Stretches of the Susquehanna River in New York and Pennsylvania were receding Friday morning after days of rainfall from what had been Tropical Storm Lee flooded communities around the Northeast, sweeping homes off their foundations and forcing nearly 100,000 people to seek higher ground. At least 11 deaths have been blamed on Lee and its remnants. Officials have also warned that the floodwaters were tainted with sewage and other toxins. "We face a public health emergency because sewage treatment plants are underwater and no longer working," Republican Pennsylvania Governor Tom Corbett said as flooding from Lee's rains hit central and eastern Pennsylvania. "Flood water is toxic and polluted. If you don't have to be in it, keep out," he added. "We're worried about people even getting near the water." President Barack Obama declared states of emergency in Pennsylvania and New York early Friday, clearing the way for federal aid.