A CASE STUDY OF REMEDIAL ACTION AND CLOSURE AT A FORMER MANUFACTURED GAS PLANT SITE

摘要

This paper addresses the remediation of a former Manufactured Gas Plant (MGP) Site in western Massachusetts. The Site was located approximately 500 feet from two municipal wellheads and surrounded by residential dwellings. Contamination consisted of Polynuclear Aromatic Hydrocarbons (PAHs) and Volatile Organic Hydrocarbons (VOCs) within soils above a clay layer. Contaminated soil depths ranged from 2 to 20 feet below ground surface (bgs). The remediation included the excavation of approximately 26,000 square feet (SF) of a wetland and 8,500 SF of buffer zone soils. The soils were treated by thermal desorption and off site disposal and the wetland and buffer zone were restored. Groundwater remediation was achieved by a combination of source area removal and natural attenuation as part of a Monitored Natural Attenuation (MNA) plan. Site closure maximized the risk reduction and resulted in a condition of No Significant Risk under current conditions for a residential exposure scenario.