Control of NAPL Migration to Sensitive Environmental Receptors Using Engineering Controls

摘要

This paper will describe various engineering controls used to control coal tar NAPL migration at a former MGP site. The former plant site and adjacent areas consist of a variety of land uses including: residential (apartment complex, condos, and houses); public (including a park and athletic fields); commercial (strip mall with supermarket and retail); and industrial. Sensitive environmental receptors potentially impacted by NAPL include a stream corridor, adjacent wetlands, and a public highway. The engineering controls used to mitigate NAPL migration include: sealing of leaking stormwater pipes and a large culvert beneath a major highway to prevent infiltration of NAPL/ groundwater, installation of subsurface barrier walls and pumping systems to control NAPL migration/groundwater flow, and installation of soil and asphalt caps to prevent direct contact. The engineering controls have been used in conjunction with institutional controls as remedial measures to protect human health and the environment and when permanent remedies are not feasible. This paper will describe the decision-making process for selecting engineering controls, and the technical, regulatory and community relations aspects of implementing the installation of the engineering controls.