Latest Testing Results (2024 Consumer Confidence Report)

• PFAS Detection: PFOA detected at 7.05 ppt, exceeding the new EPA MCL of 4 ppt; multiple PFAS compounds found including PFBA (7.30 ppt), PFHxA (9.49 ppt), and PFPeA (11.7 ppt). Testing was completed under EPA’s UCMR 5 monitoring programme for 29 PFAS compounds.
• Disinfection Byproducts: Bromodichloromethane detected at 165x above EWG’s health guideline (9.87 ppb vs 0.06 ppb guideline); bromochloroacetic acid at 182x above guideline (3.63 ppb vs 0.02 ppb). Total trihalomethanes at 38.1 ppb; haloacetic acids at 43.0 ppb — both legally compliant but above health guidelines.
• Compliance Status: For the latest quarter assessed by the EPA (April–June 2024), Wilmington’s water was in compliance with all federal health-based drinking water standards. Fifteen contaminants exceed EWG health guidelines. Legal limits have not been updated in nearly 20 years.

Water Sources

• Brandywine Creek: Primary source, rated the highest susceptibility to contamination from pathogens, metals, nutrients, and petroleum hydrocarbons. The watershed spans portions of three Pennsylvania counties with over 72 identified pollution sources — principally wastewater and stormwater discharges.
• Regional PFAS Contamination: DNREC’s 2024 statewide surface water study confirmed widespread PFAS across Delaware’s 33 watersheds. Six priority watersheds — including Shellpot Creek in the Wilmington area — have been selected for further investigation and mitigation. Red Clay Creek shows PFAS levels as high as 135 ppt.
• Watershed Challenges: The Brandywine Creek watershed faces ongoing contamination from industrial discharges, stormwater runoff, agricultural activity, and underground storage tanks across its multi-state drainage area. In April 2025 the Delaware River Basin Commission published Enhanced Monitoring for Toxics and Emerging Contaminants in Delaware Estuary Tributaries, confirming elevated PCBs, dioxins, and PFAS in Christina River surface water near Wilmington.

Treatment Technology & Funding

• Current Treatment: Water treatment at the Brandywine Filter Plant and Porter Filter Plant uses conventional processes including chlorination and coagulation. Chlorination effectively removes microbial contaminants but creates trihalomethane and haloacetic acid disinfection byproducts.
• PFAS Treatment Investment: Wilmington has secured nearly $80 million in total Bipartisan Infrastructure Law funding for infrastructure and treatment upgrades. A further $2 million PFAS-specific grant was announced in January 2026 via the EPA’s Emerging Contaminants in Small or Disadvantaged Communities programme. The earlier $7 million State Revolving Fund award included $4.1 million in principal forgiveness.
• Compliance Timeline: Water systems must meet EPA’s 4 ppt MCL for PFOA and PFOS by April 2031 (compliance deadline extended from the originally proposed 2029 date). Monitoring under UCMR 5 for 29 PFAS compounds is complete; results inform the treatment upgrade programme.

Infrastructure Concerns

• Lead Service Line Replacement: The Service Line Inventory Map was released in October 2024, developed in partnership with the University of Delaware Water Resources Center following review of over 70,000 work orders dating to 1916. The programme has checked 100 city blocks, identified lines for 1,700 properties, and replaced nearly 1,000 with approximately 2.6 miles of copper pipe. In 2025, Wilmington received $10 million (100% forgiveness) via the State Revolving Fund for lead service line replacement.
• Triennial Lead Testing (2026): As Wilmington has complied with the Lead and Copper Rule for a sustained period, it now tests every three years rather than annually. A systemwide triennial sampling of 50 locations is planned for summer 2026. Residents can sign up to participate at WilmingtonDEWater.gov.
• Ongoing System Modernisation: Over the last ten years, Wilmington has invested more than $200 million from various funding sources, including reinforcement of the Hoopes Reservoir, construction of a renewable energy facility at the Regional Wastewater Treatment Plant, and protection of the South Wilmington wetlands.

Customer Protection Initiatives

Wilmington Water published its 2024 Consumer Confidence Report in spring 2025, confirming the water meets or exceeds all EPA and state standards. The utility serves a predominantly disadvantaged community — over 70% of the city’s 25 census tracts are classified as disadvantaged and nearly 47% of residents meet the EPA’s low-income definition — which has qualified Wilmington for significant grant funding. A Pitcher/Filter Programme is available for residents concerned about lead exposure. Residents can access the Service Line Inventory Map, pay bills, and request free lead testing at WilmingtonDEWater.gov, or call the Water Quality Lab at (302) 571-4158. For broader U.S. water quality information and filter recommendations tailored to PFAS and DBPs, see our dedicated guides. Stay updated on any water safety events via our water alert news section.