The 550-acre Sand Creek Industrial site is located in Denver and Commerce City, Colorado, in a heavily industrial area. Since the 1940s, several different types of businesses have operated at the site. They include an oil refinery, a pesticide manufacturing facility, an herbicide chemical plant and a landfill. Site operations, waste management practices, spills and explosions at the site contaminated soil, air, groundwater and surface water with hazardous chemicals. Following cleanup, EPA took the site off the Superfund program�s National Priorities List (NPL) in 1996. Operation and maintenance activities are ongoing.