A $500 connection charge will be paid before 2-1-1983 and a $27 monthly surcharge will be paid, in addition to normal monthly sewage charges set forth in Ord. 975, as amended. The monthly surcharge shall be payable 1-1-1984, and each month thereafter through and including 7-1-2002; provided, the foregoing charges will not be due for any property owner who pays the sum of $2,500 on or before 2-1-1983.