Low-Risk Site Closure Guidance Manual to Accelerate Closure of Low-Risk Sites(PPT)

摘要

Complete cleanup of contaminated groundwater sites is often difficult and consequently, clean closure in the immediate future is unattainable at many sites. This problem is particularly acute at sites with releases of chlorinated solvents, but hydrocarbon and other releases can also result in persistent groundwater concentrations in excess of closure criteria. While contaminant concentrations at such sites may decrease significantly due to remediation and/or natural attenuation, persistent low-levels of groundwater contamination above closure criteria can preclude objectives such as reaching background concentrations or drinking water standards. Therefore, in many cases the sites cannot be closed.