The National Environmental Policy Act (NEPA) requires that U.S. federal agencies or anyone receiving federal funding prepare detailed analyses of any of their actions that significantly affect the quality of the environment. Almost all developments, such as roads, houses and airports, have an impact on the environment.
Environmental Impact Statements (EIS) are documents that help the government and the general public understand the effects of developments on the environment and to decide whether developments should go ahead. NEPA does not prohibit the federal government or its licensees/permittees from harming the environment, but requires that the prospective impacts be understood and disclosed in advance and may mandate various modifications and safeguards designed to protect the environment.
In recent years, EISs have looked increasingly at biodiversity. Most EIS documents will include a description of major habitats and a list of the plant and animal species present. They also pay particular attention to the presence of threatened species. Where the effects are considered significantly harmful to threatened species, an additional document, the Species Impact Statement (SIS), may also be prepared.
