Commercial permittees will, when invoiced quarterly by the City Administrator, pay a tonnage fee to the City. Fees will be assessed on a per ton basis of commercial solid waste collected within the City and deposited in disposal facilities authorized by Metro. The per ton fee will be established via a rate ordinance adopted by the City Council. Payments must be made within 30 days of the date of the invoice. Interest will accrue at one percent per month on balances that remain unpaid as of 30 days after the date of invoice, compounded daily from the due date.