As a boy in a small Wisconsin town on Lake Michigan, I nearly lived on the river. (The section of stream in my neighborhood was actually an estuary, and I grew up thinking it was normal for a river current to reverse direction rhythmically.)Anyway, my neighborhood chums and I spent our summers fishing for bullheads and carp, angling for crayfish with liver tied to pieces of string, floating on makeshift rafts, and building huts out of sticks and marsh grass.But never swimming. Our parents wouldn’t allow it. The water was too polluted, they said. This was back in the 1960s,
