What's in Delaware Tap Water? Test Results and Solutions

Delaware has some of the highest PFAS "forever chemical" contamination levels on the East Coast. The Department of Natural Resources and Environmental Control has confirmed PFAS in groundwater across New Castle, Kent, and Sussex counties — with some private wells testing above federal health advisories. Combined with hard water and aging pipes in cities like Wilmington, Delaware tap water needs filtration to meet modern safety standards.

Delaware is a small state, but it's densely populated and sits at the intersection of Mid-Atlantic industry, agriculture, and military activity. That combination has left a measurable contamination footprint on the state's drinking water.

PFAS Is the Biggest Concern

The U.S. Environmental Protection Agency has identified multiple PFAS hotspots across Delaware:

• Dover Air Force Base: Decades of firefighting foam use contaminated local groundwater. Private wells near the base have tested above federal limits.
• New Castle County: Industrial sites from Wilmington's chemical industry heritage have leached PFAS into the water table.
• Blades, Delaware: A 2018 discovery of elevated PFAS forced the town to temporarily shut down drinking water wells.
• Sussex County: Agricultural PFAS from biosolids and firefighting foam at regional airports.

PFAS ("forever chemicals") don't break down in the environment or in the human body. Exposure is cumulative — every glass of PFAS-contaminated water adds to what's already in you. They've been linked to:

• Kidney and testicular cancer
• Thyroid disease
• Decreased vaccine response in children
• Ulcerative colitis
• Cholesterol abnormalities

The EPA set enforceable limits for six PFAS compounds in 2024, but water utilities have until 2029 to comply. Until then, household filtration is the only guaranteed protection.

Delaware Water Hardness

Delaware water averages 150 PPM of hardness (8.8 grains per gallon) — classified as "hard water." Specific areas:

• Wilmington and New Castle County: 140-160 PPM
• Kent County (Dover): 140-170 PPM
• Sussex County (beaches): 150-200 PPM in well water areas

Hard water's effects on your home:

• Scale buildup reducing water heater efficiency by 25-50%
• Clogged showerheads and faucets
• Spotted dishes and glassware
• Dry skin and dull hair
• Shortened appliance life (washers, dishwashers, ice makers)

Sussex County beach-area homes with private wells often have extremely hard water — 200+ PPM with iron and sulfur.

Lead Pipes in Older Cities

Wilmington was founded in 1638 and has one of the oldest water infrastructures in the region. Lead service lines are widespread in neighborhoods built before 1986. The City of Wilmington has an active lead service line replacement program, but replacement is slow and homeowners are often responsible for the lead pipe portion on their property.

If your Delaware home was built before 1986, there's a reasonable chance lead plumbing is somewhere in your water path — either the municipal service line or the pipes inside your home.

Chlorine and Disinfection Byproducts

Delaware water utilities use chlorine or chloramine to disinfect water. When these react with organic matter in reservoirs and rivers, they form trihalomethanes (TTHMs) and haloacetic acids (HAA5s) — both classified as probable human carcinogens.

The Delaware River is a surface water source with high organic content, which means TTHM levels in Wilmington and surrounding New Castle County trend higher than the national average.

Private Well Concerns (Sussex and Kent Counties)

Approximately 30% of Delaware residents rely on private wells — especially in rural Sussex and Kent counties. Private wells aren't regulated by the EPA or the state — testing and treatment are entirely the homeowner's responsibility.

Common private well contaminants in Delaware:

• Nitrates (agricultural runoff)
• Bacteria (E. coli, coliform)
• Iron and manganese (natural geology)
• PFAS (near known contamination sites)
• Arsenic (naturally occurring in some regions)

If you have a private well in Delaware, annual testing is strongly recommended.

How to Protect Your Home

The right solution depends on what's in your specific water and whether you're on city water or well water:

For city water (PFAS + chlorine + hardness + lead): A whole-house filtration and softening system handles all four issues. Entry-point treatment protects every tap and shower.

For well water: A more comprehensive approach — typically a multi-stage system with sediment filtration, iron/sulfur removal, softening, and PFAS-specific carbon filtration.

For drinking water only: An under-sink reverse osmosis system provides bottled-water quality at your kitchen tap.

Most Delaware homes benefit from whole-house treatment because shower water (which your skin absorbs) matters as much as drinking water for PFAS and chlorine exposure.

Get Your Water Tested

A free home water test is the only way to know what's in your specific home's water. Aquaworld Alkalino serves New Castle, Kent, and Sussex counties with on-site testing. A certified technician tests your water at the tap and shows you exactly what's there — at no cost, no obligation. See our Delaware service area.

Frequently Asked Questions

Is Delaware tap water safe to drink?

Delaware tap water meets federal EPA standards, but has documented PFAS contamination across all three counties, aging lead service lines in Wilmington, and hard water affecting appliances. Long-term health risks are cumulative.

Does Delaware have PFAS in drinking water?

Yes. The Delaware DNREC has confirmed PFAS contamination in groundwater in multiple locations, including near Dover Air Force Base, Blades, and industrial sites in New Castle County. Private wells in affected areas have tested above federal health advisories.

Is Wilmington water safe?

Wilmington's treated water meets EPA standards, but the city has known lead service lines from its pre-1986 infrastructure. Homes built before 1986 may have lead exposure from service lines or internal plumbing.

How do I test my Delaware well water?

Private wells aren't regulated — homeowners must test voluntarily. Annual testing is recommended, especially for nitrates, bacteria, PFAS, and iron. Aquaworld Alkalino provides free on-site water testing in Delaware.

What's the best water filter for PFAS in Delaware?

Reverse osmosis and activated carbon block filters certified for PFAS removal (NSF/ANSI 53 and 58) are the most effective. Standard pitcher filters don't remove PFAS. Whole-house treatment combined with drinking water RO is the gold standard.