N.H. Rev. Stat. Ann. § 38:4

Any town or village district may initially establish such a plant after 2/3 of all the voters present and voting at an annual or special meeting, duly warned in either case, have voted by ballot with the use of the checklist that it is expedient to do so. A favorable vote to establish such a plant shall create a rebuttable presumption that such action is in the public interest. If such vote is unfavorable, the question shall not be again submitted to the voters within 2 years thereafter.