Wilmington – Delaware – Water Quality Report 2025: PFAS Testing, Infrastructure Concerns & Safety across your city
Wilmington Water provides comprehensive water and wastewater services to over 450,000 residents across the City of Wilmington and northern New Castle County, Delaware. Dating back to the 1800s, this municipal utility has evolved into a state-of-the-art operation encompassing approximately 2,500 miles of water distribution lines, multiple treatment facilities, and advanced pumping stations that deliver an average of 50 million gallons of drinking water daily to Delaware’s largest city and surrounding communities.
Wilmington sources its drinking water primarily from the Brandywine Creek, supplemented by Hoopes Reservoir, Delaware’s largest water storage facility. The water is treated at the historic Brandywine Filter Plant, which underwent a complete modernization in 2013 with cutting-edge membrane filtration technology, and the Porter Water Treatment Plant featuring slow sand filtration technology. Wilmington’s water consistently meets all federal and state quality standards, though the utility faces ongoing challenges with aging infrastructure, emerging contaminants like PFAS, and the need for lead service line replacement. The utility has implemented significant investments in treatment technology, conservation initiatives, and system modernization to ensure sustainable water supply for future generations.
Wilmington Water Quality: Current Status (2024-2025)
Latest Testing Results
- Lead and Copper Monitoring: Wilmington has maintained excellent compliance with EPA’s Lead and Copper Rule since 1991, with the most recent testing showing levels well below federal action thresholds.
- Service Line Inventory: Of the more than 74,000 water service lines in the system, fewer than 2,000 were found to be made of lead, with replacement required by 2037 under new federal regulations.
- Compliance Status: Wilmington’s water consistently meets all federal and state drinking water standards for the latest quarter assessed (April-June 2024), maintaining compliance with EPA and Delaware Division of Public Health regulations.
Water Sources
- Brandywine Creek: Primary source located in the Brandywine Creek watershed spanning portions of three Pennsylvania counties and New Castle County, with water traveling 2-6 days from headwaters to treatment.
- Hoopes Reservoir: Delaware’s largest water storage facility holding up to 2.2 billion gallons, serving as backup supply and constructed with a unique 135-foot concrete gravity dam.
- Watershed Protection: Comprehensive watershed management program including monitoring and pollution control efforts to safeguard the Brandywine Creek watershed from agricultural, industrial, and stormwater impacts.
Advanced Treatment Technology
- Brandywine Filter Plant: Delaware’s first membrane water treatment plant, unveiled in 2013, utilizing tiny hollow fiber membranes instead of traditional sand filtration to remove pathogens and particulates.
- Porter Water Treatment Plant: Historic facility using slow sand filtration technology to purify water from the Brandywine Creek and Hoopes Reservoir, with ongoing modernization efforts.
- PFAS Treatment Project: New granular activated carbon (GAC) filtration system under construction with 21 pairs of carbon vessels, expected completion by Q2 2025 to address emerging PFAS contamination.
Infrastructure Modernization
- System Improvements: Ongoing investments in water main replacements, pumping station upgrades, and electrical system improvements to maintain reliable service and reduce water loss from aging infrastructure.
- Lead Service Line Replacement: Implementation of fair and equitable replacement plan for lead service lines, with comprehensive inventory completed and customer assistance programs available.
- Smart Water Management: Advanced monitoring systems throughout the distribution network, including meter replacement programs and leak detection initiatives that have saved 3 million gallons per day.
Customer Protection Initiatives
Wilmington Water provides extensive customer support through various programs, including the Water Utility Assistance Program offering $350,000 annually to help residents with delinquent bills, and free water quality testing for concerned customers. The utility launched a new dedicated website at WilmingtonDEWater.gov in 2024 to improve customer service and access to water quality information. Educational outreach helps residents understand water quality, conservation practices, and lead reduction measures. Wilmington’s commitment includes transparent communication through annual water quality reports and proactive preparation for emerging contaminant regulations, demonstrating dedication to providing safe, reliable drinking water while addressing future challenges including PFAS treatment and lead service line replacement.
Recommendations for Wilmington Residents
Check Your Service Lines
Complete Wilmington’s service line survey at WilmingtonDEWater.gov to help identify materials in your home’s plumbing. Free lead testing is available by contacting (302) 576-2620 or emailing waterqualitylab@wilmingtonde.gov.
Conserve Water
Take advantage of Wilmington’s conservation programs and follow water-saving practices. The city has invested in green infrastructure projects including wetlands restoration and stormwater management systems to protect water resources.
Consider Home Filtration
While Wilmington’s water meets all standards, homes with older plumbing or concerns about emerging contaminants like PFAS may benefit from NSF-certified GAC filters for drinking and cooking water.
Manage Your Account Online
Visit WilmingtonDEWater.gov to pay bills, set up automatic payments, track water usage, and access educational information about water quality and conservation programs. Monthly billing helps manage costs and identify leaks faster.
Report Issues
Contact Wilmington 311 at (302) 576-2620 for water emergencies, pressure problems, or quality concerns. Report leaks promptly to help conserve water and maintain system integrity throughout the distribution network.
Frequently Asked Questions
Is Wilmington’s tap water safe to drink?
Yes, Wilmington’s tap water meets all federal and state drinking water standards. The city’s water comes from the Brandywine Creek and Hoopes Reservoir, both of which undergo comprehensive treatment using advanced membrane filtration and slow sand filtration technologies.
Wilmington Water conducts extensive testing to ensure water quality compliance. Treatment processes at the Brandywine Filter Plant and Porter Water Treatment Plant incorporate multiple barriers against contaminants, ensuring safe drinking water. The utility’s commitment to water quality is demonstrated through transparent reporting in annual water quality reports and proactive preparation for emerging contaminant regulations like PFAS.
Why are water bills increasing in Wilmington?
Wilmington has implemented structured rate increases to fund critical infrastructure improvements:
1. Infrastructure modernization: Replacing aging water mains, upgrading treatment facilities, and modernizing pumping stations
2. Regulatory compliance: Installing PFAS treatment systems and replacing lead service lines as required by federal regulations
3. Service expansion: Supporting growth in the region while maintaining high water quality standards
The FY 2025 budget included a 5.8% water/sewer rate increase and 4% stormwater rate increase, with funding for the Water Utility Assistance Program increased to $350,000 to help qualifying residents manage costs.
Does Wilmington have lead in its water system?
Wilmington has maintained excellent compliance with EPA’s Lead and Copper Rule since 1991:
• Service line inventory: Of more than 74,000 service lines, fewer than 2,000 were found to be made of lead, with fewer than 1,000 galvanized lines requiring replacement
• Treatment protection: Wilmington’s water treatment process specifically addresses potential lead leaching through corrosion control and pH optimization
• Lead-free at source: Water is lead-free when it leaves treatment plants; any lead exposure would come from service lines or internal building plumbing
• Replacement plan: Under federal regulations, all lead service lines must be replaced by 2037, with fair and equitable replacement planning underway
Homes built before 1988 have higher likelihood of containing lead plumbing components, which is why free testing and customer assistance are available.
What is Wilmington doing about PFAS?
Wilmington is proactively addressing PFAS contamination ahead of EPA regulations:
Treatment system construction:
• New PFAS treatment facility under construction since November 2023, expected completion Q2 2025
• 21 pairs of granular activated carbon vessels to filter PFAS from water supply
• System designed to achieve undetectable PFAS levels in treated water
Current monitoring:
• Voluntary quarterly testing since 2022 to gather data and guide decision-making
• Recent testing shows PFAS levels in low to mid-20 parts per trillion range
• Full compliance anticipated with EPA’s 4 ppt limit for PFOS and PFOA by 2029 deadline
Contaminants of Concern
PFAS Compounds
Source: Per- and polyfluoroalkyl substances from industrial processes, firefighting foams, and consumer products that can enter source waters from upstream industrial activities and atmospheric deposition
Health Effects: Research suggests potential impacts on immune system, thyroid function, cholesterol levels, liver function, and possible links to certain cancers
Current Levels: Recent testing shows levels in low to mid-20 parts per trillion range, with new GAC treatment system under construction to achieve undetectable levels EPA Limits: 4 ppt for PFOS and PFOA, with compliance required by 2029
Lead and Copper
Source: Lead service lines, galvanized pipes previously connected to lead, and internal building plumbing in homes built before 1988 when lead solder was prohibited
Health Effects: Lead exposure can cause developmental delays in children, neurological damage, anemia, and reproductive issues; copper exposure may cause gastrointestinal distress and liver damage
Current Status: Excellent compliance with EPA regulations since 1991; fewer than 2,000 lead service lines identified out of 74,000+ total lines EPA Limits: 15 ppb action level for lead; 1.3 ppm action level for copper
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