When New York City gets a normal heavy rain, our ancient combine sewer system almost always overflows, sending raw sewage and other contaminants into our waterways. Now that Tropical Storm Irene just blew through, dumping some 13 inches of rain in many areas, we should all be a little worried about how much pollution she left in our water on her way. Since Sunday, crews from the United States Geological Survey have been testing waters all along the East Coast, including large sections of the Hudson River in NYC and upstate, where the bacteria count is always high thanks to CSO.
Federal officials are looking for damage caused by sewage, pesticides, and contaminants that were washed into the water from the shore. The fast, high flowing waters can also stir up sediment and deposit it in new places, leading to clogged oyster beds or the need for new dredging in canals.
Higher rains naturally lead to higher runoff, and Charles Crawford, sampling coordinator for the USGS, said that the runoff “carries pesticides from farmland, gardens and lawns like those used for termites around the foundation of homes.” Crews are also on the lookout for higher levels of bacteria and nutrients like nitrogen and phosphorus that come from sewer discharges, which could cause large algae blooms, threatening fisheries and aquatic life. But more alarming is that high water flows can lead to higher concentrations of E-coli in areas that use surface water for drinking.
John Lipscomb, who does regular water sampling on New York’s rivers for Riverkeeper, said he doesn’t expect pollution levels to be higher in the Hudson River, because the increased rain would dilute the increased overflow. His main concern after Irene has been the massive amounts of debris that ended up in the water. In addition to trees and branches, docks were swept away, marinas were ripped apart, and waterfront furniture like picnic tables were found bobbing in the river.
Spilt oil is also likely to make its way into the water, as Irene caused hundreds of oil spills in New York state. Most of the 253 spills were under 100 gallons, but one tank in Westchester County dumped nearly 2,000 gallons of oil into the environment. Most of the oil, spilled because of high flood waters, meaning that all of it will be carried off into our rivers and oceans.
For updates on New York’s water quality, regularly check the USGS website, where the agency will be posting information about the findings of their water quality tests.
Lead image © David Shankbone via Creative Commons