Born in North Carolina in 1908,  Joseph Mitchell became famous as a reporter for The New Yorker whose writing focused on the lesser-known characters and corners of New York City, in particular its waterfront. Mitchell was a much-admired writer and founder of the South Street Seaport Museum, but was much more proud of placing third in a clam-eating contest by eating 84 clams.

In The Bottom of the Harbor, Mitchell describes in vivid detail the "oily dirty germy" sludge that once covered the bottom of New York Harbor, which occasionally released gas-filled "sludge bubbles" into the air.

While the sludge problem has come a long way since 1951, there is still work to be done. The sludge below the Hudson's waters is now contaminated with PCBs, toxic waste dumped by General Electric from two manufacturing plants on the River.  Clearwater has been fighting for over 30 years alongside other organizations and individuals to address the PCB problem.  In May 2009 dredging of the Hudson finally began.