(a) General rule.--Irrespective of the type of contract, no contract shall be effective until executed by all necessary Commonwealth officials as provided by law.

(b) Certain contracts.--Those Statewide requirements contracts where the total dollar purchasing amount, based upon estimated quantities, is in excess of $1,000,000 shall not be effective unless first approved by the State Treasurer. The $1,000,000 amount shall be adjusted each year by the department to reflect the annual percentage change in the Composite Construction Cost Index of the United States Department of Commerce occurring in the one-year period ending December 31 each year.