Is Wilmington, DE Tap Water Safe to Drink?
Wilmington tap water is legally compliant, but one contaminant exceeds health guidelines. Specifically: PFAS above EPA limits (PFOA: 7.05 ppt — limit is 4 ppt each). A point-of-use filter is recommended for drinking and cooking water.
Hardness Scale: Where Wilmington Falls
0Slightly
60Moderate
120Hard
180Very Hard
250Extreme
400+
How Wilmington Compares
Wilmington's water is 84% softer than the national average of 138 PPM - ranking in the bottom 89% for hardness nationwide. Most homes here do not need a softener. Within Delaware, it ranks #5 of 5 cities (29% below the state average of 31 PPM). Among mid-size cities (100k-200k), Wilmington ranks #169 of 189 for hardness.
What Wilmington's Water Means for Your Home
Hardness: 22 PPM - Low Concern
Wilmington's water is slightly hard at 22 PPM. Most households won't notice any issues at this level. Scale buildup is minimal, and a water softener would be overkill. Wilmington is softer than 89% of US cities. If you're thinking about water treatment, contaminant filtration is where to focus your money, not softening.
Contaminants & Safety
Forever chemicals (PFAS) are worth watching here. Wilmington has PFOA at 7.05 ppt, exceeding the EPA's 2024 limit of 4 ppt per compound. PFAS are synthetic compounds that accumulate in your body over time. A certified carbon filter or reverse osmosis system with NSF P473 certification is the most effective protection. See the regulatory timeline.
What's in the Treatment Process
Wilmington's surface water supply requires heavy chlorination to stay safe — but that creates a tradeoff. The treatment process generates disinfection byproducts: TTHMs at 38.1 ppb (48% of the legal limit, but 254x the EWG guideline) and HAA5 at 24.4 ppb (41% of the legal limit, but 244x the EWG guideline). These are within legal limits, but the EWG sets much tighter thresholds based on cancer-risk research. A whole-house activated carbon filter reduces both chlorine and byproducts.
Chromium-6 was detected at 0.316 ppb, which is 16x the EWG health guideline. There's no separate federal limit for chromium-6, only total chromium. A reverse osmosis system is the most effective removal method. All measurements are within federal legal limits. The EWG guidelines represent a more conservative, health-based standard.
| Contaminant | Detected | Health Guideline | Legal Limit | Status |
|---|---|---|---|---|
| Hardness (as CaCO₃) | 22 PPM | < 60 PPM | No federal limit | ✓ OK |
| Total Dissolved Solids | 62 PPM | < 300 PPM | 500 PPM | ✓ OK |
| PFAS (total) | 44.52 ppt | — | No total limit | Detected |
| ↳ PFOA | 7.05 ppt | 0 ppt | 4 ppt (2024) | ⚠ Exceeds |
| ↳ PFOS | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| Lead | 2.2 ppb | 0 ppb (no safe level) | 15 ppb (10 ppb in 2027) | ✓ Low |
| Chlorine / Chloramine | 1.2 mg/L | Taste threshold ~1.0 | 4.0 mg/L | ✓ Normal |
| Nitrate | 2.39 mg/L | 5 mg/L | 10 mg/L | ✓ OK |
Recommended Filter for Wilmington
PFAS exceed EPA limits (PFOA: 7.05 ppt — limit: 4 ppt each). A certified filter reduces these contaminants effectively.
Quick Fix for Chlorine: Shower Filter
At 1.2 mg/L chlorine, many Wilmington residents notice dry skin, brittle hair, and that "pool smell" in the shower. A shower filter installs in 5 minutes, no tools needed.
How to Test Your Water in Wilmington
With PFAS at 44.52 ppt in Wilmington's supply, confirming your home's specific levels is especially important. PFAS vary by neighborhood and can concentrate differently depending on your position in the distribution system.
Free option: Request City of Wilmington's annual Consumer Confidence Report for official city-level data.
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About Wilmington's Water Supply
Water Utility: City of Wilmington
Water Source: Brandywine Creek (Surface Water)
Population Served: 107,976
Hardness: 22 PPM (1.3 grains per gallon)
Wilmington's drinking water comes from surface sources — Brandywine Creek. Surface water requires more extensive treatment than groundwater, including coagulation, filtration, and disinfection. This heavier chlorination is why disinfection byproducts tend to be higher in surface-supplied systems. On the upside, surface sources often deliver softer water than deep aquifers. The system serves 108,000 residents.
Water quality can vary by neighborhood and season. For your exact numbers, request City of Wilmington's Consumer Confidence Report (CCR) or test your own tap.
ZIP Codes Covered by This Report
This water quality data applies to all areas served by City of Wilmington in Wilmington, DE, including ZIP codes:
08001, 08014, 08023, 08039, 08067, 08069, 08070, 08079, 08085, 08098, 19014, 19060, 19061, 19703, 19710, 19726, 19732, 19735, 19801, 19802, 19803, 19804, 19805, 19806, 19807, 19808, 19809, 19810, 19850, 19880, 19884, 19885, 19886, 19890, 19891, 19892, 19893, 19894, 19895, 19896, 19897, 19898, 19899
If your ZIP code is listed above, this report covers your water supply. Water quality may vary slightly by neighborhood.
Compare Wilmington to Other Delaware Cities
Frequently Asked Questions About Wilmington Water
Is Wilmington tap water safe to drink?
Where does Wilmington's water come from?
Do I need a water softener in Wilmington?
How do I remove PFAS from Wilmington tap water?
What water filter is best for Wilmington?
Is Wilmington water safe for babies and infants?
What are disinfection byproducts in Wilmington's water?
Is chromium-6 in Wilmington's water?
Data sources: Lead and copper data from EPA Safe Drinking Water Act LCR reporting. Contaminant data from utility-reported testing results. PFAS data from EPA UCMR5 (2023–2025). Hardness from USGS and municipal reports. Data reflects system-level testing results and may not match your specific tap due to neighborhood plumbing, season, or recent utility changes. For your utility's latest results, request their Consumer Confidence Report (CCR). Our methodology. Last updated: 2026-02-24.
What Wilmington Homeowners Actually Buy
Prioritized for contaminant reduction for homes with 22 PPM water and PFAS above EPA limits.
Affiliate disclosure: we may earn a commission. Selection based on Wilmington's water data.