NEPA – Categorical Exclusion (CatX)
The term "NEPA" stands for National Environmental Policy Act and assures that federal agencies will consider the impact of an action on the human environment before decisions are made and the action is taken. NEPA establishes a specific documentation process requiring the agency to disclose the effect of actions affecting the environment.
In an effort to reduce paperwork and time delays, the Council of Environmental Quality (CEQ) provided an allowance (40 CFR 1500) for federal agencies to “categorically exclude” actions from public disclosure when it is determined that these actions do not individually or cumulatively have a significant effect on the human environment. There is no reference to “categorically exclude” in NEPA.
The key word is "significant". If a federal agency determines that the impacts of a proposal are significant, it must prepare the highest level of disclosure documentation referred to as an environmental impact statement (EIS) and make the decision-making process open to the public prior to final agency action.
In 1978, after extensive public review, CEQ amended federal regulations to clarify the intent of NEPA. The changes stressed that NEPA procedures must insure that environmental information is available to public officials and citizens before decisions are made and before actions are taken. And, the information must be of high quality and accurate scientific analysis. Most important, NEPA documents must concentrate on the issues that are truly significant to the action in question, rather than amassing needless detail.
NEPA's purpose is not to generate paperwork--even excellent paperwork--but to foster excellent action. The NEPA process is intended to help public officials make decisions that are based on understanding environmental consequences, and take actions that protect, restore, and enhance the environment.
Categorical Exclusions (CatEx) are actions that federal agencies can deem exempt from NEPA and therefore, do not require disclosure prior to final agency decisions. The term is applied to actions that do not individually or cumulatively have a significant effect on the environment: typically small, routine actions.
Exemption from NEPA does not imply exemption from other federal laws and regulations. The difference is how the agency chooses to document its compliance with all federal laws and the public's ability to access and review these documents. Categorical Exclusions are not applied to proposed actions that affect wetlands or threatened and endangered species.
While a review and assessment of projects is conducted prior to CatEx determination, there is no formal public comment period for projects that fall under categorical exclusions and they are not subject to appeal by the public
While NEPA requires that all agency actions be documented, it imposes no enforcement criteria to ensure compliance. Compliance is left to the courts. Legal action in 2005 (Earth Island Institute v. Ruthenbeck) restricted agency use of Categorical Exclusions.