Water mains will be extended for new customers on the following basis:
(a) Where the cost of the extension is to immediately be collected through assessment by the municipality against the abutting property, the procedure set forth under Sec. 66.0703, Wis. Stats. will apply, and no additional customer contribution to the Water Utility will be required.
(b) Where the municipality is unwilling or unable to make a special assessment, the extension will be made on a customer-financed basis as follows:
(1) The applicant(s) will advance as a contribution in aid of construction the total amount equivalent to that which would have been assessed for all property under Subsection (a).
(2) Part of the contribution required in Subsection (b)(l) will be refundable. When additional customers are connected to the extended main within ten (10) years of the date of completion, contributions in aid of construction will be collected equal to the amount which would have been assessed under Subsection (b)(l) for the abutting property being served. This amount will be refunded to the original contributor(s). In no case will the contributions received from additional customers exceed the proportionate amount which would have been required under Subsection (a) nor will it exceed the total assessable cost of the original extension.
(c) When a customer connects to a transmission main or connecting loop installed at Water Utility expense within ten (10) years of the date of completion, there will be a contribution required of an amount equivalent to that which would have been assessed under Subsection (a).