The governing body of any locality is authorized to provide by resolution or ordinance for the defeasance of any bonds of the locality now or hereafter outstanding, to the extent that the defeasance of such bonds is not otherwise provided for in the resolution, ordinance, indenture or other document governing the issuance of such bonds. Bonds to be defeased pursuant to this section shall be deemed defeased and no longer outstanding when there has been established with a bank or trust company designated by the locality an escrow or sinking fund consisting of cash and noncallable obligations of, or unconditionally guaranteed by, the United States of America or noncallable obligations of, or unconditionally guaranteed by, the Commonwealth in an amount which together with interest to be earned on such obligations will be sufficient to pay all bonds to be defeased either at maturity or upon redemption; however, if such bonds are to be defeased either at maturity or upon redemption, notice of the redemption of such bonds shall have been duly given or irrevocable instructions to redeem such bonds shall have been given by the locality. Any escrow fund established pursuant to this section shall be irrevocably pledged to the payment of the bonds to be defeased and shall be used solely to pay such bonds at maturity or upon earlier redemption. It is the intent that any escrow fund established pursuant to this section shall constitute a special fund for the payment of the defeased bonds and that the defeased bonds shall not be included for the purpose of determining any limitation upon the amount of indebtedness of the locality which is imposed by law. The owners of any outstanding bonds to be defeased shall be divested of all rights and security relating to the bonds, except the right to payment due to principal, premium, if any, and interest, which shall be paid solely from the escrow fund.