Each year an audit must be made of the accounts of the district, and for this purpose authorized agents of a certified public accounting firm appointed by the directors must have access to all necessary papers, books and records. Upon the completion of each audit, a report must be made to the chair of the district board of directors and a copy must be sent to the municipal officers of each member municipality.   [RR 2021, c. 2, Pt. B, §294 (COR).]