GOA Admin

The National Environmental Policy Act (NEPA) of 1969 requires federal agencies to examine the potential environmental effects of their actions to allow for more informed decision-making. An Environmental Impact Statement is a detailed public document that provides an assessment of the potential effects that a major federal action might have on the environment. The United States Department of the Navy’s analysis under NEPA extends through the United States’ territorial sea (from shore to 12 nautical miles). An Overseas Environmental Impact Statement is prepared to comply with Executive Order 12114, Environmental Effects Abroad of Major Federal Actions, of 1979, which requires federal agencies to consider the potential effects of their actions on the physical environment outside the United States, its territories, and possessions.

A supplement to an environmental impact analysis is prepared when there are new circumstances, information, or substantial changes to the action or environmental analysis, relevant to environmental concerns.

NEPA requires that an environmental impact analysis of the resources and areas potentially affected by the Proposed Action be completed by federal agencies. However, while all resources must be considered, those resources that will not be affected by the Proposed Action, or impacts that were analyzed in a broader environmental impact statement (i.e., tiering), need not be analyzed in detail or may be incorporated by reference.

As stated in 43 Federal Register 56003, §1508.28, "Tiering" refers to the coverage of general matters in broader environmental impact statements, with subsequent narrower statements or environmental analyses incorporating by reference the general discussions of the previous environmental impact statement and concentrating solely on the issues specific to the statement subsequently prepared.