Until the 121st day after the effective date of this section, any objectives, criteria and procedures adopted by public agencies in compliance with this division shall govern the evaluation of projects defined in subdivisions (a) and (b) of Section 21065 and the preparation of environmental impact reports on such projects when required by this division. Any environmental impact report which has been completed or on which substantial work has been performed on or before the 121st day after the effective date of this section, if otherwise legally sufficient, shall, when completed, be deemed to be in compliance with this division and no further environmental impact report shall be required except as provided in Section 21166.