(1) Any bonds issued hereunder and at any time outstanding may at any time and from time to time be refunded by the county, but only with the approval of the Authority being first obtained, by the issuance of its refunding bonds in such amounts as the county board may deem necessary but not exceeding an amount sufficient to refund the principal of the bonds to be refunded, together with any interest then or thereafter to become due (prior to the date when all outstanding bonds shall be paid) and any premium, expenses and commissions necessary to be paid in connection therewith.

(2) Any such refunding may be effected whether the bonds to be refunded have matured or shall thereafter mature, either by sale of the refunding bonds and the application of the proceeds for the payment of the bonds to be refunded, or by exchange of the refunding bonds for the bonds to be refunded thereby; provided, that the holders of any bonds to be refunded shall not be compelled without their consent to surrender their bonds for payment or exchange prior to the date on which they are payable, or, if they are called for redemption, prior to the date on which they are by their terms subject to redemption.

(3) Except as provided in paragraph (4) of this section, all refunding bonds issued under the authority of this article shall be payable in the same manner and under the same terms and conditions as are herein provided for the issuance of bonds. The power to issue refunding bonds herein granted includes the power to effect a refunding in advance of the maturity or earliest redemption date of the bonds being refunded; provided, that no refunding shall be effected more than eight years prior to the maturity or earliest redemption date of the bonds being refunded.

(4) Any loan agreement made for the purpose of securing refunding bonds may provide:

(a) That any leasehold estate granted thereby shall become effective as of the occasion of the termination of any existing leasehold estate;

(b) That prior to the time when lease rental payments become due, the then holder of any leasehold estate created by the loan agreement securing the outstanding bonds shall be unconditionally obligated to pay, as and when they become due and payable, amounts sufficient to pay the principal, interest and redemption premiums, if any, on the refunding bonds;

(c) For an irrevocable agreement on the part of the county to call for redemption on the earliest available redemption date all of the bonds to be refunded which do not mature prior to such date; and

(d) That the proceeds derived from the sale of the refunding bonds and any other funds that may be required shall be deposited forthwith in a trust account and invested in direct obligations of, or obligations guaranteed by, the United States of America, the corpus of which shall be applied to the payment of the principal, interest and redemption premium, if any, of the bonds being refunded. Any agreement between the county and the trustee of the trust account established pursuant to this paragraph may prescribe that income earned from investments of the corpus thereof be used or applied for any of the following purposes: (i) to the payment of the interest on the outstanding bonds; (ii) to the payment of interest on the refunding bonds until the redemption of the outstanding bonds; (iii) partially in accordance with (i) hereof and partially in accordance with (ii) hereof; and (iv) added in whole or in part to the corpus (and used in accordance with the provisions hereof relating to the use of corpus), with the balance of income, if any, being applied in accordance with any of (i), (ii) or (iii) hereof.

(5) In the exercise of the powers herein granted to effect advance refundings, any county board may, but shall not be required to, avail itself of any of the provisions of the Advanced Refunding Act [§§ 11-21-10 to 11-21-80].