With their quaint barrel-like contours and weathered cedar-plank sides, rooftop water towers are a constant on the New York City skyline. And though they may look like relics of a past age, millions of residents get their drinking water from the tanks every day.
But inside these rustic-looking vessels, there are often thick layers of muddy sediment. Many have not been cleaned or inspected in years. And regulations governing water tanks are rarely enforced, an examination by The New York Times shows.
Even some that are routinely maintained contain E. coli, a bacterium that is used by public health officials to predict the presence of viruses, bacteria and parasites that can cause disease.
When found in drinking water, E. coli, a microbe carried in the feces of mammals and birds, requires the issuance of a boil-water order, according to federal Environmental Protection Agency regulations.
Samplings taken by The New York Times from water towers at 12 buildings in Manhattan, Queens and Brooklyn found E. coli in five tanks, and coliform in those tanks and three more. Coliform by itself is not harmful, but does indicate that conditions are ripe for the growth of potentially dangerous microorganisms. The positive results all came from the bottoms of the tanks, below the pipe that feeds the buildings’ taps, though public health experts say the contamination is still a concern because the water circulates throughout the inside of the tanks.