PFAS Contamination in Delaware
Per- and polyfluoroalkyl substances (PFAS) detected in Delaware drinking water systems. Data from EPA UCMR 5 monitoring covering 62 public water systems.
Systems Tested
62
Detection Rate
38.7%
Exceeding MCL
5
Max Level
18 ppt
PFAS Overview: Delaware
Detection Rate
38.7%
of systems tested
vs National Average
+4.3%
National avg: 34.4%
PFAS Detections
24
systems with any PFAS
Exceed EPA MCL (4 ppt)
5 (8.1%)
of tested systems
State notes: DuPont chemical legacy in region influences contamination
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 Delaware have PFAS in the water?
Yes. Delaware has a 38.7% PFAS detection rate across 62 tested public water systems, according to EPA UCMR 5 data. This means 24 systems detected at least one PFAS compound. The national average detection rate is 34.4%, so Delaware is 4.3 percentage points above average.
How bad is PFAS contamination in Delaware?
Delaware's PFAS contamination is rated moderate severity. The maximum recorded PFAS level is 18 ppt, compared to the EPA MCL of 4 ppt for PFOA and PFOS. 5 systems exceed the EPA MCL, representing 8.1% of tested systems. DuPont chemical legacy in region influences contamination
What can I do to reduce PFAS exposure in Delaware?
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