The Avco Lycoming site is a 28-acre former aircraft engine manufacturing and repair facility in Williamsport, Pennsylvania. It has been on the EPA's National Priorities List since February 21, 1990. Decades of industrial operations left the shallow and deep groundwater aquifers contaminated, though surface water in nearby Lycoming Creek was not affected.
The contaminants in groundwater include the solvents trichloroethene, cis- and trans-1,2-dichloroethene, and vinyl chloride, plus the metals barium, cadmium, chromium(VI), and manganese. A Human Health Risk Assessment found that ingesting contaminated groundwater posed an unacceptable health risk. The site is divided into two cleanup areas: one targeting metals using air stripping and onsite treatment, and one targeting volatile organic compounds (VOCs) using vapor extraction, air sparging, and monitoring.
Cleanup started in 1985 after Pennsylvania regulators ordered an investigation. EPA studies from 1989 to 1991 mapped the contamination and set the cleanup strategy. A pump-and-treat system was built and running by 2001, with extra extraction wells added in 2002 to address high-contamination zones. Vapor intrusion testing found no issues in 2010, but a concern was identified in 2011 and mitigation systems were installed in affected homes. All construction was finished in September 2002. Metals remediation work ran from 1997 to 2003, and VOC treatment work covered the same period with a second phase from 2000 to 2003.
As of the most recent Five-Year Review in September 2022, the remedy is functioning as intended and is protective of human health and the environment. Human exposure and groundwater migration are both under control. The site is not yet ready for unrestricted use, and a Record of Decision amendment for the VOC treatment area is estimated to be finalized between April and June 2028, with a combined remedial investigation and feasibility study expected to wrap up between October and December 2027. Institutional controls restrict the property to industrial use and prohibit new groundwater wells within the contaminated plume. One business currently operates on-site, employing 530 people and generating about $222 million in annual sales.
Community members who want to learn more or stay involved can contact the EPA staff assigned to the site. Key documents, including Five-Year Reviews and Federal Register Notices, are available at the James V. Brown Library in Williamsport or at the EPA Region 3 office in Philadelphia. Appointments to review records can be made by calling the Philadelphia office at (215) 814-2396.
