(1) The district may borrow money for corporate purposes and issue its general obligation bonds therefor and shall annually levy a tax on the taxable value of the taxable property in the district sufficient to pay the interest and principal on the bonds. Such levy shall be known as the bond tax levy of the district. The district shall also annually levy a tax on the taxable value of the taxable property in the district for the purpose of creating a sinking fund for the maintenance and repairing of any sewer or water system or electric lines and conduits in the district, for the payment of any hydrant rentals, for the maintenance and repairing of any sidewalks, public roads, streets, and highways, public waterways, docks, or wharfs, and related appurtenances in the district, for the cost of operating any street lighting system for the public streets and highways within the district, for the building, construction, improvement, or replacement of facilities or systems when necessary to remove or alleviate an existing threat to public health and safety affecting no more than one hundred existing homes, for the cost of building, acquiring, maintaining, and operating public parks, playgrounds, and recreational facilities, or, when permitted by section 31-727, for contracting with other sanitary and improvement districts for building, acquiring, maintaining, and operating public parks, playgrounds, and recreational facilities for the joint use of the residents of the contracting districts, or for the cost of any other services for which the district has contracted or to make up any deficiencies caused by the nonpayment of any special assessments. Such levy shall be known as the operating levy of the district. On or before September 20 of each year, the clerk of the board shall certify the tax to the county clerk of the counties in which such district is located in order that the tax may be extended upon the county tax list. Nothing contained in this section shall authorize any district which has been annexed by a city or village to levy any taxes within or upon the annexed area after the effective date of the annexation if the effective date of the annexation is prior to such levy certification date of the district for the year in which such annexation occurs.
(2) The county treasurer of the county in which the greater portion of the area of the district is located shall be ex officio treasurer of the sanitary and improvement district and shall be responsible for all funds of the district coming into his or her hands. He or she shall collect all taxes and special assessments levied by the district and deposit the same in a bond sinking fund for the payment of principal and interest on any bonds outstanding.
(3) Except as provided in subsection (5) of this section, the trustees or administrator of the district may authorize the clerk or appoint an independent agent to collect service charges and all items other than taxes, connection charges, special assessments, and funds from sale of bonds and warrants, but all funds so collected shall, at least once each month, be remitted to the treasurer to be held in a fund, separate from the general fund or construction fund of the district, which shall be known as the service fee fund of the district. The trustees or administrator may direct the district's treasurer to disburse funds held in the service fee fund to maintain and operate any service for which the funds have been collected or to deposit such funds into the general fund of the district.
(4) The treasurer of the district shall not be responsible for such funds until they are received by him or her. The treasurer shall disburse the funds of the district only on warrants authorized by the trustees or the administrator and signed by the chairperson and clerk or the administrator.
(5) If the average weekly balance in the service fee fund of a district for a full budget year does not exceed five thousand dollars, the trustees or administrator of the district may authorize the clerk to establish an interest-bearing checking account in the name of the district to be maintained as the district service fee fund and the district's treasurer shall disburse the balance of funds held in the service fee fund of the district to the clerk for deposit into the district service fee fund. Following the creation of the district service fee fund, all funds required to be deposited into the service fee fund shall be deposited into the district service fee fund and all disbursements which may lawfully be made from the service fee fund may be made from the district service fee fund as directed or approved by the trustees or the administrator.