All trustees elected for any sewer district formed under the provisions of sections 249.010 to 249.420 shall furnish bond with good and sufficient sureties in favor of the district for the faithful accounting for all funds under their control. Said bond to be satisfactory to and to be approved by the circuit court; such bond shall be in the sum of not less than ten thousand dollars for each trustee. Each treasurer of a board of trustees of any district under sections 249.010 to 249.420 shall, before taking custody of any funds of the district also furnish a bond with good and sufficient sureties in favor of the district in such sum as may be determined from time to time by the board of trustees, depending upon the amount in the custody of the treasurer; such bond shall be satisfactory to and approved by the circuit court; such treasurer shall not expend or pay out any sum of money belonging to the district except upon warrants drawn and authorized by the board of trustees. The premiums on bonds above required shall be paid out of funds in the hands of the board of trustees and shall be regarded as expense of said board.