Around the time of the last factories' closing, environmental efforts to clean up the river progressed. For example, GE participated in cleanup efforts to remove PCBs from the site of its old factory in Hudson Falls. The cleanup is part of an EPA Superfund site, and consists of dredging a 40-mile stretch of the river the Troy Dam to Fort Edward in order to remove the probable carcinogen from the ecosystem. Other conservation efforts also occurred, such as when Christopher Swain became the first person to swim all 315 miles of the Hudson River in support of cleaning it up.