Summary: Former E.P.A. official E. G. Vallianatos talks about his book, Poison Spring: The Secret History of Pollution and The EPA. And we have a conversation with pioneer environmentalist James âGusâ Speth. He co-founded the Natural Resources Defense Council and founded the World Resources Institute. His new memoir, Angels By The River, looks back on his life in public policy -- and also toward the future of the environmental movement.
