(a) In counties having a population of more than 150,000 the county board, when requested by the County Treasurer, shall designate one or more banks, savings and loan associations, savings banks, or credit unions in which the funds and other public moneys in the custody of the County Treasurer may be kept and when a bank, savings and loan association, savings bank, or credit union has been designated as a depository it shall continue as such until 10 days have elapsed after a new depository is designated and has qualified by furnishing the statements of resources and liabilities as is required by this Section. When a new depository is designated, the county board shall notify the sureties of the County Treasurer of that fact, in writing, at least 5 days before the transfer of funds. The County Treasurer shall be discharged from responsibility for all funds and moneys which he deposits in a depository so designated while such funds and moneys are so deposited.
     No bank, savings and loan association, savings bank, or credit union shall receive public funds as permitted by this Section, unless it has complied with the requirements established pursuant to Section 6 of “An Act relating to certain investments of public funds by public agencies”, approved July 23, 1943, as now or hereafter amended.
     (b) In addition to any other investments or deposits authorized under this Code, counties are authorized to invest the funds and public moneys in the custody of the County Treasurer in accordance with the Public Funds Investment Act.