NEPA Policy - Categorical Exclusion Reviews
Categorical exclusions are "a category of actions which do not individually or
cumulatively have a significant effect on the human environment . . . and for which,
therefore, neither an environmental assessment nor an environmental impact statement is
required" (40 CFR 1508.4). The categorical exclusions for MMS activities
were established through a public review and departmental approval process and are listed
in the departmental manual (516 DM 6, Appendix 10). These categorical exclusions may
be amended using the same review and approval process.
Some of the MMS categorical exclusions were developed based on experience in reviewing
actions for NEPA compliance in the past. For example, hundreds of environmental
assessments (EAs) were prepared for approval of certain types of oil and gas exploration
and development and production plans in the Central and Western Gulf of Mexico.
However, none of those EAs identified the need to prepare an environmental impact
statement (EIS). Therefore, we established a categorical exclusion for approval of
those plans. Other actions were excluded because it is obvious that they would have
no environmental impact. An example is the approval of applications for pricing
determinations under the Natural Gas Policy Act.
The Council on Environmental Quality (CEQ) developed the categorical exclusion process
to reduce the amount of unnecessary paperwork and delay associated with NEPA compliance.
If a certain type of MMS action, such as the issuance of regulations, would not
normally result in any environmental effects that are potentially significant, it is
unnecessary to spend time and effort to repeatedly document that fact. However, the
CEQ acknowledged that from time to time exceptions to a categorical exclusion may arise.
As a result, the CEQ requires all Agencies to develop procedures to determine
whether a normally excluded action may have a significant environmental effect. The
Categorical Exclusion Review (CER) determines whether a proposal that is categorically
excluded may meet any of the Department’s exception criteria (516 DM 2, Appendix 2).
