In general, the environmental planning requirements of NEPA apply to all major Federal actions authorized, funded, or carried out by the Navy that may affect the environment. NEPA requires the identification and analysis of potential alternatives, analysis of potential impacts, and the identification of appropriate mitigation of impacts. There are three levels of NEPA documentation, including (in increasing order of complexity) a Categorical Exclusion (CATEX), an Environmental Assessment (EA), and an Environmental Impact Statement (EIS). CATEX documentation is generally prepared at the PWD level (for actions excluded from further NEPA analysis in accordance with OPNAVINST 509.1E), while EA and EIS documentation is generally prepared at the FEC level via contract. The appropriate level of NEPA documentation is dependent on the action being implemented. Appropriate documentation must be completed prior to initiating the action. Early involvement and coordination between the environmental program and the organization implementing the action is the key to effective and efficient environmental planning. Early coordination will assist with: avoidance or minimization of environmental impacts; identification of the necessary environmental consultations and permits; identification of mitigation measures and associated costs; timely completion of proper NEPA documentation to meet operational needs; and development of a realistic project schedule.
NEPA planning should be initiated at the earliest stage possible (e.g. project definition and initial siting evaluation) and NEPA documentation must be completed before initiation of the action (usually the construction award date) to avoid or reduce risks and costs associated with project design changes and potential litigation.