The Lindane Dump sits on a 14-acre park area and a 47.5-acre lower project zone in Harrison Township, Allegheny County, Pennsylvania. Companies dumped mining waste, chemical manufacturing waste, and other industrial debris there from 1850 until 1986. The site was added to the National Priorities List in 1983, making it eligible for federal Superfund cleanup funding and oversight.
Five contaminants have been identified in groundwater at the site. They are benzene, chlorobenzene, delta-hexachlorocyclohexane, gamma-hexachlorocyclohexane (also known as lindane, the pesticide the site is named for), and p,p'-DDT. EPA determined these chemicals pose an unacceptable risk to human health or the environment and targeted them for cleanup.
The cleanup plan, finalized in a 1992 Record of Decision, called for placing a multilayer cap over roughly 18 acres to block contact with contaminated soil and reduce rainwater from soaking through the waste. A leachate collection and treatment system was also built near Karns Road. Treated water is discharged to the Allegheny River under pollution permit requirements. Cap construction ran from spring 1998 to spring 1999. Harrison Township then restored the land as Alsco Community Park, adding tennis courts, baseball fields, picnic areas, pedestrian paths, and parking, along with 150 newly planted trees. Institutional controls, recorded in January 2000 with the Allegheny County Recorder of Deeds, restrict residential development and activities that could damage the cap.
The site is currently in long-term operation and maintenance. The potentially responsible party runs the cap and treatment system and conducts groundwater monitoring under EPA oversight. EPA's 2023 five-year review found the remedy remains protective of human health and the environment. Human exposure pathways are under control, contaminated groundwater is stabilized and not discharging unacceptably to surface water, and physical construction is complete across the entire site. The site is also designated as sitewide ready for anticipated use, meaning all cleanup goals for current and future land uses have been met and required restrictions are in place. The next five-year review is scheduled between August and October 2028.
Community members who want more information can review site documents at two locations: the Harrison Township Municipal Building in Natrona Heights, Pennsylvania, and the EPA Region 3 Public Reading Room in Philadelphia, Pennsylvania. An appointment is needed to view records at the EPA office. Residents can also contact EPA's Community Involvement Coordinator or Remedial Project Manager.
