Fifty years ago, Congress voted to override President Richard Nixon's veto of the Clean Water Act. It has proved to be one of the most transformative environmental laws ever enacted. At the time of the law's passage, hundreds of millions of gallons of raw sewage was dumped by New York City into the Hudson River every day. This filth was compounded by industrial contaminants emptied into the river along much of its length. The catch basin for all of this was New York Harbor, which resembled an open sewer. At its worst, 10 feet of raw human waste blanketed portions of the harbor bottom. Health advisories against eating fish from the Hudson remain, but its ecology has largely recovered, thanks to the law, which imposed strict regulations on what could be discharged into the water by sewage treatment plants, factories and other sources of pollution. Today people swim in organized events in New York Harbor, which would have been unthinkable in 1972 when the law was passed. Across the country, billions of dollars were also spent to construct and improve sewage treatment plants, leading to recoveries of other urban waterways. Cleaner water has made the harbor far more hospitable, and other steps have helped to rebuild life there, like fishing restrictions and the removal of some dams on tributaries in the Hudson River watershed. The bald eagle has made a strong comeback, taking advantage of the harbor's resurgent fish life. In December 2020 a humpback whale was seen in the Hudson just one mile from Times Square.