The GBB Project Team was selected to prepare an update to the Chester County Solid Waste Management Plan (SWMP). In addition, GBB conducted a two-season solid waste characterization study to provide information to, and help guide, the development of the SWMP. GBB performed a week-long waste sort, as part of an ongoing two-season waste characterization study. The two-season waste characterization study was designed to collect waste composition data representative of disposal trends in the warm season and the cold season. Both the warm and cold season sort took place at two sites: the Lanchester Landfill and the SECCRA Landfill. The GBB Project Team developed the waste characterization protocol, determining the amount of material that is typically disposed at each site and the minimum amount of sorted material from each site required to develop a representative dataset. The team oversaw the manual sorting from inbound disposal vehicles and the characterization of self-hauled, commercially generated and construction waste disposed at each site by visual survey. At the conclusion of the two-season study, the data collected was presented to the County, and used to assist the development of its SWMP.