PFAS in Washington D.C. drinking water
3 drinking-water utilities in Washington D.C. reported PFAS detections at or above the EPA minimum reporting level under UCMR 5 (the federal monitoring round that ran 2023–2025). None of those detections exceeded the new federal Maximum Contaminant Level (4 ppt for PFOA or PFOS), but every reading sits above the level utilities are required to report under EPA’s UCMR 5 monitoring rule.
By the numbers
- 3 Washington D.C. water utilities with at least one PFAS compound detected
- 665,214 people served by those utilities
- 4 federal and Department of Defense sites with reported PFAS in groundwater
The interactive map below plots every reporting Washington D.C. utility, colour-coded by whether their worst reading exceeds the federal MCL, sits below it but at or above the reporting threshold, or falls below the reporting threshold. Use the search box to find a specific utility, ZIP code or address.
Top Washington D.C. water utilities by PFAS impact
The 15 Washington D.C. public water systems with the most significant PFAS detections under UCMR 5, ranked by how far each system’s worst MCL-exceeding compound runs over the federal limit:
| # | Utility | Population served | Headline ng/L | Compound | vs MCL |
|---|---|---|---|---|---|
| 1 | D.C. Water and Sewer Authority | 632,323 | 4.7 | PFPeA | Detected only |
| 2 | Joint Base Anacostia – Bolling | 17,201 | 4.3 | PFHxA | Detected only |
| 3 | Naval Station Washington – Wny | 15,690 | 3.8 | PFHxA | Detected only |
Use the interactive map above to find every utility (not just the top 15) and to search by ZIP code or address.
PFAS compounds detected in Washington D.C.
UCMR 5 required utilities to test for 29 different PFAS compounds. The table below shows how many Washington D.C. utilities had at least one above-reporting-level result for each compound, sorted by frequency:
| Compound | Washington D.C. utilities | Share of detecting utilities | EPA MCL |
|---|---|---|---|
| PFHxA | 3 | 100% | None |
| PFPeA | 3 | 100% | None |
Where Washington D.C.’s PFAS contamination is coming from
EPA’s PFAS Analytic Tools also catalogue the suspected industrial, federal and accidental sources of PFAS in each state. Washington D.C. has 4 federal facilities (mostly U.S. military installations and federal airports) reporting PFAS in groundwater, 1 EPA Superfund site flagged for PFAS, and 1 recorded PFAS-related spill (1 of which reached surface water).
Superfund sites flagged for PFAS in Washington D.C.
EPA’s Superfund program has identified the following Washington D.C. site with confirmed PFAS detections:
- Washington Navy Yard, Washington, District of Columbia County. NPL status: Final. EPA site report
Recent PFAS-related spills in Washington D.C.
- 2024: 500 gallons of aqueous film-forming foam (AFFF) released in Anacostia (Washington D.C. County) by US Airforce Jbab. Reached water.
What “exceeds the MCL” means here
In April 2024 the EPA finalised the first-ever federal Maximum Contaminant Levels (MCLs) for six PFAS compounds in drinking water. The two most consequential are PFOA and PFOS, both set at 4.0 nanograms per litre (ng/L) — equivalent to 4 parts per trillion. Every red marker on the map above represents a Washington D.C. water system whose most-recent UCMR 5 result for PFOA or PFOS sat above 4 ng/L.
EPA also issued individual MCLs of 10 ng/L for PFHxS, PFNA and HFPO-DA (GenX) and a Hazard-Index MCL covering mixtures. In May 2025 the agency confirmed the PFOA and PFOS limits would stay in place (with the compliance deadline extended to 2031), and announced its intent to rescind the four other limits. We continue to flag exceedances of the published April 2024 MCL for those compounds and label them as “under EPA reconsideration” so the rule status is honest and current.
Yellow markers mean PFAS were detected at or above EPA’s reporting threshold (the minimum reporting level) but no individual compound exceeded an MCL. Detection at any level is not necessarily a regulatory violation, but it is a signal that PFAS treatment may be needed before the 2031 compliance deadline.
Methodology and data sources
- Drinking-water detections: EPA PFAS Analytic Tools, UCMR 5 layer. Filtered to Washington D.C. samples at or above the minimum reporting level. We aggregate the raw 2023–2025 sample records to one entry per public water system, taking the most-recent reading per compound.
- Superfund sites: EPA PFAS Analytic Tools, Superfund-with-PFAS layer. Includes National Priorities List sites and Superfund Alternative Approach sites where PFAS has been detected.
- Federal and DoD sites: EPA PFAS Analytic Tools, federal-sites layer. PFOA and PFOS values are maximum readings from groundwater monitoring wells at each installation, not finished drinking water.
- Spills: EPA PFAS Analytic Tools, spills layer. Covers reported releases involving PFAS-containing materials.
UCMR 5 only required community water systems serving 3,300 or more people, plus a representative sample of smaller systems, to test for PFAS. Private wells, very small public systems, and bottled water are not in this dataset. Absence of a dot on the map does not mean absence of PFAS.
What you can do
- Check whether your utility appears in the table above or on the map. If it does, your utility is required to come into compliance with the federal PFOA/PFOS MCL by 2031 — usually via granular activated carbon, ion-exchange resin or reverse osmosis treatment.
- If you are on a private well in or near a flagged area, consider independent PFAS testing through a state-certified laboratory.
- Look up your most recent Consumer Confidence Report (CCR), which utilities are required to publish annually. PFAS results from UCMR 5 must now appear there.
- If you want point-of-use protection, only filters certified to NSF/ANSI 53 or NSF/ANSI 58 for PFOA and PFOS reduction will reliably remove PFAS.
