Remediation of NAPL-contaminated aquifers: is the cure worth the cost?

Millions of dollars are spent in the United States each year to design, construct, and operate systems intended to remediate groundwater impacted by dense non-aqueous phase liquids (DNAPLs), such as trichloroethlene (TCE) and tetrachloroethene (PCE), or light non-aqueous phase liquids (LNAPLs), such as gasoline, diesel, and jet fuel. However, several recent studies suggest that many of these groundwater remediation systems may operate for decades without restoring groundwater to background conditions. This paper examines the potential economic impacts of continuing the current regulatory approach to remediation of NAPL-contaminated aquifers versus considering regionally contaminated aquifers as large storage basins instead of pristine resources. Treating water at the point of extraction when needed, provides an equivalent benefit and may be more practical and cost effective than attempting to restore aquifers to background conditions at the point of contamination.