 About 1 million gallons of coal ash wastewater leaked from a power plant in Cohasset in north central Minnesota. Dan Crocker says it happened at the Boswell Energy Center. Duluth-based Minnesota Power reported the spill at 11.30 a.m. Tuesday, according to the Minnesota Pollution Control Agency. The utility says the leak occurred from an underground pipeline that transfers the wastewater from an inactive coal combustion residual pond to the plant for process water.