In our cover story, Cowan examines the health threats posed by the prevalence of long-lasting compounds (known as PFAS) in drinking water sources. Also: Tracy Smith talks with tennis legend Chris Evert; Robert Costa interviews retiring Vermont Senator Patrick Leahy; Jim Axelrod profiles one of rock's most enduring couples, Pat Benatar and Neil Giraldo; David Pogue looks at the rise in unionization efforts at Amazon and other corporations; Faith Salie visits an exhibition featuring the work of women artists, many of whom produced their work anonymously; and Seth Doane finds out how Birkenstock is going toe-to-toe with counterfeiters.