Overview

The Delaware Division of Public Health (DPH) is providing this information in accordance with 16 Del. C. § 3001R–§ 3003R, the Forever Chemicals Mandatory Reporting Act, effective January 15, 2026.

This page provides Delaware residents with information about per- and polyfluoroalkyl substances (PFAS) in public drinking water, how PFAS levels are monitored, and where to find PFAS testing results for public water systems across the state.

What are PFAS?

PFAS are a group of human-made chemicals that have been used in a wide range of industrial and consumer products, including firefighting foam, nonstick cookware, food packaging, and stain-resistant materials. Because these chemicals break down very slowly, they are sometimes referred to as “forever chemicals.”

Certain PFAS may pose health risks when people are exposed to levels above established safety standards over time.

PFAS Monitoring in Delaware Drinking Water

The Office of Drinking Water (ODW) monitors PFAS in public drinking water systems across Delaware in accordance with state and federal requirements.

PFAS monitoring results for public water systems are available through ODW’s Drinking Water Watch system.

View PFAS results by public water system:

Drinking Water Watch: https://drinkingwater.dhss.delaware.gov/

If PFAS monitoring data for a specific public drinking water system are not yet available, ODW will post the results online as soon as they become available. All systems should have a PFAS result by 2027.

PFAS Maximum Contaminant Levels (MCLs)

Delaware has established Maximum Contaminant Levels (MCLs) for certain PFAS chemicals in drinking water. MCLs represent the highest level of a contaminant that is legally allowed in public drinking water and used to protect long-term health.

The table showing the established PFAS MCLs — including PFOA, PFOS, PFHxS, PFNA, HFPO-DA (GenX), and a Hazard Index for mixtures — is included in the PFAS Information Brochure linked below. View this chart to better understand how measured PFAS levels are compared to the state and federal standards.

Download the PFAS Information Brochure at: https://coronavirus.delaware.gov/wp-content/uploads/sites/177/2026/01/PFAS_Brochure.pdf

What Happens if PFAS Levels Exceed an MCL?

If PFAS monitoring shows that a public drinking water system exceeds an established MCL:

  • DPH will notify the affected water utility.
  • The water utility is required to notify its customers by mail.

The mailed notice will include:

  • Information explaining PFAS
  • A chart showing PFAS MCLs
  • The exact PFAS levels detected that exceed the MCLs

PFAS Information for Residents

DPH has developed a PFAS informational brochure for residents that explains:

  • What PFAS are
  • How people may be exposed
  • PFAS drinking water standards
  • What it means if PFAS are detected above an MCL

Download the PFAS Information Brochure: https://coronavirus.delaware.gov/wp-content/uploads/sites/177/2026/01/PFAS_Brochure.pdf

How to Use Drinking Water Watch

A short instructional video explaining how to search for PFAS results in Drinking Water Watch will be available on this page soon.

[Instructional video – coming soon]

Additional Information

For more information about PFAS and drinking water in Delaware, visit: