District of Columbia Tap Water Quality Report
2 cities analyzed • 648,013 people served
Updated April 2026 • Data from EWG & EPA SDWIS
Most Common Contaminants in District of Columbia
| Contaminant | Found In | % of Cities |
|---|---|---|
| Chromium (hexavalent) carcinogen | 2 of 2 | 100% |
| Haloacetic acids (HAA5) carcinogen | 2 of 2 | 100% |
| Haloacetic acids (HAA9) carcinogen | 2 of 2 | 100% |
| Nitrate carcinogen | 2 of 2 | 100% |
| Total trihalomethanes (TTHMs) carcinogen | 2 of 2 | 100% |
| Chlorate | 2 of 2 | 100% |
| Manganese | 2 of 2 | 100% |
| Perfluorohexanoic Acid (PFHxA) | 2 of 2 | 100% |
| Perfluoropentanoic Acid (PFPeA) | 2 of 2 | 100% |
| Strontium | 2 of 2 | 100% |
City-by-City Water Quality Rankings
Ranked by number of contaminants above EWG health guidelines (most to fewest).
| # | City | Detected | Above Guidelines | Above Legal | People Served |
|---|---|---|---|---|---|
| 1 | Washington | 37 | 14 | 0 | 632,323 |
| 2 | Washington Navy Yard | 26 | 12 | 0 | 15,690 |
Recommended Filtration for District of Columbia
Based on the most common contaminants found across District of Columbia (Chromium (hexavalent), Haloacetic acids (HAA5), Haloacetic acids (HAA9)), we recommend a reverse osmosis (RO) system — the only technology proven to remove heavy metals, PFAS, and most other contaminants to safe levels.
Echo RO System
Removes up to 99.9% of contaminants. The gold standard for drinking water in District of Columbia homes.
View RO SystemsEcho Whole-Home Filter
Protect every tap in your home from chlorine, VOCs, and disinfection byproducts.
View Whole-Home FiltersEcho Hydrogen Water Flask
Once your water is clean, supercharge it with molecular hydrogen for antioxidant and anti-inflammatory benefits.
Shop Hydrogen FlaskFrequently Asked Questions
Is District of Columbia tap water safe to drink?
Water quality varies significantly across District of Columbia. Of the 2 cities analyzed, the average city has 13.0 contaminants above EWG health guidelines. The best water quality was found in Washington Navy Yard. We recommend checking your specific city's report for detailed information.
What city has the best water in District of Columbia?
Based on our analysis, Washington Navy Yard has the fewest contaminants above EWG health guidelines in District of Columbia, with 12 above guideline levels.
What city has the worst water in District of Columbia?
Based on our analysis, Washington has the most contaminants above EWG health guidelines in District of Columbia, with 14 above guideline levels.
What's the best water filter for District of Columbia residents?
For most District of Columbia households, we recommend a reverse osmosis (RO) system for drinking water and a whole-home filter for showers and baths. The specific recommendation depends on your city's contaminant profile — check your city's report for personalized guidance.
National Water Quality Reports
Data sources: Environmental Working Group (EWG) Tap Water Database, U.S. EPA Safe Drinking Water Information System (SDWIS)
Last updated: April 2026
Methodology: Contaminant levels are compared against both EPA legal limits (Maximum Contaminant Levels) and EWG health guidelines, which are often stricter and based on the latest scientific research.
