Priority of lien; interest; and method of payment.

The special assessments shall be payable at the time and in the manner stipulated in the resolution providing for the improvement; shall remain liens, coequal with the lien of all state, county, district, and municipal taxes, superior in dignity to all other liens, titles, and claims, until paid; shall bear interest, at a rate not to exceed 8 percent per year, or, if bonds are issued pursuant to this chapter, at a rate not to exceed 1 percent above the rate of interest at which the improvement bonds authorized pursuant to this chapter and used for the improvement are sold, from the date of the acceptance of the improvement; and may, by the resolution aforesaid and only for capital outlay projects, be made payable in equal installments over a period not to exceed 30 years notwithstanding any special act to the contrary, to which, if not paid when due, there shall be added a penalty at the rate of 1 percent per month, until paid. However, the assessments may be paid without interest at any time within 30 days after the improvement is completed and a resolution accepting the same has been adopted by the governing authority.