Repair and restoration work has started on a covered bridge in Greenfield that was knocked off its abutments by the remnants of Hurricane Irene in August 2011. The work will cost about $1 million. The federal government will pick up about 60 percent of the cost, and the rest will come from the town’s state road aid apportionment. Mayor William Martin said the bridge will be lifted from its abutments and set in the nearby parking area while being restored. At the same time, the stone abutments will be reinforced. Martin told The Recorder that he hopes the bridge will be open to pedestrians and light vehicular traffic by the fall.