Americans have been warned for years not to drink the water when traveling to Mexico for fear of contracting “Montezuma’s Revenge,” or what’s known as “traveler’s diarrhea.”
According to the CDC, an estimated 10 million people, or roughly 20% to 50% of international travelers develop traveler’s diarrhea annually, and the most common cause in countries surveyed has been a form of E. coli.
But according to a hard-hitting investigate piece by the New York Times, the risk of getting E. Coli from drinking water may be just as great for New York City residents.
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.
While coliform by itself is not harmful, its presence indicates conditions are ripe for the growth of potentially dangerous microorganisms.
Dr. Stephen C. Edberg, a public-health microbiologist at Yale University who invented the standard test for bacterial contamination in drinking water, was so horrified by the results he alerted the New York City Department of Health and Mental Hygiene.
“Fecal contamination means that the towers are subject to animal intrusion, almost certainly birds and potentially animals such as squirrels,”Dr. Edberg wrote in an email to the department, adding, “Clearly, these units are not sealed to the outside”
The city’s 311 help line gets dozens of calls each year from residents saying they have become ill from drinking water, but health officials say no cases have ever been traced back to a water tank. Moreover, health officials insist the tanks are safe, and that the laws governing them are adequate.
But as Dr. Edberg points out, that does not mean people are not getting sick.
“It’s very hard, with a population as large and dense as New York, to even ascertain even reasonably large illness outbreaks,”he said. “You’d literally have to have entire apartment buildings getting sick at the same time”
How The Water Tanks Work
To better grasp the gravity of this situation, it’s important to understand how the tanks operate and who monitors them.
New York City’s water system originates at 19 protected lakes and reservoirs in upstate New York.
Water tanks came into widespread use in the late 1800s, and were used because the city’s water mains were unable to supply water to increasingly taller buildings.
The mains provide only enough pressure to deliver water to the sixth floor of most buildings.
Taller buildings use electric pumps to carry water to a spout at the top of the water tanks. An exit pipe about midway down distributes drinking water to the building, while another pipe near the bottom is used for sprinkler systems and firefighting.
City health and buildings officials estimate there are from 12,000 to 17,000, water tanks based on the inventory of buildings that stand seven stories or taller.
But any supervision for these tanks is virtually nonexistent because building owners are not required to submit proof to the city that cleanings and inspections have been conducted.
The Times took samples from 14 drinking water tanks in 12 buildings and reported that samples from eight of the tanks came back with positive results for total coliform.
Five of those also came back positive for E. coli. A positive result for either sample means that the water is not fit for human consumption, according to state and federal standards.
In every instance, the tanks were cleaned after the sampling and retested by cleaning companies, which then reported negative results.
The Times notes each sample was taken near the bottom of the tank where sediment builds up and bacteria and viruses thrive, but below the spigot that feeds the buildings’ faucets.
Still, Dr. Edberg said, “The problem is that if any part of the tank gets contaminated, all of it is contaminated”
Despite this, the city’s health department said the methodology used and the conclusions drawn by The Times were flawed, adding that The Times had used non-sterilized equipment and had not followed suggested testing protocols.
But The Times claims that with the exception of three of the positive samples, in which they took the sample during the cleaning, they followed the protocols exactly as recommended.
Inspection Records Available to Tenants
In 2009, New York City Council passed a bill mandating that building owners make water tank inspection records available to tenants, and to post proof of the inspections in prominent places.
It also required that tank water be tested for contamination once a year. The new law required the health department to conduct three surveys, checking the inspection records of 100 randomly chosen buildings each year from 2010 through 2012.
The Times claims the results were not encouraging.
No more than 42 percent of the buildings surveyed each year could provide proof of a bacteriological test. In other words, 60 percent of building owners do not ensure that their tanks adhere to regulations, according to the city’s own survey.
Of those buildings that could provide proof, all were found to be free of contamination, though the samplings were typically done after the tanks were cleaned, which is allowed.
But even among these buildings, The Times advised that most failed to post their inspection notices, and most could not provide proof that they had performed an inspection in each of the previous five years, as city law also requires.