Cities and towns owning their own sewer systems shall have a lien for delinquent and unpaid rates and charges for sewer service, penalties levied pursuant to RCW 35.67.190, and connection charges, including interest thereon, against the premises to which such service has been furnished or is available, which lien shall be superior to all other liens and encumbrances except general taxes and local and special assessments. The city or town by ordinance may provide that delinquent charges shall bear interest at not exceeding eight percent per annum computed on a monthly basis: PROVIDED, That a city or town using the property tax system for utility billing may, by resolution or ordinance, adopt the alternative lien procedure as set forth in RCW 35.67.215.