The governing body of any county in which a sanitary district has been or may be created by general or special law shall have the power to issue bonds to satisfy improvements to water or sewerage systems mandated by the State Water Control Board, pursuant to the Federal Water Pollution Control Act, as amended (P.L. 92-500). The principal and interest on bonds issued under this section shall be paid by the governing body exclusively from revenues and receipts from the water or sewerage system which is to be improved. For the purposes of this section, the term “mandated” shall also mean any agreement between a governing body and the State Water Control Board to come into compliance with the requirements of the State Water Control Law. Issuance of such bonds shall be subject to the conditions or limitations of this article; however, no bond referendum shall be required for bonds to be issued pursuant to this section. The sections of this article pertaining to election requirements and procedures shall not be applicable where bonds are to be issued for the purposes set forth herein. In addition, the provisions of §§ 21-137.2 and 21-138, authorizing an annual tax to be levied upon all the property in the district in order to pay the principal and interest due on the bonds, shall not be applicable to bonds issued under this section. All bonds issued under the provisions of this section shall contain a statement on their face substantially to the effect that neither the faith and credit of the Commonwealth nor the faith and credit of any county, city, town or other subdivision of the Commonwealth are pledged to the payment of the principal of or the interest on such bonds. The issuance of revenue bonds under the provisions of this section shall not directly or indirectly or contingently obligate the Commonwealth or any county, city, town or other subdivision of the Commonwealth to levy any taxes whatever therefor or to make any appropriation for their payment except from the funds pledged under the provisions of this section.