Federal regulators have agreed to investigate whether the North Carolina Department of Environment Quality violated the rights of minority residents and poor people living near farms where it approved plans to capture gas from hog waste. The U.S. Environmental Protection Agency wrote this week saying it had accepted a complaint filed in October by the Southern Environmental Law Center. The complaint alleges the state’s water quality permit modifications contained “inadequate” protections for nearby communities in Duplin and Sampson counties. EPA says moving forward with the investigation doesn’t reflect any decision on the merits of the allegations.