Said connection fees shall be payable in the following manner:
Sixty percent (60%) shall be paid at the time of approval of the final plat of subdivision, resubdivision, planned unit development, commercial or industrial development
The balance may be paid in equal installments on issuance of the building permits for each residential, commercial or industrial unit; provided, however, that in the event said lands are the subject matter of an annexation agreement, said sums shall be paid at the times and in the manner provided in said annexation agreement.
In the case of a commercial or industrial development, after the development has been fully occupied for a year, any difference owed to the Village as a result of the actual average daily gallon usage of water exceeding seventy five percent (75%) of the estimated daily gallon usage of water shall be paid within sixty (60) days of the determination of the difference. If the seventy five percent (75%) of the estimated daily gallon usage of water exceeds the actual average daily gallon usage of water, any difference in resulting fees shall be paid to the developer within sixty (60) days of the determination of the difference.