If the voters approve the plan, including creation of a regional fire protection service authority and imposition of taxes and benefit charges, if any, and the election results are certified, the authority is formed on the effective date as set forth in the plan or the next January 1st or July 1st, whichever occurs first. A party challenging the procedure or the formation of a voter-approved authority must file the challenge in writing by serving the prosecuting attorney of each county within, or partially within, the regional fire protection service authority and the attorney general within thirty days after the final certification of the election. Failure to challenge within that time forever bars further challenge of the authority's valid formation.