Wilmington West Yard has operated as a railcar and equipment staging yard since 1884. Amtrak acquired Wilmington West Yard in April 1976 from the Pennsylvania Central Transportation Company (Penn Central) pursuant to the Regional Rail Reorganization Act of 1973. The site is operated by Amtrak with some of the rail leased to Norfolk Southern Corporation.

Since the construction of the yard, operations have consisted primarily of the staging of railcars, material staging and the staging of other equipment associated with railroad activities. The site consists of several sets of storage tracks, an access road, a High-Speed Training Center and an electrical substation. The electrical substation is located in the facility and is operated by Amtrak. The High-Speed Training Center was constructed on the northern portion of the facility from 1999 to 2000. Historically, equipment maintenance has not been conducted at the facility other than minor maintenance and repairs. The facility was formerly electrified with overhead catenary wires. The catenary wires were later removed, but the structures remain.

Impacts to the soil were originally investigated in 1992 by the Delaware Department of Natural Resources and Environmental Control (DNREC) underground storage tank (UST) branch. The investigation oversaw the abandonment of three oil USTs within the electrical substation enclosure. PCBs were identified in the vicinity of the abandoned USTs. The USTs were located within the substation enclosure that had previously been abandoned in place and were reported to contain mineral oil. However, PCBs were detected in soil samples associated with the closure of these USTs. Previous use of the substation may have included transformers or other equipment that historically used PCBs. In 1998, a geotechnical investigation was conducted in relation to the construction of the High-Speed Training Center. PCBs were detected at various concentrations in boring samples. In 2001, DNREC conducted a Brownfield Preliminary Assessment II (BPA II). The BPA II focused on on-site surface soils, saturated and unsaturated subsurface soil, groundwater and sediment. The results of this investigation indicated that organic and inorganic/heavy metal substances were present in site soils above the EPA and DNREC screening benchmarks.

Heavy metal contamination was detected above the DNREC screening levels in soils and sediment throughout the facility during sampling events in 2017 and 2018 and is likely due to coal ash residues and fill, as well as offsite industrial, manufacturing and waste disposal activities.

As the site owner, Amtrak has continued the Remedial Investigation (RI) activities. Amtrak entered the Site into the Voluntary Cleanup Plan (VCP) Program with DNREC in November 2013. The remedial investigation workplan (RIWP) was prepared in May 2017. The RI was performed to identify the extent of the impact and was completed in 2019. During the RI, PCB impacts in the soil were discovered at varying concentration levels. Following a comment and response period, DNREC approved the RI report in August 2022. The next step is to develop a Focused Feasibility Study (FFS) to identify restoration option(s) for DNREC review and approval. The Proposed Plan for Remedial Action at the site will receive public comment prior to the development of the Final Plan of Remedial Action.

The remedial goal is to remove PCB-impacted soil to meet the Delaware Hazardous Substance Cleanup Act (HSCA) standard.