A huge spill of coal slurry into streams in eastern Kentucky has caused water shortages and school closings and prompted Kentucky Gov. Paul Patton (D) to declare a state of emergency in 10 counties. About 250 million gallons of coal waste with the consistency of wet cement have spilled out of a retention pond at a coal-preparation plant since last Wednesday, and the muck has made its way from streams to the Big Sandy and Ohio rivers, threatening to shut down as many as 25 water treatment plants in Kentucky and West Virginia. About 75 miles of rivers and streams have been turned black by what is being called one of the worst environmental disasters ever to hit the Southeast. The cleanup, expected to cost millions, could take up to six months.