The principal of, and interest and premiums, if any, on any revenue bonds issued hereunder shall be secured by a pledge of the revenues and receipts out of which the same shall be made payable and may also be payable out of proceeds from the sale of the pollution control facility acquired with proceeds of such revenue bonds, but shall not be secured by the full faith and credit or the taxing power of the state of Idaho or of any political subdivision thereof. The resolution under which the revenue bonds are authorized to be issued and any indenture executed as security for the revenue bonds, may contain any agreements and provisions respecting the maintenance of the properties covered thereby, the fixing and collection of rents for any portions thereof leased by the county to others, the creation and maintenance of special funds from such revenues and the rights and remedies available in the event of default, including the designation of a trustee, which may be a bank or trust company, the principal place of business of which may be within or without the state of Idaho, all as the board shall deem advisable and not in conflict with the provisions hereof. Each pledge and agreement made for the benefit or security of any of the revenue bonds issued hereunder shall continue effective until the principal of, and interest and premiums, if any, on the revenue bonds for the benefit of which the same were made shall have been fully paid or provision for such payment duly made. In the event of default in such payment or in any agreements of the county made as a part of the contract under which the revenue bonds were issued, whether contained in the proceedings authorizing the revenue bonds or in any indenture executed as security therefor, said payment or agreement may be enforced by suit, mandamus or the appointment of a receiver in equity, or any one (1) or more of said remedies.