Sep 01 2010
Pennsylvania coal plants face big changes under planned EPA pollution-control rules
Sign on Bridge near Ppg Plant Protests Air Pollution 02/1973 Image by The U.S. National Archives Original Caption: Sign on Bridge near Ppg Plant Protests Air Pollution 02/1973 U.S. National Archives’ Local Identifier: 412-DA-3885 Photographer: Vachon, John, 1914-1975 Subjects: Ponce (Ponce, More....
