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Evaluating Significance - Full EAF (Part 3)

Full Environmental Assessment Form (FEAF) Workbook

The term 'significant' is somewhat subjective. That is because the significance of an impact is dependent on the magnitude, duration, and likelihood of that impact occurring. It is also dependent on the scale and context of the project. Context refers to the unique characteristics of the natural and man-made environment in any given location. Significance is very much tied to the context of the site and the community. Similar projects may receive different decisions on significance because of differences in the context. Each impact therefore, must be judged and weighed by these different characteristics.

What could be a significant impact?

The reviewing agency makes the decision about whether a potential impact is significant or not. Many variables go into a determination of significance. The significance of an impact is based on the specific environmental setting where the activity is proposed, on the type of resource being impacted, and on the values, history, and preferences of the community.

The information that goes into, and the reasoning behind a determination of significance is presented in Part 3 in a logical, comprehensive, and understandable manner. A legally sufficient determination of significance implies that a lead agency has in its possession, and can demonstrate that it has considered at least the following:

  • The entire action, not just one part of it (see Segmentation);
  • The information provided from the environmental assessment form (EAF);
  • Any other information provided by the applicant, including the underlying application;
  • The criteria for determining significance found in 617.7(c) ; and
  • Any input from involved and interested agencies, interested organizations or other groups of people and the general public.

The specific criteria for determining the significance of an action comes in part from the criteria listed in 617.7(c). These criteria assist the reviewing agency by focusing attention on a wide range of important environmental considerations. But this list is illustrative, not exhaustive. Agencies may develop additional criteria to those listed in 617.7(c), especially if past experience has indicated the importance of particular considerations with respect to actions frequently encountered by an agency. Such additional criteria should be developed and adopted in accordance with rules governing individual agency implementation of SEQR, see 617.14(e).

The information provided in this section of the workbook offers the reviewing agency tools to help pull all the known information together, organize decisions, and make that determination of significance.

For each potential impact, there are many combinations of magnitude, duration, and likelihood that can occur. There is no universally accepted measure of significance. None of the criteria (magnitude, duration, likelihood, scale, and context) should be considered more important than any other. Instead, they should be examined in an equal manner to help frame the rationale for making a determination of significance and for communicating why you made that determination.

Whether a potentially adverse impact is significant or not is ultimately determined or tempered by the specifics related to the scale of the proposed project and context within your community. Remember that the determination of significance needs to be based as well on the magnitude, duration, and likelihood of an impact occurring. These criteria cannot be inserted into a formula that will automatically produce a finding of significance or insignificance. These criteria simply aid the reviewing agency in making a judgment on a case-by-case basis.

The following steps and information will help you determine the environmental significance of the moderate top large impacts identified in Part 2.

Making and Organizing Your Decisions

Each moderate to large impact needs to be discussed and evaluated for its magnitude, duration, importance and likelihood. The reviewing agency will need to take each moderate to large Part 2 impact, make decisions on these factors, and then take a comprehensive view of them all together to determine if the impact will be significant.

Because there are many variables that will influence your determination of the significance of an impact, it may be useful to organize your decisions for each impact discussed. Using a chart or checklist can be a helpful tool. The chart below is a tool to help you organize, think about, and help make your decisions on magnitude, duration, and likelihood for each impact. The chart illustrates the options to be considered. If you use a tool similar to the following chart, you can circle or highlight one choice in each column for each Part 2 impact to be evaluated.

Magnitude of Impact Duration of Impact Likelihood of Impact Importance of Impact
Moderate (localized)

Large (Severe)



Unlikely to occur

Possibly will occur

Probably will occur
Not Important

Fairly Important

Very Important

An Example Using the Chart

The following example illustrates an action that, according to Part 2, the reviewing agency determined could have moderate to large impacts. This example is for a project proposed to be built in an area having significant archaeological resources. The Planning Board evaluated the information available and determined that the potential impacts on the archaeological resources are confined to the parcel itself, are irreversible because the resources could potentially be destroyed, that the type of resources are very important because of the reliance on those archeological resources as a significant part of the community's identity, and that the impacts will probably occur because the site plan shows disturbances to the area where the resources exist. The chart below summarizes the thought process that went into the Planning Board's evaluation of this particular impact:

Magnitude of Impact Duration of Impact Likelihood of Impact Importance of Impact
Question 8:
Impact on historic, archaeological, architectural, or aesthetic resources
Moderate - because a significant portion of the parcel will be impacted




Irreversible - because the resources could be destroyed during construction or permanently made inaccessible
Unlikely to occur

Possibly will occur

Probably will occur - because the site plan shows grading, soil removal and construction over the site where the resources are located
Not Important

Fairly Important

Very Important

Once the reviewing agency has identified the magnitude, duration, importance and likelihood of all adverse significant impacts, it's time to start writing the Statement of Significance.

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