In 1972 Asarco's downtown Omaha plant in Nebraska was found to be releasing high amounts of lead into the air and ground surrounding the plant. In 1995 Asarco submitted a demolition and site cleanup plan to the Nebraska Department of Environmental Quality for their impact on the local residential area. Fined $3.6 million in 1996 for discharging lead and other pollutants into the Missouri River, Asarco closed its Omaha plant in July 1997. After extensive site cleanup, the land was turned over to the City of Omaha as a park. All of East Omaha, comprising more than 8,000 acres (32 km²), was declared a Superfund site. As of 2003, 290 acres (1.2 km²) had been cleaned.