Alstead, New Hampshire, within the 03602 zip code, carries a high environmental hazard designation due to its proximity to active industrial cleanup zones. While there are zero sites within five miles, the broader ten-mile radius contains four active facilities currently under strict federal monitoring. The most prominent is the BFI Sanitary Landfill facility in Rockingham, located 9.1 miles away, alongside the Steamtown USA site, Simmonds Precision Inc, and the Whitney Blake Company of Vermont.

The primary threat identified at the BFI Sanitary Landfill involves unspecified hazardous substances. In historical landfill environments, these uncharacterized wastes typically manifest as volatile organic compounds and heavy metals that migrate through groundwater or soil vapor. Prolonged exposure to these toxic substances can lead to chronic respiratory irritation, neurological impairment, and long-term organ toxicity depending on specific concentration levels. The Environmental Protection Agency currently lists this location as an active National Priorities List site. This federal regulatory status indicates ongoing environmental investigation and active remediation efforts, meaning agencies are actively managing contamination pathways to prevent further migration into municipal watersheds and private aquifers.

Given the potential for groundwater transmission of persistent landfill contaminants, residents relying on private well water should conduct comprehensive annual testing for heavy metals and volatile organic compounds. Property owners must install certified reverse osmosis filtration systems if baseline water diagnostics indicate elevated contaminant levels. Furthermore, residents should routinely review public health updates from the state environmental department regarding local groundwater and soil quality monitoring adjacent to these four active federal remediation zones.