A substituted bond may be filed in lieu of any bond on file with the Agency pursuant to this title. The Agency shall accept and file the same if it meets the requirements established by the Agency and is in proper form. The bond for which it is substituted shall be exonerated by the Council if the Agency finds that all of the conditions of the bond have been satisfied and no default exists as to performance upon which the bond is conditioned.
(`78 Code, § 14.12.070.)