(1) The general manager shall be the chief executive and operating officer of the joint agency. The general manager shall exercise the management of the properties and business of the joint agency and its employees. The general manager shall direct the enforcement of all resolutions, rules, and regulations of the board of commissioners, and shall enter into contracts as necessary under the general control and direction of the board of commissioners. The general manager shall serve at the pleasure of the board of commissioners.

  (2) Subject to the approval of the board of commissioners, the general manager may appoint the officers, employees, and agents necessary to carry out the general purposes of the joint agency. If the joint agency operates a project described in section 5(1), the general manager shall classify all the offices, positions, and grades of regular employment required in the project.