The Commission shall consist of seven members. Two members shall be appointed by the County Council of Richland County for terms of three and four years; two members shall be appointed by the Lexington County Council for terms of two and five years; two members shall be appointed by the Mayor and City Council of Columbia for terms of one and six years; one member shall be appointed for an initial term of one year by the Lexington County Council, the Richland County Council and the Mayor and City Council of Columbia. Thereafter, all appointments shall be for a term of six years and until their successors are appointed and qualify.