Forty percent of the cost of operation of the authority shall be paid by the county and the remaining cost shall be paid by the aforementioned cities and towns. On or before January 15 of each year, the authority shall certify to the appropriate official of each city and town what the proportionate amount of the funding of the authority shall be for the city or town, such amount to be based on the ratio of the population of the city or town to the total population of the county. Each city or town shall remit its proportionate amount on or before March 1 of each year. The authority shall then deposit such monies in a special fund in the county treasury to the credit of the authority. All other funds otherwise coming into the hands of the authority shall likewise be deposited in such fund. The ordinary and necessary operating expenses of the authority, including the expenses of its members and the salaries and expenses of employees of the authority shall be paid out of authority funds. The authority shall be audited as are other state and county agencies by the Department of Examiners of Public Accounts.