Title: Geology of Southwest Philadelphia

Abstract: Southeast Pennsylvania and adjacent Southern New Jersey have a complex geology that has been studied starting in the 1840s. Extensive development of the Philadelphia area has been conducted for over 400 years starting in the colonial city area and expanding outwards over time. The area of Southwest Philadelphia (South and West of the Schuylkill River) had limited development until the late 19th Century. The world’s largest ship building yard (Hog Island Shipyard) was constructed starting in 1916 in this area and ceased operations in the mid 1920s. In 1930, this area was designated as the site for the proposed Philadelphia Municipal Airport which became the Philadelphia International Airport (PHL) in the 1950s. It is currently the 16th largest airport in the US and the 51st largest airport in the world. Proper development of the airport, the supporting businesses surrounding it, the regional transportation network, and adjacent residential housing requires detailed knowledge of the underlying geological and hydrogeological conditions. A plan to construct a 4th PHL runway over an adjacent hazardous waste landfill was conceived in the late 1980s and required extensive geological, geotechnical, and hydrogeological studies to properly permit and complete. These data continue to be used to support current PHL, industrial, and residential development and operations occurring in the area, including issues related to area flooding and sea-level rise.  The results of these studies will be summarized during the presentation.