PFAS Contamination in District of Columbia
Per- and polyfluoroalkyl substances (PFAS) detected in District of Columbia drinking water systems. Data from EPA UCMR 5 monitoring covering 2 public water systems.
Systems Tested
2
Detection Rate
50%
Exceeding MCL
1
Max Level
6 ppt
PFAS Overview: District of Columbia
Detection Rate
50%
of systems tested
vs National Average
+15.6%
National avg: 34.4%
PFAS Detections
1
systems with any PFAS
Exceed EPA MCL (4 ppt)
1 (50.0%)
of tested systems
State notes: Very few large public water systems; PFAS detected above threshold in at least one
EPA PFAS Standards (2024)
In April 2024, the EPA finalized Maximum Contaminant Levels (MCLs) for six PFAS compounds. Water systems must comply by 2029.
| Compound | MCL |
|---|---|
| PFOA | 4 ppt |
| PFOS | 4 ppt |
| PFNA | 10 ppt |
| PFHxS | 10 ppt |
| HFPO DA_GenX | 10 ppt |
Source: EPA Final PFAS NPDWR, April 2024. Compliance required by 2029.
Health Effects of PFAS Exposure
Cancer Risk
PFOA and PFOS are associated with kidney, testicular, and other cancers
Thyroid Disruption
PFAS can interfere with thyroid hormone function
Immune Effects
Reduced vaccine response and immune system impairment in children
Reproductive Harm
Linked to pregnancy complications and reduced fertility
Liver Damage
Elevated liver enzymes and liver disease risk
Developmental Effects
Harm to fetal development and child growth
Frequently Asked Questions
Does District of Columbia have PFAS in the water?
Yes. District of Columbia has a 50% PFAS detection rate across 2 tested public water systems, according to EPA UCMR 5 data. This means 1 systems detected at least one PFAS compound. The national average detection rate is 34.4%, so District of Columbia is 15.6 percentage points above average.
How bad is PFAS contamination in District of Columbia?
District of Columbia's PFAS contamination is rated high severity. The maximum recorded PFAS level is 6 ppt, compared to the EPA MCL of 4 ppt for PFOA and PFOS. 1 systems exceed the EPA MCL, representing 50.0% of tested systems. Very few large public water systems; PFAS detected above threshold in at least one
What can I do to reduce PFAS exposure in District of Columbia?
The most effective options are reverse osmosis (RO) filtration systems, which remove up to 90-95% of PFAS, and granular activated carbon (GAC) filters certified under NSF/ANSI Standard 58 or 62. Standard pitcher filters provide limited protection. Contact your water utility to request PFAS test results, or check the EPA's UCMR 5 data portal for your system's specific readings.
What is the EPA MCL for PFAS?
The EPA finalized Maximum Contaminant Levels (MCLs) for PFAS in April 2024: 4 parts per trillion (ppt) each for PFOA and PFOS, and 10 ppt each for PFNA, PFHxS, and HFPO-DA (GenX). Water systems have until 2029 to comply. These are the strictest PFAS drinking water standards in the world.
National Comparison
Reduce PFAS Exposure
- +Use a reverse osmosis filter (most effective)
- +Look for NSF/ANSI 58 or 62 certified systems
- +Granular activated carbon (GAC) filters reduce PFAS
- +Standard pitcher filters offer limited protection
- +Request PFAS test results from your utility