(a) As used in this Code section, the term:

(1) "Contractor" means a person having a direct contract with the owner.

(2) "Lower tier subcontractor" means a person other than a contractor having a direct contract with a subcontractor.

(3) "Owner" means the state, any county, municipal corporation, authority, board of education, or other public board, public body, department, agency, instrumentality, or political subdivision of the state.

(4) "Owner's authorized contract representative" means the architect or engineer in charge of the project for the owner or such other contract representative or officer as designated in the contract documents as the party representing the owner's interest regarding administration and oversight of the project.

(5) "Subcontractor" means a person other than an owner having a direct contract with the contractor.

(b) In any public works construction contract entered into on or after July 1, 2001, with an owner, as defined in paragraph (3) of subsection (a) of this Code section, such contract shall provide for the following:

(1) After work has commenced at the construction site, progress payments to be made on some periodic basis, and at least monthly, based on the value of work completed as may be provided in the contract documents plus the value of materials and equipment suitably stored, insured, and protected at the construction site and at the owner's discretion such materials and equipment suitably stored, insured, and protected off site at a location approved by the owner's authorized contract representative when allowed by the contract documents, less retainage; and

(2) (A) Retainage to a maximum of 10 percent of each progress payment; provided, however, when 50 percent of the contract value including change orders and other additions to the contract value provided for by the contract documents is due and the manner of completion of the contract work and its progress are reasonably satisfactory to the owner's authorized contract representative, the owner shall withhold no more retainage. At the discretion of the owner and with the approval of the contractor, the retainage of each subcontractor may be released separately as the subcontractor completes his or her work.

(B) If, after discontinuing the retention, the owner's authorized contract representative determines that the work is unsatisfactory or has fallen behind schedule, retention may be resumed at the previous level. If retention is resumed by an owner, the contractor and subcontractors shall be entitled to resume withholding retainage accordingly.

(C) At substantial completion of the work or such other standard of completion as may be provided in the contract documents and as the owner's authorized contract representative determines the work to be reasonably satisfactory, the owner shall, within 30 days after invoice and other appropriate documentation as may be required by the contract documents are provided, pay the retainage to the contractor. If at that time there are any remaining incomplete minor items, an amount equal to 200 percent of the value of each item as determined by the owner's authorized contract representative shall be withheld until such item or items are completed. The reduced retainage shall be shared by the contractor and subcontractors as their interests may appear.

(D) The contractor shall, within ten days from the contractor's receipt of retainage from the owner, pass through payments to subcontractors and shall reduce each subcontractor's retainage in the same manner as the contractors retainage is reduced by the owner; provided, however, that the value of each subcontractor's work complete and in place equals 50 percent of his or her subcontract value, including approved change orders and other additions to the subcontract value, provided, further, that the work of the subcontractor is proceeding satisfactorily and the subcontractor has provided or provides such satisfactory reasonable assurances of continued performance and financial responsibility to complete his or her work including any warranty work as the contractor in his or her reasonable discretion may require, including, but not limited to, a payment and performance bond.

(E) The subcontractor shall, within ten days from the subcontractor's receipt of retainage from the contractor, pass through payments to lower tier subcontractors and shall reduce each lower tier subcontractor's retainage in the same manner as the subcontractors retainage is reduced by the contractor; provided, however, that the value of each lower tier subcontractor's work complete and in place equals 50 percent of his or her subcontract value, including approved change orders and other additions to the subcontract value; provided, further, that the work of the lower tier subcontractor is proceeding satisfactorily and the lower tier subcontractor has provided or provides such satisfactory reasonable assurances of continued performance and financial responsibility to complete his or her work including any warranty work as the subcontractor in his or her reasonable discretion may require, including, but not limited to, a payment and performance bond.

(c) This Code section shall not apply to:

(1) Any contracts let by the Department of Transportation of this state for the construction, improvement, or maintenance of roads or highways in this state or purposes incidental thereto; or

(2) Any contracts whose value or duration at the time of the award does not exceed $150,000.00 or 45 days in duration.

(d) Contract and subcontract provisions inconsistent with the benefits extended to contractors, subcontractors, and lower tier subcontractors by this Code section shall be unenforceable; provided, however, that nothing in this Code section shall render unenforceable any contract or subcontract provisions allowing greater benefits to be extended to such contractors, subcontractors, or lower tier subcontractors, the provisions and benefits of this Code section being minimal only.

(e) Nothing shall preclude a payor under this Code section, prior to making a payment, from requiring the payee to submit satisfactory evidence that all payrolls, material bills, and other indebtedness connected with the work have been paid.