TRC Companies Inc. said Thursday that it was responsible for providing air- and water-permitting services for Panda Hummel Station, one of the largest coal-to-natural-gas power-conversion projects in the U.S. Panda Hummel Station, in Shamokin Dam in Snyder County, Pa., will be a natural-gas combined cycle generating facility that replaces a retired Sunbury coal-fired steam electric generating plant that was permanently shut down in 2014. Based in the Wannalancit Mills, TRC provides engineering consulting and construction-management services.