(a) The county legislative body may authorize the committee to assume the functions of any or all of the following special committees or the county legislative body may by resolution create:

(1) A budget committee;

(2) An investment committee; or

(3) A purchasing committee.

(b)

(1) Except as provided in subdivision (b)(2), upon creation, the special committees shall be composed of a minimum of five (5) members appointed by the county legislative body. The members of such committee need not be members of the county legislative body.

(2)

(A) Notwithstanding subdivision (b)(1), in counties having the following populations, according to the 1990 federal census or any subsequent federal census, special committees shall be composed of five (5) members:

(B) Notwithstanding subdivision (b)(1), in counties having a population of not less than seventeen thousand two hundred fifty (17,250) nor more than seventeen thousand five hundred fifty (17,550), according to the 1990 federal census or any subsequent federal census, the budget committee shall be composed of six (6) members.

(c) The director shall be the ex officio secretary of each such committee.

(d) The budget committee shall establish and approve policies, forms and documents, procedures, and regulations necessary for the preparation of the annual operating and capital improvement budgets.

(e) The investment committee shall establish and approve policies and procedures for cash management and investing idle cash funds in various investments as prescribed by law.

(f) The purchasing committee shall establish and approve policies and procedures for the purchasing of all supplies, equipment or goods for the county.