If a project falls within any of the categorical exemption classes, the Lead Agency must next evaluate whether any exception to the exemptions apply. These exceptions to the exemptions define circumstances that override or negate the agency’s ability to use a categorical exemption. In other words, if an exception applies, then the project no longer qualifies for a categorical exemption. The exceptions are described in Public Resources Code Section 21084(c), (d), and (e) and State CEQA Guidelines Section 15300.2. These exceptions apply (and therefore a categorical exemption does not apply) where:
- The project is located in a sensitive environment such that the project may impact an officially mapped and designated environmental resource of hazardous or critical concern;1
- The cumulative effect of successive projects of the same type in the same place, over time, is significant;
- The project may have a significant environmental impact due to unusual circumstances;
- The project may damage scenic resources (i.e. trees, historic buildings, or rock outcroppings) within an official state scenic highway;
- The project is located on a listed hazardous waste site; or
- The project may a cause substantial adverse change in the significance of a historical resource.
If any of these exceptions apply to the project or the project site, the agency or governmental unit cannot use a categorical exemption and must instead proceed with environmental review under CEQA.
- This exception only applies to Class 3 (existing facilities), Class 4 (minor alterations to land), Class 5 (minor alterations in land use limitations), Class 6 (information collection), or Class 11 (accessory structures) exemptions. This exception does not apply to any other categorical exemption.