REVERE – Electricity provider National Grid will start upgrading transmission lines running through Revere, Saugus and Lynn beginning this month with work expected to be completed in late 2008.Utility crews will replace wires, poles and other supporting structures along the line route running from National Grid’s Golden Hills substation and along the Saugus and Melrose border through Revere’s Franklin Park, crossing the Rumney Marsh reservation in Saugus and running through Bear Creek and the Saugus River into Lynn, ending at the General Edwards Bridge.Most of the work will be done in the utility’s transmission line right of way with minimal traffic impact. The work will occur Monday through Saturday with some Sunday work anticipated so that any work occurring while the transmission line is out of service can be quickly completed.The line can only be taken out of service during times, like weekends, when customer demand is low.Workers will use helicopters and barges to complete repairs along sections of the Saugus River.National Grid delivers electricity to approximately 3.3 million customers in Massachusetts, New Hampshire, New York and Rhode Island, and manages the electricity network on Long Island under an agreement with the Long Island Power Authority.National Grid is the largest power producer in New York state, owning 6,650 megawatts of electricity generation that provides power to over one million customers on Long Island and supplies roughly a quarter of New York City’s electricity needs.The utility is also the largest distributor of natural gas in the northeastern U.S., serving approximately 3.4 million customers in New York, Massachusetts, New Hampshire and Rhode Island.