The law firm Reger Rizzo Kavulich & Darnall is opening a Harrisburg office. The office will be staffed by attorneys David P. Zambito and Louise A. Knight, previously of Saul Ewing. They were named Reger Rizzo partners. Zambito and Knight represent private and governmental clients in fields including energy, water, wastewater, telecommunications and transportation. Reger Rizzo’s main office is in Philadelphia, according to the firm’s Web site. The firm has six other locations, including the Harrisburg office at 20 N. Market Square.