PFAS in Drinking Water in Delaware
What residents of Delaware need to know about PFAS ("forever chemicals") in drinking water — including contamination sources, which utilities have documented violations, and how to filter PFAS from tap water.
Source: EPA SDWIS, Delaware Division of Public Health, CDC · Last reviewed: 2025-01-01
Quick Answer
Is PFAS in drinking water a real concern in Delaware?
Yes. Delaware has PFAS concerns tied to DuPont/Chemours manufacturing legacy and industrial facilities along the Christina River and in New Castle County. While Delaware's contamination profile differs from the AFFF-military hotspots common in other states, its industrial chemical manufacturing history — including fluoropolymer production — means PFAS has been present in the environment for decades.
Where does PFAS come from in Delaware?
Industrial fluoropolymer and specialty chemical manufacturing in northern Delaware, particularly in the Wilmington/New Castle County area, represents the primary PFAS source. DuPont's long manufacturing presence in Delaware has left PFAS-related contamination in surface water and some groundwater. Additionally, fire training areas at state and local facilities contribute to PFAS loading.
What should Delaware residents know?
Delaware residents in northern New Castle County near legacy DuPont/Chemours industrial sites should review their utility's PFAS testing data. The state's proximity to New Jersey's Chemours Washington Works plant (across the Delaware River) also means shared watershed concerns. Delaware DPH has expanded PFAS monitoring under UCMR5.
Key Facts
| EPA MCL (PFOA/PFOS) | 4 ppt — effective April 2024 |
| MCLG | Zero |
| Primary contamination sources | Legacy DuPont/Chemours industrial manufacturing in northern Delaware; fire training areas |
| Watershed concern | Christina River and Brandywine Creek watersheds in New Castle County |
| State regulator | Delaware Division of Public Health |
| Health effects | Cancer (kidney, testicular), thyroid disruption, immune suppression, developmental effects |
| Effective treatment | Reverse osmosis (NSF/ANSI 58) or certified activated carbon for PFAS |
Why PFAS Matters in Delaware
Delaware sits at the center of the DuPont/Chemours fluorochemical manufacturing corridor that spans the Delaware River. While the most infamous contamination site (Washington Works) is in West Virginia, DuPont's extensive Delaware operations have left a PFAS legacy in the state. Industrial facilities in northern Delaware have contributed PFAS to the Christina River watershed, and some groundwater monitoring has detected PFAS in New Castle County. Delaware is a small state where a single industrial site can affect a significant portion of the water supply.
Delaware PFAS Regulation
Delaware DPH participates in EPA UCMR5 monitoring and has flagged the Wilmington/New Castle County industrial corridor as a PFAS priority area. The state has coordinated with New Jersey and Pennsylvania on Delaware River watershed PFAS monitoring given shared source water. Delaware does not have a state MCL more protective than the federal standard.
Largest Delaware Water Utilities
No PFAS violations on record in EPA SDWIS for Delaware utilities in our database. Browse the largest utilities to review their full water quality record.
What Are PFAS (“Forever Chemicals”)?
PFAS are a family of over 12,000 synthetic chemicals used in non-stick cookware, stain-resistant fabrics, food packaging, and AFFF firefighting foam. Their carbon-fluorine bonds do not break down in the environment or the body — hence the name “forever chemicals.” AFFF used at military bases is the single largest source of PFAS in U.S. drinking water.
Full PFAS overview — national data, health effects, all 50 statesWho Should Pay Closest Attention
Residents in Wilmington, Newark, New Castle, and other northern Delaware communities drawing water from the Brandywine Creek or Christina River watersheds face the most relevant risk. Groundwater users in New Castle County near legacy industrial sites should prioritize testing.
Residents near military bases with AFFF use history
Private well owners near military or industrial sites
Pregnant residents and families with young children
Residents in communities with documented PFAS detections
Anyone who has consumed water above 4 ppt for an extended period
Residents near airports, fire training areas, or industrial manufacturers
How to Check Your Situation in Delaware
- 1
Identify your water utility using the ZIP lookup below or by browsing the Delaware utility directory on this site.
- 2
Review your utility's Consumer Confidence Report (CCR) — it must report PFAS monitoring results under UCMR5 and the new MCL.
- 3
Check the EPA's ECHO database for your utility's monitoring history. Look for PFAS, PFOA, PFOS, and related compound results.
- 4
Contact your utility directly and ask for their most recent PFAS test results and whether they are implementing treatment under the 2024 MCL.
- 5
If you use a private well near a military base, airport, or industrial facility, order a PFAS panel test from a state-certified laboratory. Tests typically cost $150–$400.
- 6
If PFAS is detected above 4 ppt in your source water, install a certified NSF/ANSI 58 reverse osmosis system or an NSF/ANSI 53-certified activated carbon filter rated for PFAS removal.
How to Remove PFAS from Tap Water
Reverse Osmosis (Best)
90–99% removal — NSF/ANSI 58 certified systems only
Certified Activated Carbon
Effective with NSF/ANSI 53 or 58 certification — verify before buying
Boiling concentrates PFAS. Standard pitcher filters and water softeners do not remove PFAS. Always verify NSF certification before purchasing.
Take Action Now
Look up your Delaware utility's PFAS monitoring history on the PFAS Watchlist below.
If your utility has detected PFAS above 4 ppt, install an NSF/ANSI 58-certified reverse osmosis system at your drinking tap.
Private well owners near military or industrial sites should order a PFAS panel test ($150–$400 at a state-certified lab).
Request your utility's most recent Consumer Confidence Report — PFAS results must be disclosed under the new 2024 MCL.
Frequently Asked Questions
Related Pages
PFAS — National Overview
All U.S. utilities with PFAS records
Delaware PFAS Watchlist
Live utility PFAS monitoring data
Delaware State Overview
All utilities and water quality data
Reverse Osmosis Guide
Removes 90–99% of PFAS
Activated Carbon Filter Guide
NSF/ANSI 53/58 certified options for PFAS
Arsenic in Drinking Water
Another priority contaminant
All Contaminants
Complete reference library
Data Sources & Provenance
All data on this page is sourced from official U.S. government or public datasets.
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Delaware Division of Public Health ↗