PRC §21158: (a) A focused environmental impact report is an environmental impact report on a subsequent project identified in a master environmental impact report.

(a) A focused environmental impact report is an environmental impact report on a subsequent project identified in a master environmental impact report. A focused environmental impact report may be utilized only if the lead agency finds that the analysis in the master environmental impact report of cumulative impacts, growth inducing impacts, and irreversible significant effects on the environment is adequate for the subsequent project. The focused environmental impact report shall incorporate, by reference, the master environmental impact report and analyze only the subsequent project’s additional significant effects on the environment, as defined in subdivision (d), and any new or additional mitigation measures or alternatives that were not identified and analyzed by the master environmental impact report. (b) The focused environmental impact report need not examine those effects which the lead agency finds were one of the following: (1) Mitigated or avoided pursuant to paragraph (1) of subdivision (a) of Section 21081 as a result of mitigation measures identified in the master environmental impact report which will be required as part of the approval of the subsequent project. (2) Examined at a sufficient level of detail in the master environmental impact report to enable those significant environmental effects to be mitigated or avoided by specific revisions to the project, the imposition of conditions, or by other means in connection with the approval of the subsequent project. (3) Subject to a finding pursuant to paragraph (2) of subdivision (a) of Section 21081. (c) A focused environmental impact report on any subsequent project shall analyze any significant effects on the environment where substantial new or additional information shows that the adverse environmental impact may be more significant than was described in the master environmental impact report. The substantial new or additional information may also show that mitigation measures or alternatives identified in the master environmental impact report, which were previously determined to be infeasible, are feasible and will avoid or reduce the significant effects on the environment of the subsequent project to a level of insignificance. (d) For purposes of this chapter, “additional significant effects on the environment” are those project specific effects on the environment which were not addressed as significant effects on the environment in the master environmental impact report. (e) Nothing in this chapter is intended to limit or abridge the ability of a lead agency to focus upon the issues that are ripe for decision at each level of environmental review, or to exclude duplicative analysis of environmental effects examined in previous environmental impact reports pursuant to Section 21093.