Wilmington, DE water treatment
What's in Wilmington's water, who supplies it, and how to fix what you find, with sources. Check your ZIP for your utility's EPA records.
Your water in Wilmington
WÜDR is based in Wilmington, at 520 Robinson Lane. The City of Wilmington Water Department serves about 108,000 people with surface water from the Brandywine Creek watershed, treated at the Brandywine and Porter filter plants[1][2]. Homes outside city service may be on Artesian Water, Veolia Water Delaware, or a private well, so check your bill.
The City's 2025 water quality report puts average hardness at 136 ppm at the Brandywine plant (range 94–190) and 154 ppm at the Porter plant (range 100–228)[2], roughly 8 to 9 grains per gallon. In EPA's UCMR 5 sampling the system reported PFOA up to 9.9 ppt[3], above Delaware's 4.0 ppt limit that took effect in January 2026[4]. Its latest lead result was 0 ppb at the 90th percentile[1].
Local issues to know
- Hardness: The City of Wilmington's Porter Filter Plant reported 154 mg/L as calcium carbonate, about 9.0 grains per gallon on average in the 2025 report (Brandywine plant: 136 mg/L)[2]. The USGS calls 61–120 mg/L moderately hard and 121–180 mg/L hard[5]. See hard water and our hardness by town table.
- PFAS: Delaware's PFOA and PFOS limits of 4.0 ppt took effect in January 2026[4]. Utilities post results on Delaware Drinking Water Watch[6].
- Older homes: lead can come from service lines and solder even when utility sampling is low[7]. See lead.
Utility records
City of Wilmington Water Department
EPA water system ID DE0000663 · serves about 107,976 people · surface water (rivers, streams, or reservoirs)
- Health violations
- No health-based violations in the last three years; 1 older on record (water treatment rule (filtration / disinfection), Oct 2017, resolved)[1]
- Lead
- 0 ppb at the 90th percentile of its most recent lead sampling (EPA action level: 15 ppb)[7]
- PFAS
- EPA UCMR 5 sampling found PFOA up to 9.9 ppt, PFPeA up to 32.2 ppt, PFHxA up to 21.1 ppt, PFBA up to 14.1 ppt, so PFOA was above the 4.0 ppt federal limit that takes effect in 2029.[3]
Full EPA record for this system · Ask the utility for its annual Consumer Confidence Report (CCR) for hardness and other details[8].
Recommended for Wilmington homes
Comparing options? See tankless vs. tank reverse osmosis and all five WÜDR systems.
How it works
- Analysis: your free ZIP report and quiz, or a free in-home test (always, for wells).
- Recommendation: a system matched to your results.
- Price: shown only after the analysis.
- Install: buy on your own or talk it through first.
Check your water in Wilmington
Look up what your local water utility has reported to the EPA, then take a 60-second quiz about what you see, taste, and smell at home. We'll use both to recommend the right solution.
Get your water report
Enter your ZIP code to see your utility's violations, lead testing, and PFAS results from public EPA records, explained in plain English.
Data comes from U.S. EPA and Census public records. It covers public water systems, not private wells, and it isn't a test of your home's tap. If you're on a well, a free in-home test is the best way to know what's in your water.
Water self-check quiz
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Wilmington water questions
How hard is Wilmington, DE water?
The City's 2025 report lists average hardness of 136 ppm at the Brandywine Filter Plant and 154 ppm at the Porter Filter Plant, about 8 to 9 grains per gallon. That's in the hard range.
Does Wilmington water have PFAS?
EPA UCMR 5 sampling found PFOA up to 9.9 ppt on the City system. Delaware's 4.0 ppt limits for PFOA and PFOS took effect in January 2026; check the City's latest report for compliance updates.
Is WÜDR local to Wilmington?
Yes. We're at 520 Robinson Ln, Unit 5, Wilmington, DE 19805. Call (609) 379-2122 or book a free in-home test.
Book a free water test in Wilmington
Sources
- U.S. EPA: SDWIS Federal Reports (violations, lead and copper results). sdwis.epa.gov/ords/sfdw_pub/r/sfdw/sdwis_fed_reports_public/200
- City of Wilmington, DE: 2025 Water Quality Report. ccrwilmingtonde.com/2025_City_of_Wilmington_Water_Quality_Report.pdf
- U.S. EPA: UCMR occurrence data. www.epa.gov/dwucmr/occurrence-data-unregulated-contaminant-monitoring-rule
- Delaware Public Health: PFAS in Delaware public drinking water. publichealthalerts.delaware.gov/pfas-in-delaware-public-drinking-water/
- USGS Water Science School: Hardness of water. www.usgs.gov/special-topics/water-science-school/science/hardness-water
- Delaware Drinking Water Watch. drinkingwater.dhss.delaware.gov/
- U.S. EPA: Basic information about lead in drinking water. www.epa.gov/ground-water-and-drinking-water/basic-information-about-lead-drinking-water
- U.S. EPA: Consumer Confidence Reports (CCR) information for consumers. www.epa.gov/ccr/ccr-information-consumers
EPA records retrieved Oct 2026 from the EPA SDWIS and UCMR 5 public datasets. Utility records describe a water system, not the tap in your home. Records can lag and may be incomplete.