(a) The board shall keep or cause to be kept separate books of account of each light plant, water plant, or sewerage system under its control and operation and for that purpose may employ such clerical help, bookkeepers, and accountants as may be necessary.
(b) The books of accounts shall be audited annually by a certified public accountant, licensed and engaged in the practice of accountancy in the State of Arkansas, who shall make a detailed report of his audit and file one (1) copy with the secretary of the board and one (1) copy with the city clerk or recorder of the city or town wherein the board shall be. The expenses of such audits shall be paid by the boards of public utilities from the funds derived by them from the operation of the plants or sewerage systems.