SUPERFUND SITE REMEDY RETURNS RECREATIONAL PARK TO COMMUNITY

摘要

Since 1999, the residents of Harrison Township, Pennsylvania have been enjoying their new Community Park and adjacent greenspace which was once a waste disposal site known principally for its presence on the Superfund National Priorities List (NPL). Between the mid 1800’s and the mid 1900’s approximately 1.2 million cubic yards of wastes from the production of inorganic and organic chemicals and steel, and mining debris, were placed beneath the surface of this site, which is located in Allegheny County in the Pittsburgh metropolitan area. When the site was promulgated onto the NPL, concerns included surface exposure of waste materials, leachate discharges, and stormwater runoff. As one of the predominant potentially responsible parties (PRPs), ATOFINA Chemicals, Inc., partnered with the Township, the Pennsylvania Department of Environmental Protection, and EPA Region III to seek a secure outcome for this real estate. ATOFINA constructed an interim collection and treatment system for the leachate discharges to the Allegheny River. This was followed by a Remedial Investigation to characterize the site and potential risks, a Feasibility Study to evaluate options for remediating the potential risks, and a Remedial Design/Remedial Action to construct the selected remedy. ATOFINA committed to construct, operate, and maintain the remedy so that the properties could be redeveloped as a community park and greenspace. An 18-acre geocomposite, low permeability capping system was constructed atop the graded waste. Leachate and affected shallow groundwater were contained by an improved collection system and a new permanent treatment system. The park facilities were constructed on the upper portion of the site, which include 2 baseball fields, 2 tennis courts, and a picnic area. Landscaping employs shallow rooted shrubs and trees and a hardy grass ground cover. The adjacent greenspace is grassed. Challenges presented during the project and their resolutions are also discussed herein.