The CEQ defines cumulative effects 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 (40 CFR 1508.7).
The Bighorn Basin RMP Revision Project addresses the three components of this definition of cumulative effects as follows:
Incremental impacts of the RMP revision. The incremental impacts of the action (i.e., the revision of the three RMPs), are described for each resource in the preceding sections of this chapter as direct, indirect, short-term, and long-term impacts.
Impacts from all past and present actions. The impacts from past and present actions are captured in the baseline conditions presented in Chapter 3 – Affected Environment. As discussed in that chapter, the description of the current affected environment reflects past and present actions.
Reasonably foreseeable future actions. Other reasonably foreseeable future actions are identified in Appendix T and the total projected surface disturbance from these actions appears in the following section.
The analysis of cumulative impacts serves to place the projected incremental impacts from the proposed alternatives in the context of past, present, and future impacts. Combining the projected impacts of proposed alternatives with past, present, and future impacts necessarily involves projections and constrains analyses. Public documents prepared by federal, state, and local government agencies are the primary sources of information regarding past, present, and future actions. Speculative or uncommitted projects are not included in the projections. Analyses are limited, primarily due to incomplete documentation of all past and present impacts on private and public lands; challenges in predicting potential impacts for reasonably foreseeable future actions; the programmatic and strategic nature of proposed alternatives; the unknown nature and pace of resource uses and technological changes that could occur; and changing circumstances related to agency priorities, policies, and the economy. These limitations are addressed through the methods and assumptions described in the following section.
This section identifies 40 reasonably foreseeable future projects and actions in or adjacent to the Planning Area. The breakdown of the 40 projects by agency includes three BLM RMPs, one BLM Programmatic Wind Energy EIS, one BLM Programmatic Energy Distribution Corridor EIS, one BLM Programmatic Geothermal Leasing EIS, four County Land Use Plans, seven Conservation District Plans, six Watershed Plans, one Wyoming Department of Agriculture Strategic Plan, three Wyoming Game and Fish Department Plans, one Wyoming State Water Plan for the Wind/Bighorn River Basin, two Wyoming Statewide Outdoor Recreation and Trail Plans, one Wyoming State Historic Preservation Office Statewide Plan, one USFWS Plan, two NPS General Management Plans, one Wyoming State Plan, three County FMPs, one NPS FMP for Yellowstone National Park, and one National Fire Plan. Many of these plans have already been adopted, in which case the reasonably foreseeable actions stem from the ongoing implementation of the plans.