Subsequent Environmental Document
A subsequent environmental document is required when:
- Substantial changes are proposed for a project that has undergone CEQA compliance analysis and review in a previous environmental document.
- Changes constitute a new, potentially significant environmental impact(s)
- Changes substantially increase the severity of previously identified/analyzed environmental impacts.
- Reference: 14 CCR Section 15162(a)(1)
- Substantial changes occur with respect to the circumstances under which the project is to be undertaken that involve new potentially significant impacts or may substantially increase the severity of previously identified ones.
- Reference: 14 CCR Section 15162(a)(2)
- New information of substantial importance shows that:
- The project will have one or more significant impacts not discussed in the previous environmental document.
- Potentially significant impacts previously examined will be substantially more severe than shown in the previous environmental document.
- Mitigation measures or alternatives previously found not to be feasible have become feasible and would substantially reduce one or more significant impacts resulting from project implementation, but the project proponent(s) declines to adopt them.
- Mitigation measures or alternatives that are considerably different from those analyzed in the previous environmental document(s) would substantially reduce one or more potentially significant impacts, but the project proponent(s) declines to adopt them.
- Reference: 14 CCR Section 15162(a)(3)
Supplemental Environmental Document
A supplemental EIR may be prepared and circulated when:
- Any of the conditions requiring the preparation of a subsequent EIR and only minor additions or changes would be necessary to make the previous EIR adequately apply to the project in the changed situation.
- The supplement to the EIR contains only the information necessary to make the previous EIR adequate for the project as revised.
- Reference: 14 CCR Section 15163(a)
Addendum to an Environmental Document
An addendum to an environmental document may be prepared when:
- Changes or additions are necessary and a subsequent environmental document is not required.
- An addendum may be prepared if only minor technical changes or additions are necessary
- The addendum need not be circulated for review and comment, however, the decision-making body shall consider the addendum with the environmental document prior to making a decision on the project
- Reference: 14 CCR Section 15164