The word substantial, is found in the State CEQA Guidelines Appendix G 28 times in almost every issue area. What does substantial really mean when evaluating environmental impacts? What about wasteful, excessive, adequate, or acceptable? And it is not just in Appendix G—how do we know if something has been substantially mitigated or is consistent with an adopted plan? These are all words used to determine a project’s impact, but none of them are clearly defined. How can we measure something when no obvious quantitative threshold exists?

Using multiple choice questions with case studies, we will poll the audience and discuss strategies for evaluating subjective standards. Lessons can be gleaned from how objective design standards are created, as they provide a framework for bringing objectivity to subjective topics, analogous to what may be required under CEQA. The process for creating goals, standards, or thresholds for topics outside of CEQA without clear guiding metrics will be examined, providing examples to help work through these murky CEQA impact questions. In conversation with experts, including an advanced CEQA practitioner, an air quality and energy specialist, and a veteran urban designer, this panel will discuss industry standards, precedent-setting court cases, and resources to providesession attendees with insights, tips, and best practices to tackle measuring the immeasurable.

Speakers: Liza Debies, Associate Principal, PlaceWorks; Rachel Goren, Associate, PlaceWorks; Alan Loomis, AICP, Principal, PlaceWorks; Lance Park, Senior Associate, PlaceWorks

2026 AEP Conference – Sands to Shores: Pathways to Thriving Communities, San Diego, April 24, 2026