Any vacancy in a sanitary district board shall be filled by the county commissioners until the next election for sanitary district board members. If the district is located in more than one county, the vacancy shall be filled by the county commissioners of the county from which the vacancy occurred. (1935, c. 357, s. 2; 1957, c. 1357, s. 1; 1981, c. 186, s. 2; 1983, c. 891, s. 2.)