Cal. Pub. Res. Code § 21157.6
(a) The master environmental impact report shall not be used for the purposes of this chapter if either of the following has occurred:
(b) A master environmental impact report that was certified more than five years prior to the filing of an application for the subsequent project may be used for purposes of this chapter to review a subsequent project that was described in the master environmental impact report if the lead agency reviews the adequacy of the master environmental impact report and does either of the following:
(2) Prepares an initial study and, pursuant to the findings of the initial study, does either of the following: