An Environmental Impact Statement (EIS) is required for any federal project that has significant impact on the environment. The EIS process is required under the National Environmental Policy Act (NEPA) and is used to evaluate the potential environmental impacts of a proposed federal action. The EIS process requires the lead agency to study the proposed action, consider alternatives to the proposed action, and assess the potential environmental impacts of each alternative. The EIS process also requires public input and consultation with other agencies before a final decision is made on the proposed action.