The landscape of eastern North Carolina is dotted with giant pools of bright pink sludge. These are waste lagoons, where industrial farms across the state dispose of billions of gallons of untreated pig urine and feces every year.

Image A 2014 image of an animal waste lagoon on a hog farm in North Carolina. Credit... Zach Frailey/Kinston Free Press, via Associated Press

The waste can carry E. coli, salmonella, cryptosporidium and other bacteria that can lead to serious illness or death if they spread to humans. After Hurricane Matthew deluged North Carolina this month, at least 14 of the lagoons flooded.

Environmental advocates and state officials have been flying over regions to identify overflowing lagoons where floodwaters have become mixed with the waste, a public health hazard that could last for weeks as bacteria flow into rivers and streams, potentially sickening those who come into contact with those waters.