Cal. Pub. Res. Code § 25524.5

The commission shall not certify any facility which adds generating capacity to a potential multiple-facility site in excess of the maximum allowable capacity established by the commission pursuant to Section 25516.5, unless the commission finds that exceeding the maximum allowable capacity will not increase adverse environmental impacts or create technological, seismic, or other difficulties beyond those already found acceptable in the commission’s findings on the notice for that site pursuant to Sections 25516 and 25516.5.