One commissioner from each of the counties shall be appointed for one year, one for two years, and one for three years, and one from each county shall be appointed annually thereafter for a term of three years. The person appointed a commissioner, but who shall not reside in any of such counties, shall be appointed for a term of three years. Upon a vacancy occurring in the office of any commissioner for any reason, his successor shall be appointed for the unexpired term only. The commissioners shall serve without remuneration.
N.J.S. § 32:12-3