. WATER AND SEWER AUTHORITY

WASHINGTON · 632,323 residents

Top concern: Haloacetic acids (HAA9) significantly above health guideline

View report →