PRC §21157.5: (a) A proposed mitigated negative declaration shall be prepared for any proposed subsequent project if both of the following occur: (1) An initial study has identified potentially new or additional si

(a) A proposed mitigated negative declaration shall be prepared for any proposed subsequent project if both of the following occur: (1) An initial study has identified potentially new or additional significant effects on the environment that were not analyzed in the master environmental impact report. (2) Feasible mitigation measures or alternatives will be incorporated to revise the proposed subsequent project, before the negative declaration is released for public review, in order to avoid the effects or mitigate the effects to a point where clearly no significant effect on the environment will occur. (b) If there is substantial evidence in light of the whole record before the lead agency that the proposed subsequent project may have a significant effect on the environment and a mitigated negative declaration is not prepared, the lead agency shall prepare an environmental impact report or a focused environmental impact report pursuant to Section 21158.