Levels of NEPA Analysis

NEPA recognizes that some projects are much more complex than others. Therefore, NEPA allows for four different levels of analysis:

  1. Categorical Exclusion (CX or CE) often referred to as a “CatEx” If the Lead Agency determines that the proposed action does not individually (or cumulatively) have significant effects on the human environment, then the agency can issue a CX and no further study is needed – the project is excluded from the NEPA process.
  2. Documentation of NEPA Adequacy (DNA or SIR) If the Lead Agency determines that the proposed action has been adequately studied previously, then the agency can grant a DNA to the developer and no further study is required.  The Forest Service calls this designation a “Supplemental Information Report” or SIR as discussed in FS 1909.15 Section 18.1 of the USFS handbook at http://www.fs.fed.us/cgi-bin/Directives/get_dirs/fsh?1909Computer screen with graph
  3. Environmental Assessment (EA) An EA is a concise written analysis of a proposed action’s possible effects to determine whether or not they are potentially significant enough to warrant further study, that is, an Environmental Impact Statement (EIS).  Sometimes the developer proposing the action will prepare an EA but then the Lead Agency must review this EA to determine if it meets NEPA requirements for a Finding of No Significant Impact (FONSI). If this decision is reached then the agency issues a Decision Notice explaining the reasoning behind this action. If the lead agency decides that there is potential for significant impact(s), then they will require that an EIS be prepared on the project.
  4. Environmental Impact Statement (EIS) An EIS is an environmental analysis of not only the developer’s proposed action but also any reasonable alternative actions that would cause fewer environmental impacts. The EIS process is as important as is the final environmental documentation and Record of Decision (ROD).  Often the Lead Agency will hire a third party contractor to prepare the EIS following the Lead Agency’s specifications. Some agencies use the final document as reference and guidance by carefully considering the final EIS before their permit conditions are finalized; other agencies, like the US Forest Service use the ROD as the final decision-making document.
The ability of the public to participate in the EIS study process in a meaningful way is critical to the NEPA process.