(a) Partial, progress or interim payments: all partial, progress or interim payments or monies owed contractors shall be paid when due and payable under the terms of the contract. If they are not paid within thirty (30) calendar days from the day they were due and payable, then they shall bear interest from the due date at the rate of one percent (1%) per month until fully paid.

(b) Final payments: The final payment of all monies owed contractors shall be due and payable:

(i) At the completion of the project or after the work has been substantially completed in accordance with the terms and provisions of the contract;

(ii) When the owner beneficially uses or occupies the project except in the case where the project involves renovation or alteration to an existing facility in which the owner maintains beneficial use or occupancy during the course of the project; or

(iii) When the project is certified as having been completed by the architect or engineer authorized to make such certification, whichever event shall first occur.

If the contractor is not paid in full within thirty (30) calendar days from the first occurrence of one (1) of the above-mentioned events, then the final payment shall bear interest from the date of such first occurrence at the rate of one percent (1%) per month until fully paid.

In no event shall the final payment due the contractor be made until the consent of the contractor’s surety has been obtained in writing and delivered to the proper contracting authority.