A. The order authorizing the establishment of the underground conversion service area shall authorize each public service corporation or public agency whose overhead electric or communication facilities are to be converted to charge the underground conversion costs to each lot or parcel of real property within the underground conversion service area. The underground conversion costs shall be in an amount sufficient to repay the public service corporation or public agency for the following:

1. The remaining undepreciated original costs of the existing overhead electric and communication facilities to be removed as determined in accordance with the uniform system of accounts applicable to the public service corporation or public agency.

2. The actual costs of removing such overhead electric and communication facilities, less the salvage value of the facilities removed.

3. The contribution in aid of construction which the public service corporation or public agency would require under its rules and regulations applicable to underground conversion service areas.

4. If not paid in full as provided in section 40-348, the actual cost of converting to underground the facilities from the public place to the point of delivery on the lot or parcel owned by each owner receiving service, in the case of an electric public service corporation or public agency, or to the connection point within the house or structures, in the case of a communication corporation, less any credit which may be given such owner under the line extension policy of the public service corporation or public agency then in existence.

5. If property belonging to the United States, this state, county, city, school district or any other political subdivision or institution of the state or county is included in the underground conversion service area, and they do not voluntarily assume such costs, the underground conversion cost applicable to such property shall be charged pro rata against the remaining property included within the underground conversion service area.

B. The cost incurred in placing underground the facilities in public places shall be apportioned among the owners of property within the area on the basis of relative size of each parcel by the corporation commission, the board of supervisors or the city or town council. The underground conversion cost, as determined by the method prescribed in subsection A shall not exceed the estimated costs indicated in the joint report prepared by the public service corporation or public agency pursuant to subsection D of section 40-342 and, may be paid in cash by the property owners within sixty days from the date the overhead facilities are removed from public places, or may be paid by a uniform plan applicable to all property owners not paying within the sixty-day period in equal periodic installments over a reasonable period of time, not exceeding fifteen years, as established by the corporation commission, the board of supervisors or the city or town council, together with interest at a rate to be determined by the corporation commission, the board of supervisors or the city or town council but not to exceed eight per cent per annum.

C. If funds become available from other public or private sources to pay all or any part of the underground conversion costs, any such funds shall be applied on a pro rata basis to reduce the underground conversion cost charged against each parcel or lot.

D. Notwithstanding the provisions of subsection B of this section, the public service corporation or public agency serving such area may by agreement with all the owners of the property in an underground conversion service area provide for reimbursement to it of the cost of such conversion on a different basis as to payment or security than that set out by the terms of this article.