In industrial nations the revitalized environmental movement has spawned a fresh offensive against pollution. Detectives are hired to track down those who contaminate waterways.

Swaminathan Asokan dreams of water. It gushes out of a giant tap and fills bucket after bucket. But then he wakes up — to a nightmare. For at Asokan’s house in Madras, India’s fourth largest city, there is no water. The tap has long been dry. So he must get…