Columbia Gas of Pa. will begin pipeline replacement on several Mt. Lebanon streets starting next week, with work continuing Monday through Friday, 7 a.m. to 5 p.m. with possible lane restrictions on Sunnyhill Drive, Seminole Drive and Forest Glen. The project is expected to last through late summer, weather permitting. Columbia will personally contact any residents whose gas service will be affected. If you drive in the area, please allow extra time.