From the Huffington Post:
More than 27 billion gallons of untreated sewage and polluted wastewater spill into New York Harbor every year, often after as little as one-tenth of an inch of rain overloads the city's antiquated plumbing system that combines waste from homes and businesses with normal stormwater. What's more, the public is often left unaware of these sewer overflows, and sight or smell is not always enough to decipher water quality.
"This is a sleeper issue that the public assumed was solved 20 years ago," Judith Enck, regional administrator for the U.S. Environmental Protection Agency (EPA) Region 2 in New York City, told The Huffington Post. "Larger volumes of sewage, a crumbing infrastructure and heavier rains have created the perfect storm."