7-13-4207. Special fund for sewer rentals. (1) The funds received from the collection of sewer rentals shall be kept as a separate and distinct fund by the city treasurer, subject only to disbursement by order of the council.

(2) This fund shall be used for:

(a) the payment of the cost of management, maintenance, operation, and repair of the sewage system, including treatment and disposal works;

(b) for the creation of a sinking fund for the retirement of any indebtedness; and

(c) for the payment of interest on any such indebtedness.

(3) Any surplus in such fund may be used for the enlargement or replacement of the same and for the payment of the interest on any debt incurred for the construction of such sewage system, including sewage pumping, treatment, and disposal works, and for retiring such debt but shall not be used for the extension of a sewage system to serve unsewered areas or for any purpose other than one or more of those specified above.