Yes. The OC Fairgrounds must follow the California Environmental Quality Act (CEQA). CEQA requires proposed development to be evaluated to determine significant effects on the environment of a project, to identify alternatives to the project, and to indicated the manner in which those significant effects can be mitigated or avoided.

CEQA is created by law. See California Public Resources Code starting at Section 21000.

CEQA is carried out using regulations created by the State. See California Code of Regulation, Title 14 Natural Resources, Division 6 Resource Agency, Chapter 3 Guidelines for Implementation of the California Environmental Quality Act.

Learn more about CEQA from the California League of Cities

https://www.cacities.org/Resources-Documents/Education-and-Events-Section/Planners-Institute/2015-Handouts/CEQA-Basics-Everything-a-New-Planning-Commissioner