David Zwick was a student at Harvard Law School in the early 1970s when he joined a group of promising attorneys working with consumer activist Ralph Nader. He wound up heading a groundbreaking study of the nation's water pollution and launching the first grass-roots clean water movement.
Zwick's research and organizing are credited with spurring passage of the Clean Water Act of 1972 and the Safe Drinking Water Act of 1974. He also was the founder and longtime president of Clean Water Action, an environmental advocacy group with chapters around the nation.
Zwick, 75, died Feb. 5.
"He was the most consequential advocate for clean water and for mobilizing grass-roots efforts combating local water pollution in 45 years," said Nader.
Nader described Zwick as charismatic, hardworking and "one of the unsung heroes of our time."
Zwick was born May 1, 1942, in Rochester, N.Y. He earned a bachelor's degree from the U.S. Coast Guard Academy in Connecticut in 1963, and then served four years as a Coast Guard officer, including 18 months in Vietnam. He went on to earn a law degree and a master's degree in public policy from Harvard University.
In 1971, Zwick co-authored a book based on his research with Nader, "Water Wasteland." The next year, he co-authored the bestselling "Who Runs Congress?"
Zwick's activism coincided with the dawn of the environmental movement. The first Earth Day was in 1970, and the unregulated pollution in the nation's air, land and waterways was gaining the national spotlight.