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State Report

Water & Air Quality in Delaware

Regional composite data for PFAS, lead, and PM2.5 in Delaware. Values are derived from EPA UCMR 5, EWG Tap Water Database, and AirNow annual averages. Check your specific ZIP code below for localized results.

PFAS

5 ppt
125% of EPA 4 ppt limit
Elevated

Lead

5.1 ppb
34% of EPA 15 ppb action level
Elevated

PM2.5

8.5 µg/m³
94% of EPA 9 µg/m³ standard
OK

Delaware Context

Persistent PFAS detected in southern New Castle County; aging infrastructure drives lead risk.

Check Your Specific ZIP Code in Delaware

State averages mask wide local variation. Your ZIP code may be significantly cleaner or more contaminated than the state composite — especially near industrial sites, military bases, or older housing stock.

Audit Delaware ZIP 19131 →

Or go to the home page and enter any Delaware ZIP code.

What These Numbers Mean for Delaware Residents

PFAS in Delaware Drinking Water

Delaware's regional PFAS composite is 5 parts per trillion (ppt), which exceeds the EPA's 2024 enforceable limit of 4 ppt for PFOA and PFOS. Water utilities in Delaware have until 2029 to comply. In the interim, a point-of-use reverse osmosis filter (NSF 58 certified) removes 95%+ of PFAS at the tap.

Lead in Delaware Tap Water

Lead contamination in Delaware averages 5.1 ppb at the 90th percentile. This is at or above concerning levels. Homes built before 1986 face the highest risk from lead service lines and solder. An NSF 53-certified under-sink filter or reverse osmosis system removes lead at the tap.

PM2.5 Air Quality in Delaware

Delaware's annual average PM2.5 is 8.5 µg/m³. This meets the EPA annual standard (9 µg/m³) but exceeds the stricter WHO guideline of 5 µg/m³. A HEPA air purifier in sleeping areas is recommended, particularly for children and people with respiratory conditions.

Filtration Recommendations for Delaware

  • PFAS concern: AquaTru Countertop RO (NSF 58) removes >95% of PFAS — the most effective countertop option. Shop AquaTru →
  • Lead concern: Any NSF 53-certified carbon block filter removes lead at the tap. An RO system covers both PFAS and lead. Shop Berkey →

Delaware Water & Air Resources

Want to go deeper? Read our evidence-based articles on PFAS health effects, water filter comparisons, and PM2.5 air quality. Or audit your specific ZIP code for localized results.