N.H. Rev. Stat. Ann. § 310-A:214

If, in the determination of the board, another state grants reciprocity to residents of this state and is deemed to have state requirements equal to or exceeding those of this state, the board may enter into a reciprocity agreement allowing applicants who are certified under the laws of such other state to obtain a license as a septic system evaluator in this state upon such terms and conditions as may be determined by the board.