The Dover, New Hampshire zip code area of 03820 currently operates under a critical environmental hazard designation due to regional proximity to multiple active Superfund locations. While zero sites exist within a five-mile radius, five active facilities operate within ten miles. The primary regulatory concern is the Cardinal Landfill, situated 7.2 miles from the area center. Other proximate regional facilities include the former Collins and Aikman Plant, the Dover Municipal Landfill, the Somersworth Sanitary Landfill, and the Tibbetts Road site. All five regional sites maintain an active National Priorities List status, indicating that the Environmental Protection Agency is currently overseeing ongoing investigation, containment, or remediation efforts at these distinct geographic locations.

The Cardinal Landfill and surrounding facilities manage uncharacterized and unspecified hazardous substances. Exposure to such legacy industrial waste typically occurs through groundwater migration plumes or soil vapor intrusion into residential basements. Long-term contact with these uncharacterized chemical mixtures compromises local drinking water quality, potentially causing systemic organ toxicity, severe neurological impairments, and elevated carcinogenic risks depending on the precise chemical profiles involved. Due to ongoing regional groundwater vulnerability, residents relying on private wells should immediately commission comprehensive drinking water testing through a state-certified laboratory to screen for volatile organic compounds and dangerous heavy metals. Residents must also install high-efficiency reverse osmosis filtration systems at point-of-use water taps to systematically mitigate ingestion risks. Furthermore, property owners should proactively consult municipal utility records to verify if local drinking water supplies draw from underlying aquifers positioned near these active federal remediation zones.