Burns Waterway has been tested weekly for hexavalent chromium following April's spill at a U.S. Steel facility.
Tuesday's U.S. Steel spill, caused by a pipe failure, allowed wastewater containing hexavalent chromium to enter a tributary 100 yards from Lake Michigan.
The donated land will be developed into a hiking and playing area.
Two Indiana Harbor Belt Co. locomotives started a series of wildfires at Indiana Dunes in 2012.
Scientists are trying to discover why a sand dune collapsed last year, swallowing a six-year-old boy.
Indiana Dunes State Park and Indiana Dunes National Lakeshore are restoring wild blue lupine, the main food source of the endangered Karner blue butterfly.
The National Parks Service reports the Indiana Dunes National Lakeshore lost $4 million during October's government shutdown.