The obligations imposed on the district by the contracts or agreements provided for in § 87-12 shall be guaranteed by Montgomery and Prince George's Counties in the proportions agreed to in the allocations approved under § 87-12. The guarantee shall be made by resolution of the county councils of Montgomery County and Prince George's County and shall be evidenced by the endorsement of the guarantee on the face of the contract or agreement, signed on behalf of each county by the secretary or clerk of the county council or by any officer designated by the county council. (Mont. Co. Code 1965, § 72-13; 1965, ch. 870, § 1; 1992, ch. 22, § 1.)