Salem Keyspan - MGP Site Remediation - Phase IV Remedy
Client: Private Client
Project Description: At a former MGP site in Salem, TFCI installed a 5 acre Engineered Barrier and Stormwater collection and treatment system. The site is an operating LNG storage and distribution facility. The Engineered Barrier consisted of a Geosynthetic Clay Barrier (GCL) with a Geocomposite drainage layer on top and a gravel cover. Most of the site was also paved. Prior to installing the Engineered Barrier TFCI installed an extensive stormwater collection and treatment system which discharges to ocean outfalls. Because of the contamination in the ground the system was designed to be water tight to prevent infiltration of impacted groundwater. Corrugated HDPE pipe with watertight Nitrile gasketed joints was installed and pressure tested to verify the integrity of the joints. All precast concrete manholes and catch basins were vacuum tested. The two biggest challenges to the work were the presence of many historic and abandoned underground structures and pipes and the need to keep the facility in operation.