An environmental assessment (EA) is done to determine whether or not an action is a "major federal action significantly affecting the quality of the human environment." The Council on Environmental Quality (CEQ) regulations do not say much about the content of an EA, but they do contain a substantial definition of what it means to have a "significant" impact. This can be used to structure the EA analysis.
The EA is supposed to be "brief but thorough." It is not supposed to be "encylopedic," nor is it supposed to be a "mini-EIS" (environmental impact statement), though many are. It can be, and often is, the context in which other authorities, such as Section 106, are addressed.
The EA leads either to the decision to do an EIS or to a Finding of No Significant Impact (FONSI). The FONSI is published for public review and comment. Some courts have found that it is okay for a FONSI to include an agency's committment to mitigation measures that will, if implemented, bring the impacts of the project down below a significant level. Such FONSIs are referred to as "mitigated FONSIs."
About 50,000 EAs are done each year.
What should go into an EA?
The regulations are very unspecific about the required content of an EA, but they do say that the EA must explain the need for the proposed project, the alternatives considered, and the environmental impacts of each alternative. It must also identify agencies and persons consulted in preparing the EA.
The CEQ regulations, at Section 1508.27, define the word "significantly" as used when the Act refers to "major Federal action significantly affecting the quality of the human environment." Since it is such actions that require preparation of an EIS, the definition of "significantly" indicates how the significance of impacts should be measured in an EA. If the effects are not significant when measured against the definition, then a Finding of No Significant Impact (FONSI) can be issued and the project proceeds with no further NEPA review. If the definition is met, then an EIS is needed.
The definition is framed in terms of "context" and "intensity."
Context means the geographic, social, and environmental contexts within which the project may have effects. The regulations refer to:
- Society as a whole, defined as including all human society and the society of the nation
- The affected region
- Affected interests, such as those of a community, Indian tribe, or other group
- The immediate locality
The regulations also say that both short-term and long-term impacts must be considered – in other words, impacts must also be considered in the context of time.
It is important not to think of the various contexts as a hierarchy. An impact on society as a whole is not necessarily more important than an impact on a particular interest or locality.
"Intensity" is the severity of the potential impact considered in context. The regulations direct agencies to consider:
- Both beneficial and adverse impacts
- Impacts on human health and safety
- Impacts on an area's unique characteristics, such as historic or cultural resources, park lands, prime farmlands, wetlands, wild and scenic rivers, and ecologically critical areas
Note that impacts on "historic or cultural resources" are explicitly identified as attributes that must be addressed in order to measure the significance of a project's potential environmental effect. Hence such impacts must be considered in an EA.
Note also that it is "historic or cultural resources." The two terms are not synonymous.
The regulations go on to identify factors to consider in measuring the intensity of potential impacts: the possibility of controversy; the presence of uncertainty or unknown risks; cumulative effects; adverse effects on historic properties; scientific, cultural, or historical resources; endangered and threatened species; and potential violations of law or other requirement designed to protect the environment.
Controversy is generally understood to mean controversy about the environmental effects of a project – not mere unpopularity.
Cumulative effects refer to the role of a project's effects in contributing to a pattern of effects of multiple projects, programs, or trends.
Ideally, the definition of "significantly" at 40 CFR 1508.27 should provide an outline for an EA. Going through the outline – asking oneself, "Are we likely to affect this measure of intensity?" with respect to each measure, in each context – should bring the analyst to a logical conclusion about whether there will be a significant effect. Unfortunately, many agencies do not use the definition this way.
How are EAs reviewed?
The regulations are unspecific about internal and external review of an EA, so the amount and kind of review that takes place varies widely. Practically speaking, some kind of review is necessary in many cases, because whoever is preparing the EA obviously cannot know all the possible impacts. The preparer will have to ask people. This does not mean a formal review and comment process is necessary. Review may occur in the context of EA preparation, as part of consultation with knowledgeable or concerned parties, and with reference to other environmental laws like Section 106 of the National Historic Preservation Act (NHPA).
EAs and cultural resources
As noted, the definition at 40 CFR1508.27 mentions historic and cultural resources twice, in different ways. Clearly, impacts on both historic properties and other kinds of cultural resources are supposed to be considered in an EA. The EA is also an excellent, and commonly used, context for coordination with Section 106.
40 CFR 1508.14
40 CFR 1508.14 – the regulatory definition of the "human environment" – is an often misinterpreted section of the CEQ regulations. After defining the human environment to include the natural and physical environment and human relationships with that environment, it says that economic and social effects by themselves do not require preparation of an EIS. It goes on to say that when an EIS is prepared and economic or social effects are interrelated with effects on the natural or physical environments, then such effects must be considered.
Agencies have occasionally interpreted this to mean that they do not need to consider economic and social effects in an EA. This is a pretty exotic reading of the regulatory language. Section 1508.14 does not say that economic or social effects do not need to be considered in EAs. The point of 40 CFR 1508.14 is that if there are no other potential impacts requiring preparation of an EIS, economic and social impacts are not by themselves sufficient to constitute a "significant effect on the human environment."
Nor, of course, does 40 CFR 1508.14 mean that potential impacts on human culture and its resources are not sufficient by themselves to require preparation of an EIS, since it does not even mention such impacts.
The outcome of an EA
The EA results either in the conclusion that an EIS is necessary, or in a written FONSI. The FONSI, in theory, demonstrates that the impacts of the project do not rise to the level of significance, with reference to the significance measures listed at 40 CFR 1508.27. The FONSI:
- Includes either the whole EA or a summary (usually the latter)
- References any other pertinent environmental documents (e.g., an MOA)
- Says why it concludes that there is no significant impact
- Says if some factors are weighted more heavily than others
- In most jurisdictions, may include or refer to mitigation measures that the agency plans to implement in order to keep impacts below the level of significance (such a FONSI is called a "mitigated FONSI")
- Must be available to the public, but may or may not be put out for formal public review
Common problems with EAs
Since the CEQ regulations are vague about what should be in an EA, many if not most agencies and consultants simply adapt the much more detailed procedures for doing Environmental Impact Statements (EISs). This tends to result in long, complicated, costly documents that are, in essence, EISs with little or no public participation, and that are not particularly clear about why the agency thinks impacts will not be significant.
EAs and EISs serve fundamentally different purposes. An EA is to determine whether a specific threshold is crossed – the threshold of "significant" impact. An EIS simply has to reveal the impacts, not demonstrate that a threshold is or is not crossed. When an EA into a "mini-EIS," it becomes a document that often does not clearly show that there will or will not be a significant impact. Instead it merely discusses all the impacts (at best), and then asserts a conclusion whose relationship to the analysis is not always very clear.
In addition, of course, a "mini-EIS" may not be very "mini." It may be as long and complicated as a regular EIS; it is just usually prepared with little or no public participation.
Another problem is lack of "scoping": figuring out the scope of the analysis. Because the regulations talk of scoping only in the context of EISs, formal scoping is not always done with respect to an EA; instead the analysis done more or less by rote.
With respect to historic properties, a very common problem is "deferral," in which the agency acknowledges that it does not know much about what effects there may be on historic properties. It is assumed that whatever the effects are, Section 106 review, to be performed later, will take care of them, and therefore there is no significant impact.
With respect to other kinds of cultural resources, a common problem is that they are not considered at all. Historic properties (or even more narrowly, archeological sites) are sometimes the only things discussed in the "cultural resource" part of an EA. If social impacts are considered, they are often considered only in terms of easily quantifiable socioeconomic variables like population, employment, and use of public services. The result is that impacts on many classes of cultural resources simply are not identified or considered in deciding whether significant impacts may occur.