(a) If a project consists solely of compliance with a performance standard or treatment requirement imposed by an agency listed in Section 21159.4, the lead agency for the compliance project shall, to the greatest extent feasible, utilize the environmental analysis required pursuant to subdivision (a) of Section 21159 in the preparation of a negative declaration, mitigated negative declaration, or environmental impact report on the compliance project or in otherwise fulfilling its responsibilities under this division. The use of numerical averages or ranges in an environmental analysis shall not relieve a lead agency of its obligations under this division to identify and evaluate the environmental effects of a compliance project.
(b) If the lead agency determines that an environmental impact report on the compliance project is required, the lead agency shall prepare an environmental impact report which addresses only the project-specific issues related to the compliance project or other issues that were not discussed in sufficient detail in the environmental analysis to enable the lead agency to fulfill its responsibilities under Section 21100 or 21151, as applicable. The mitigation measures imposed by the lead agency for the project shall relate only to the significant effects on the environment to be mitigated. The discussion of alternatives shall be limited to a discussion of alternative means of compliance, if any, with the rule or regulation.