The employer of each member shall submit all required school reports and all employer and employee contributions of each member due the Retirement System for payroll periods ending during the calendar month within ten (10) days of the last day of each calendar month. Any required school reports and employer and employee contribution amounts not submitted to the Retirement System after thirty (30) days from the end of the payroll month shall be subject to a monthly late charge of one and one-half percent (1 1/2%) of the unpaid balance to be paid by the employer to the Retirement System compounding monthly for each month payment is not received. The System may waive late fees for good cause shown.