Don’t Overlook This Crucial Aspect of NEPA Analysis: Understanding Cumulative Impacts and the Latest Definition

In May 2022, the definition of cumulative impacts was added back into the National Environmental Policy Act (NEPA) regulations after being removed during the Trump administration. The definition was removed from 40 CFR 1508.7 and added back in as 40 CFR 1508.1(g)(3). For those who missed it, you can check out our May 2022 blog post on the NEPA regulation changes. While some federal agencies continued to apply a cumulative impacts analysis even without the definition, its removal made it optional and inconsistent among agencies. However, with the new definition back in place, it is now a requirement for all federal agencies to consider the effects of their proposed actions in combination with the effects of other past, present, and reasonably foreseeable actions. While prior guidance by the Council on Environmental Quality (CEQ) and the Environmental Protection Agency (EPA) existed before the definition of cumulative impacts was removed, we have noticed a lack of new guidance since its reinstatement. In this article, we will explore the differences between the old and new definitions of cumulative impacts, as well as the guidance provided by CEQ on conducting cumulative impacts analysis and whether it appears to still apply.

1. The Definition of Cumulative Effects:

Cumulative effects refer to the environmental consequences that arise when the effects of one action, in combination with the effects of past, present, and reasonably foreseeable future actions (regardless of the responsible entity), add up over time. These impacts can stem from seemingly insignificant impacts that, when taken together, have a significant overall impact. They are the sum total of all effects on a specific resource that have happened, are happening, and are expected to happen due to any action or influence.

• Old Definition: The old definition of cumulative impacts was defined in 40 CFR section 1508.7 as the “impact on the environment which results from the incremental impact of the action when added to other past, present, and reasonably foreseeable future actions regardless of what agency (federal or non-federal) or person undertakes such other actions.”
• New Definition: The new definition of cumulative effects is defined in 40 CFR section 1508.1(g)(3) as “effects on the environment that result from the incremental effects of the action when added to the effects of other past, present, and reasonably foreseeable actions regardless of what agency (federal or non-federal) or person undertakes such other actions.”
• The main difference between the two definitions is the wording used to describe the impact and effects on the environment.
• The new definition uses the term “effects” instead of “impact.” The terms effect and impact are used synonymously in the CEQ regulations. However, the new definition specifies that cumulative effects result from adding the effects of one action to the effects of other actions. The old definition did not specify that the impacts of one action were to be analyzed with the impacts of other actions.

2. Cumulative Impacts Guidance – Where Is It?

CEQ guidance on cumulative impacts analysis can be found on the CEQ’s website, which is part of the White House Council on Environmental Quality. The CEQ has issued several guidance documents related to cumulative impacts analysis over the years, including:

• “Considering Cumulative Impacts Under NEPA” (1997)
• “Guidance for NEPA Mitigation and Monitoring” (2011)
• “Final Guidance on Improving the Process for Preparing Efficient and Timely Environmental Reviews Under the National Environmental Policy Act” (2020)

However, it’s worth noting that the CEQ website has undergone changes in recent years, and some guidance documents may no longer be easily accessible. As a result, some organizations and agencies have posted copies of CEQ guidance on their own websites, to ensure that the information remains available to the public. For example, the Department of Energy’s NEPA website includes a number of CEQ guidance documents related to NEPA analysis, including the 1997 guidance on cumulative impacts.

3. Cumulative Impacts Guidance – What Does It Say?

• CEQ 2005 Guidance:
  • The Council on Environmental Quality (CEQ) 2005 Guidance on the Consideration of Past Actions in Cumulative Effects Analysis provides guidance on how to consider past actions in cumulative effects analysis. The guidance recommends considering past actions when evaluating the incremental effects of a proposed action and considering the potential for the proposed action to contribute to an ongoing or future cumulative impact.
• EPA 1999 Consideration:
  • The EPA 1999 Consideration of Cumulative Impacts in EPA Review of NEPA Documents provides guidance on how to consider cumulative impacts in the NEPA process. The guidance recommends considering the potential for cumulative impacts to occur, identifying the scope of the analysis, and considering alternatives that would avoid or minimize cumulative impacts.
• CEQ Guidance of 1997:
  • The CEQ guidance of 1997, “Considering Cumulative Impacts Under NEPA,” provides guidance on how to consider cumulative impacts in NEPA analysis. The guidance recommends evaluating the potential for cumulative impacts, considering the significance of the impacts, and identifying alternatives that would avoid or minimize cumulative impacts.

4. Cumulative Impacts Guidance – Does It Still Apply?

• While the new definition of cumulative impacts has been added back into NEPA regulations, the prior guidance provided by CEQ and EPA is still applicable and provides helpful recommendations for agencies conducting NEPA analysis.

5. Why Completing a Cumulative Impacts Analysis Is Difficult?

• Cumulative impacts analysis is difficult because it requires agencies to consider the effects of their proposed action in combination with the effects of other past, present, and reasonably foreseeable actions.
• It can be challenging to identify and quantify the individual effects of each action, as well as the combined effects of multiple actions over time.
• Additionally, agencies must consider the significance of cumulative impacts and identify alternatives that would avoid or minimize those impacts, which can be complex and time-consuming.

Understanding cumulative impacts is an important part of NEPA analysis, and agencies must consider the potential for cumulative impacts to occur and identify alternatives that would avoid or minimize those impacts. With the new definition of cumulative impacts added back into NEPA regulations, it is crucial to be aware of prior guidance provided by CEQ and EPA to ensure a thorough analysis of potential cumulative impacts.

At Scout, we make it a priority to stay up to date on changes that make a difference in environmental policy. We’re here to make sure your organization is compliant with the most current environmental guidance and best management practices. Contact us at hello@scoutenv.com