Prior to the release or expiration of bond, the Council will request the Administrative Officer to certify that he or she was notified by the subdivider to witness the installation of required improvements at key times so as to be able to certify that all required improvements were properly installed and that neither the subdivision as built nor improvements installed deviate from the approved final plat. Should the required improvements not be completed within the duration of the bond, the subdivider may request the Council for an extension of time for the installation of the balance of improvements. Should such request be granted, the subdivider shall deposit with the city a surety bond for the length of extension granted. Bond shall be approved as to form and type by the City Attorney, and as to adequacy of amount by Engineer.