June 28 Saturday Science Stumper!



Bad is flushing untreated sewage into our estuaries and watersheds, carrying loads of disease-causing bacteria into fragile ecosystems and into areas where human health could be endangered. What could be worse, and what solution is illustrated above?




UV light water quality test.  Photo by Bronx River Alliance Education Director Damian Griffin.


Each week members of the NYC Water Trail Association, like HarborLAB, sample water for laboratories to test for fecal bacteria indicating sewer overflows. One test involves incubating bacteria cultures and then detecting the presence of enterococcus, a genus found in human intestines, by the contaminated vials’ glow when exposed to ultraviolet light. Above you see the results from a lab operated by Bronx River Alliance. HarborLAB initiated sampling in western Queens and samples the water at Gantry Plaza State Park and Willow Lake in Flushing Meadows-Corona Park.

Enterococcus testing is the preferred method for determining swimming beach safety in the U.S., succeeding the old standard of fecal coliform testing in 2004. If a beach shows a five week mean of 35 colony-forming units or  more per 100 milliliters of water, it’s closed. The Virginia Department of Environmental Quality published a great introductory explanation of this process.

HarborLAB minimizes risks by not putting children in sit-on-tops in contaminated waters and urges other groups to do the same, especially in known trouble spots like Hallets Cove in Astoria. Canoes are a drier ride, and rowboats are also a great option. Adults are informed of risks.