1. The total amount of any bonds issued pursuant to sections 204.251 to 204.257 for improvements to the subdistrict of the common sewer district shall not exceed ten percent of the assessed valuation of all taxable tangible property, as shown by the last completed property assessment for state or local purposes, within the common sewer district.

2. Such bonds shall be signed by the president of the board of trustees and attested by the signature of the secretary of the board of trustees with the seal of the district affixed thereto. The interest coupons may be executed by affixing thereon the facsimile signature of the secretary of the district. The bonds may be sold under the same conditions as are provided for the sale of county road bonds.

3. All bonds issued under sections 204.251 to 204.257 shall be registered in the office of the state auditor as provided by law for the registration of bonds of cities and in the office of the secretary of the board of trustees of the district in a book kept for that purpose for registry, shall show the number, date, amount, date of sale, name of the purchaser and the amount for which the bond was sold. The moneys of the common sewer district shall be deposited by the treasurer of the common sewer district in such bank or banks as shall be designated by order of the board of trustees and the secretary of the common sewer district shall charge the treasurer therewith and the moneys shall be drawn from the treasury upon warrants issued by the common sewer district for the purposes for which the bonds were issued.