But once the floodwaters recede, the damage will go beyond rebuilding homes, bridges, and roads destroyed by extreme rains. Residents in the flood-soaked areas will have to worry about sewage, pesticides, and other contaminants that were left behind by the flood or that were swept into East Coast waterways. One New York apartment building has already been evacuated because oil carried by the floodwaters contaminated several apartments. The U.S. Geological Survey sent crews to follow the storm and test for bacteria and chemicals in rivers, according to the New York Times:
“What typically happens is that you get a significant amount of rainfall that leads to a significant amount of runoff,” said Charles Crawford, sampling coordinator for the agency.
That runoff, he said, carries pesticides from farmland, gardens and lawns like those used for termites around the foundation of homes. [...] Excessive amounts of nutrients like nitrogen and phosphorus, Mr. Crawford said, could cause algae blooms that can threaten aquatic life and fisheries. And sewage in the high flows from the hurricane can lead to higher concentrations of E. Coli in areas that use surface water for drinking, he said.
Contaminated water is frequently a problem following flooding from heavy rains or storm surge from a massive hurricane. After Hurricane Katrina, tests found extremely high levels of sewage bacteria in water samples. When thunderstorms deluged Nashville in May 2010, health officials warned residents to treat all floodwater as if it had sewage in it because of reports about overflowing sewage systems. Floodwaters from the Mississippi River in May swept pesticides and fertilizer down the river and into the Gulf of Mexico, and this highly polluted water swamped 3 million acres of farmland along the way.
Global warming continues to make hurricanes more intense and dangerous and fuels more “500-year” floods along the Mississippi River. “Once in a lifetime” storms are no longer a rarity, and handling the dangerous chemicals dispursed by these floodwaters and heavy rains will continue to potentially endanger people’s health and harm aquatic life in waterways as weather patterns continue to grow more extreme.