A North Grenville woman is facing charges after driving while impaired. 42-year-old Mary-Ellen Montgomery was stopped by police on Saturday, December 6th around 5pm after reports that she was driving erratically on Highway 138 in North Stormont. Police found a small amount of suspected heroin in her vehicle and charged her with possession and careless driving. The next day, on December 7th, Montgomery was again arrested, this time because her vehicle ended up in a ditch and investigation showed she was under the influence of a drug. She was held in custody pending a bail appearance in Cornwall court today.