The Navy Ships Parts Control Center is an 824-acre federal facility in Mechanicsburg, Pennsylvania. Operations dating to the 1940s and early 1950s left the site contaminated with metals, solvents, lubricants, and polychlorinated biphenyls (PCBs). EPA added it to the National Priorities List (NPL) in May 1994. The NPL flags sites that need thorough investigation and long-term cleanup under the federal Superfund program.
Contamination affects both soil and groundwater across multiple areas of the site. Groundwater at Site 3 contains volatile organic compounds (VOCs) like trichloroethene, benzene, vinyl chloride, and carbon tetrachloride, along with pesticides, metals, and PCBs. Soils at Project Sites 8 and 9 contain arsenic, manganese, PCBs, and polycyclic aromatic hydrocarbons (PAHs). In 2019, the Navy also identified 11 areas where per- and polyfluoroalkyl substances (PFAS), specifically PFOA and PFOS from firefighting foam, were used and began sampling private wells within one mile of the base.
The Department of the Navy leads cleanup under a Federal Facilities Agreement signed in November 2004 with EPA and the Pennsylvania Department of Environmental Protection. Remedies have been selected for eight operable units, covering actions such as excavation and off-site disposal of contaminated soil, in-situ chemical oxidation of groundwater, stream stabilization, and land use controls. Most construction work finished between 2010 and 2012. Four operable units received "No Further Action" determinations. However, groundwater contamination remains above allowable levels. A 2016 pilot study for a groundwater treatment method called in-situ biogeochemical transformation was only partially effective, and EPA and the Navy are now discussing a Technical Impracticability waiver, which would acknowledge that full cleanup to standard levels may not be feasible. Three operable units, including areas related to PFAS, do not yet have cleanup decision documents. Remedial investigations for two of those units began in October 2024 and are expected to finish between late 2026 and early 2027.
Land use controls are in place to prevent construction of residences, daycares, schools, and playgrounds in restricted areas and to block access to contaminated groundwater. EPA assessments indicate human exposure is currently under control, meaning no unacceptable exposure pathways exist at this time. Groundwater migration, however, is not yet stabilized, and the site has not reached construction completion or deletion from the NPL. The most recent five-year review was completed in January 2024, and the next is scheduled for 2028.
Community members can follow progress through Restoration Advisory Board meetings, which are open to the public. The Navy maintains the Administrative Record, which can be reviewed at the Navy's Mechanicsburg NSA website or at EPA Region III in Philadelphia. Appointments to review records can be scheduled by calling (215) 814-2396.
