The 9-acre Halby Chemical Co. site is located in an industrial area of the Port of Wilmington in New Castle, Delaware. From 1948 to 1980, a chemical manufacturing plant operated on the southernmost 3 acres of the site. Site operators discharged wastewater from the plant into an unlined lagoon. Wastewater containing chemicals then flowed through an adjacent tidal marsh, through the Lobdell Canal, and into the Christina River. These activities contaminated sediment, soil, surface water and groundwater. Following cleanup, operation and maintenance activities are ongoing.