NAHANT-After working without a contract since Aug. 31, the Nahant Teachers’ Union has reached an agreement with the school district.Interim Superintendent Joseph Lisi said the new three-year contract was signed on Thursday morning and is retroactive to the beginning of the current academic year.The new contract gives teachers a 4 percent raise for the current fiscal year, a 3 percent raise in fiscal year 2009 and another 3 percent increase in fiscal year 2010.?What is significant in this contract is the elimination of longevity for future hires,” he said. “Longevity gets to be a fairly sizeable amount.”Lisi said longevity payments cost the district $19,000 last year alone.Attempts to reach union representatives were unsuccessful Thursday, but according to Lisi, other provisions in the contract are very similar to the earlier contract.?I think it was a positive experience for both sides,” he said. ” The negotiations were very cordial and the teachers association was very cooperative.”Former Superintendent / Principal Denise Littlefield, who resigned Oct. 31, was unable to negotiate a contract before her abrupt departure. Lisi took over on Sept. 4.As of now, all unions in town are working with contracts. Town Administrator Mark Cullinan signed agreements with the police, fire and Department of Public Works unions in June. Cullinan said the contracts, which went into effect July 1, gave workers in all three departments a 4 percent raise the first year, 3 percent the second year and 3 percent in the final year of the contract. Cullinan said union contracts on the town side are equitable across departments in terms of vacation time, personal time, longevity and raises.