Environmental Document Review Level
DNA = Determination of National Environmental Policy Act Adequacy (agency administrative term) - If an existing EA or EIS, either prepared by the BLM or prepared by another agency with the BLM as a cooperating agency (40 CFR 1506.3(c)), fully covers the proposed action, a decision on the action may be made without further NEPA analysis. If an existing document does not fully cover the proposed action, a new NEPA document must be prepared.
CX = Categorical Exclusion - Categorical exclusions are categories of actions which Federal agencies have determined do not have a significant effect on the quality of the human environment (individually or cumulatively) and for which, therefore, neither an EA nor an EIS is generally required (40 CFR 1508.4). Departmental policy requires that categorically excluded actions be subjected to sufficient environmental review to determine whether they meet any of the exceptions to categorical exclusion (516 DM 2). Each time a specific categorical exclusions is used, the required review must be prepared.
EA = Environmental Assessment - An environmental assessment (EA) must be prepared for proposed actions that (1) are not exempt from NEPA, (2) have not been categorically excluded, (3) have not been covered in an existing Resource Management Plan EIS or other environmental analysis, or (4) do not normally or obviously require an EIS. An EA may be prepared for any action at any time to assist in planning and decision making.
EIS = Environmental Impact Statement - When a proposed action, including a proposed policy or legislative recommendation, is projected to have a significant impact on the quality of the human environment, an environmental impact statement (EIS) must be prepared. An EIS is intended to provide decision makers and the public with a complete and objective evaluation of significant environmental impacts, both beneficial and adverse, resulting from a proposed action and all reasonable alternatives. An EIS is a major vehicle for fulfilling the substantive environmental goals set forth in NEPA.