(a) Certain classes of environmental impacts normally require preparation of an EIS (40 CFR 1501.4). These include, but are not limited to:

(1) Potential for significant degradation of the environment.

(2) Potential for significant threat or hazard to public health or safety.

(3) Substantial environmental controversy concerning the significance or nature of the environmental impact of a proposed action.

(b) Certain other actions normally, but not always, require an EIS. These include, but are not limited to:

(1) Public land withdrawals of over 5,000 acres (Engle Act, 43 U.S.C. 155 through 158).

(2) Establishment of new air-to-ground weapons ranges.

(3) Site selection of new airfields.

(4) Site selection of major installations.

(5) Development of major new weapons systems (at decision points that involve demonstration, validation, production, deployment, and area or site selection for deployment).

(6) Establishing or expanding supersonic training areas over land below 30,000 feet MSL (mean sea level).

(7) Disposal and reuse of closing installations.