A county or municipality which proposes to enter into a contract under Article IX, Section IV, Paragraph IV of the Constitution shall, prior to entering into such contract, conduct at least one public hearing with respect to such proposed contract. Notice of such public hearing shall be given by a prominent advertisement in a newspaper of general circulation within the county or municipality. The parties proposing to enter into a contract may agree to conduct a joint public hearing in lieu of separate public hearings by each party. The notice of public hearing required in the case of a municipality may be combined with a notice of public hearing for the county within which the municipality is located.