ARCHBALD, Pa. — Tim Bachak would look out to his backyard most evenings to see wildlife emerging from the forest of birch, maple and oak trees hugging his property.

He regularly spotted black bears, deer and coyotes. Owls would hoot and turkeys would scurry. Bachak, a 43-year-old public school teacher, saw the activity as a sign this former coal town had recharged from its polluting past.