On behalf of each unit in the Department, the Secretary, with the approval of the Governor, may waive the provisions of this article requiring competitive bids if: The purchase is to be made from or the contract is to be made with the federal or any state government or any of their agencies or political subdivisions; The public exigency requires the immediate delivery or use of the supplies or services; or Only one source of supply is available. For purposes of this section, public exigency means an emergency caused by an act of God, natural disaster, catastrophe, or other similar event or public disorder, when the health, safety, or welfare of the citizens of the State would be jeopardized by a delay caused by the requirements of competitive bidding.