The Council, for the purpose of making any of the improvements provided in this Division, or providing the governmental services or municipal functions, or for the maintenance and operation of the facilities, or systems within the defined areas, shall have full power and authority to borrow upon the faith and credit of the County such sum or sums as may be needed for the purposes above mentioned, to fix the maturity or maturities of any such debt, the interest rate or rates, not exceeding six percent (6%) per annum, and manner and place of payment, and in each instance to issue its bonds or notes or other evidences of indebtedness for the amount of monies so borrowed. The bonds, notes or other evidences of indebtedness shall be issued in groups or series, each such group or series to be appropriately identified with the improvement for which the money is being borrowed. The bonds, notes or other evidences of indebtedness may be sold by the Council from time to time at public sale or by private negotiation, notwithstanding the provisions of Section 10 of Article 31 of the Code of Public General Laws of Maryland (1957 Edition), as amended. None of the bonds, notes or evidences of indebtedness shall be issued to mature over a longer period than thirty (30) years from the date of issuance, or the probable useful life of the improvements, or undertaking with respect to which they are to be issued. They shall be issued on an annual serial maturity plan so arranged as to correspond as nearly as possible in amounts with the aggregate amounts of special assessments as above provided. The Council shall, by a proper ordinance in each case, provide for the issuance of the bonds, notes or other evidences of indebtedness and for the liquidation thereof and the interest thereon by the application of the receipts of the special assessments with respect to which the bonds, notes or evidences of indebtedness are issued. The Council shall, also by the ordinance provide, in each case, that in the event the proceeds of the collection of such special assessments are in any year insufficient for the purpose of paying the principal and interest maturities of any such bonds, notes or evidences of indebtedness, such deficiency shall be made up by the County from the proceeds of unlimited ad valorem taxes levied upon all assessable property within the corporate limits of the County subject to unlimited taxation thereby. Any bond issued pursuant to the authority of this Division and the interest payable thereon and the income derived therefrom in the hands of the holders thereof from time to time shall be, and is declared to be, exempt from State, County and municipal taxation of every kind and nature whatsoever in this State.