NEPA Categories23 Environmental
Impact Categories

There are 23 environmental impact categories that will be evaluated as part of the Environmental Assessment. The information provided here is taken from the FAA’s Environmental Desk Reference for Airport Actions (October 2007).  The complete FAA document and individual chapters are available online.

Air Quality:  Detailed analysis is needed for a project that, due to its size, scope, or location has the potential to affect the attainment and maintenance of established air quality standards.  Those standards are known as “National Ambient Air Quality Standards.

Biotic Resources:  The term “biotic resources” means various types of flora (plants) and fauna (fish, birds, reptiles, amphibians, marine mammals, coral reefs, etc.) in a particular area. The term also means rivers, lakes, wetlands, forests, upland communities, and other habitat types supporting flora and aquatic and avian fauna.  A NEPA document’s Biotic Resources text must address the effects on biotic resources due to a proposed action and its reasonable alternatives. The text must also address action-related effects and consequences on the affected area’s state-listed rare or unique species or their habitats.

Coastal Barriers:  Barrier islands protect fish, wildlife, human life, and property along coasts and shorelines.  As needed, the airport sponsor or responsible FAA official should review Coastal Barrier Resource System (CBRS) maps to determine if an action under consideration would occur within the CBRS.

Coastal Zone Management:  Under most circumstances, all airport actions that would occur in or that would affect a coastal zone of a state having an approved state coastal zone management program must comply with that program to meet the requirements of the Coastal Zone Management Act of 1972, as amended (CZMA).

Compatible Land Use:  The compatibility of existing and planned land uses in the vicinity of an airport is usually associated with the extent of the airport’s noise impacts. If the noise analysis concludes that there is no significant noise impact, a similar conclusion usually may be made about compatible land uses.  If the action would cause noise impacts that affect land uses such as social or induced socioeconomic effects, those effects are analyzed in the context of the affected resource(s). Besides the effects of noise on land use compatibility, the FAA should also assess the compatibility of land uses in the vicinity of an airport to ensure those uses do not adversely affect safe aircraft operations. Examples of such land uses that may adversely affect those operations include municipal landfills and wetland mitigation that attract wildlife species hazardous to aviation.

Construction:  The construction impacts text describes the general types and natures of construction-related impacts and the measures proposed to minimize potential, construction-induced adverse effects.  Airport construction may cause various environmental effects primarily due to dust, aircraft and heavy equipment emissions, storm water runoff containing sediment and/or spilled or leaking petroleum products and noise. In most cases, these effects are subject to Federal, State, or local ordinances or regulations.

Section 4(f):  Section 4(f) of the Department of Transportation Act of 1966 states that, subject to exceptions for de minimis impacts, the Secretary of Transportation may approve a transportation program or project requiring the use of publicly-owned land of a park, recreational area, or wildlife and waterfowl refuge of national, state, or local significance or land of a historic site of national, state, or local significance as determined by the official having jurisdiction over those resources only if: (1) there is no prudent and feasible alternative that would avoid using those resources, and (2) the program or project includes all possible planning to minimize harm resulting from the use.

Federally-listed Endangered and Threatened Species:  To satisfy the Endangered Species Act of 1973, the Federal Aviation Administration (FAA) must determine if a proposed action under its purview would affect a Federally-listed endangered or threatened species or habitat critical to that species (critical habitat).

Energy Supplies, Natural Resources, and Sustainable Design: Airport development actions have the potential to change energy requirements or use consumable natural resources. To comply with the Council on Environmental Quality (CEQ), Federal Aviation Administration (FAA) environmental documents must evaluate potential impacts on supplies of energy and natural resources needed to build and maintain airports. FAA policy supports developments displaying environmental sustainability.

Environmental Justice:  Environmental justice analysis considers the potential of Federal actions to cause disproportionate and adverse effects on low-income or minority populations. Environmental justice ensures no low-income or minority population bears a disproportionate burden of effects resulting from Federal actions.

Farmlands:  Important farmlands include all pasturelands, croplands, and forests (even if zoned for development) considered to be prime, unique, or important farmland (designated statewide or locally).  Any airport development action funded under the Airport Improvement Program (AIP) or subject to FAA approval that would permanently convert an existing designated important farmland to a non-agricultural use is subject to coordination with the Farmland Protection Policy Act (FPPA).

Floodplains:  All airport development actions must avoid the floodplain, if a practicable alternative exists. If no practicable alternative exists, actions in a floodplain must be designed to minimize adverse impact to the floodplain’s natural and beneficial values. The design must also minimize the potential risks for flood-related property loss and impacts on human safety, health, and welfare.

Hazardous Materials: Federal, State, and local laws regulate hazardous materials use, storage, transport, or disposal. These laws may extend to past and future landowners of properties containing these materials. In addition, disrupting sites containing hazardous materials or contaminates may cause significant impacts to soil, surface water, groundwater, air quality and the organisms using these resources. Therefore, airport sponsors purchasing or developing land for airport purposes may encounter hazardous materials contamination. The environmental document should disclose and analyze information about hazardous materials.

Historic and Archeological:  Section 106 of the NHPA, as implemented through 36 CFR Part 800, is intended to require Federal agencies to consider the effects of their undertakings on historic properties. A historic property is, “any prehistoric or historic district, site, building, structure, or object included in, or eligible for inclusion in the National Register of Historic Places (NRHP) maintained by the Secretary of the Interior” (36 CFR Section 800.16(l)). Properties or sites having traditional religious or cultural importance to Native American Tribes and Hawaiian organizations may qualify.

Induced Socioeconomic:  The FAA must evaluate a proposed airport project to determine the project’s potential to cause induced or secondary socioeconomic impacts on surrounding communities. When the FAA determines a potential for such impacts exists, the environmental document should describe how the proposed project would affect communities by addressing the following factors, as needed: (1) shifts in patterns of population movement and growth; (2) public service demands; (3) changes in business and economic activities; or (4) other factors identified by the public.

Light Emissions and Visual Effects:  Airport-related lighting facilities and activities could visually affect surrounding residents and other nearby light-sensitive areas such as homes, parks or recreational areas. There are no Federal statutory or regulatory requirements for adverse effects. However, if there is a potential for airport lighting to disturb these sensitive land uses, the responsible FAA official should ensure the environmental document examines those effects. If potential light emissions or visual effects exist, the official should evaluate measures to lessen those as well. This helps promote a “good-neighbor” policy while protecting the resource.

Noise:  FAA’s noise analysis primarily focuses on how proposed airport actions would change the cumulative noise exposure of individuals to aircraft noise in areas surrounding the airport. Besides using noise levels to determine compatible land use, airport noise may be a concern when determining potential effects on other environmental resources including, but are not limited to, Section 4(f)-protected resources and historic and cultural sites. The Day Night Average Sound Level (DNL) is the standard Federal metric for determining cumulative exposure of individuals to noise. In 1981, FAA formally adopted DNL as its primary metric to evaluate cumulative noise effects on people due to aviation activities. The FAA requires the use of the Integrated Noise Model (INM) for airport development actions requiring a detailed noise analysis. INM is an average-value-model designed to estimate long-term average effects using average annual input conditions.

Social Impacts:  FAA must evaluate proposed airport development actions to determine if they would cause social impacts. This evaluation should include effects on health and safety risks to children, and socioeconomic impacts. Those impacts include moving homes or businesses; dividing or disrupting established communities; changing surface transportation patterns; disrupting orderly, planned development; or creating a notable change in employment.

Solid Waste:  Construction, renovation, or demolition of most airside projects produces debris (e.g., dirt, concrete, asphalt) that must be properly disposed. In addition, new or renovated terminal, cargo, or maintenance facilities may involve construction, renovation, or demolition that produces other types of solid waste (bricks, steel, wood, gypsum, glass). Therefore, airport sponsors should follow Federal, state, or local regulations that address solid waste. Doing so reduces the environmental effects of airport-related construction or operation.

Water Quality:  Many of the nation’s airports are located near waterways. This is because years ago when many airports were built, the cheapest, flattest, and most desirable lands suitable for airports were located near waterways. As a consequence, today’s airport activities may cause water quality impacts due to their proximity to waterways. In particular, construction activities or seasonal airport anti-icing/deicing activities are major concerns. Construction often causes sediment-laden runoff to enter waterways. Biological and chemical breakdown of deicing chemicals in airport runoff can cause severe dissolved oxygen demands on receiving waters. Operations or maintenance are other activities that may affect water quality. Airport-related water quality impacts can occur from both point and non-point sources at airports. If not properly controlled, the resultant water quality impacts may adversely affect animal, plant, or human populations. Therefore, FAA must evaluate project-related discharges, especially those having the potential to affect navigable waterways, municipal drinking water supplies, important sole-source aquifers, or protected groundwater supplies.

Wetlands:  Both Jurisdictional and Non-jurisdictional wetlands are natural resources that the FAA must assess under NEPA.  Jurisdictional wetlands are those wetlands connected or adjacent to navigable waters of the U.S. as defined by Section 404 of the Clean Water Act (CWA).  Federal agencies must avoid wetlands when a practicable alternative avoiding a wetland exists. A practicable alternative is an alternative that is possible (i.e., feasible), after considering the alternative’s: (1) safety aspects; (2) ability to meet the action’s transportation objectives; and (3) ability to meet accepted design, engineering, environmental, economic, or any other applicable factors.

Wild and Scenic Rivers:  The environmental analysis of a proposed airport action that involves a water resource action (see section 1.d of this chapter) that may affect a Wild and Scenic Rivers System (WSRS) or a river listed on the National Rivers Inventory (NRI) river must include discussions of potential impacts to the river.

Cumulative Impacts:  Cumulative impacts are impacts the proposed action would have on a particular resource when added to impacts on that resource due to past, present, and reasonably foreseeable actions within a defined time and geographical area. Note that this range of actions includes actions FAA itself undertakes as well as those for which any other public or private entity is responsible.