(a) Towns, cities and boroughs, by vote of their respective legislative bodies, after a public hearing, may unite to form district departments of health, which shall be instrumentalities of their constituent municipalities. The affairs of any such district department of health shall be managed by a board, which shall have all the duties exercised or performed immediately prior to the effective date of the creation of such district by directors of health or boards of health of the municipalities and which shall exercise all the authority as to public health required of or conferred upon the constituent municipalities by law and shall have the powers of the district set forth in § 19a-243. Towns, cities and boroughs may, in like manner, join a district department of health previously formed with the approval of the board of such district.

(b) Each town, city and borough, which has so voted to become a part of any such district, shall, by its board of selectmen, city council or board of burgesses, appoint one person to be a member of such board. Any town, city or borough having a population of more than ten thousand inhabitants, as annually estimated by the Department of Public Health by a method comparable or similar to that used by the United States Bureau of the Census, shall be entitled to one additional representative for each additional ten thousand population or part thereof, provided no such municipality shall have more than five representatives on a district board of health. The term of office for members of the district board of health shall be three years, except that: (1) A district board of health containing only one town may elect to have one-year or three-year terms of office, and (2) during the initial formation of a board with three-year appointments, appointments shall be so made that approximately one-third of the board shall be appointed for one year, approximately one-third appointed for two years and approximately one-third appointed for three years. Members of the district board of health shall serve without compensation but shall receive their necessary expenses while in the performance of their official duties.