The BLM used the following methods and assumptions in the analysis of cumulative impacts:
Non-BLM oil and gas activities are based on the Reasonable Foreseeable Development Scenario for Oil and Gas (BLM 2009e).
For the purposes of estimating surface disturbance from reasonably foreseeable actions, for non-BLM activities (excluding oil and gas), the amount and density of activities is generally assumed to be the same for BLM and non-BLM actions, regardless of land ownership. Appendix T contains further information on these assumptions and the acreage of projected surface disturbance by alternative from non-BLM actions. Specific assumptions include:
The cumulative impacts from non-BLM mineral actions (excluding oil and gas) are based on the percent BLM vs. non BLM mineral estate in the Planning Area.
The cumulative impacts from other non-BLM development activities are based on the percent BLM- vs. non BLM-administered surface in the Planning Area.
The context and intensity of non-BLM activities are not anticipated to vary by alternative because these activities do not directly depend on management actions and allowable uses set forth in the RMP alternatives.
Cumulative impacts, such as soil erosion, spread of invasive species, and habitat fragmentation, are anticipated to increase with the amount of surface disturbance (Table 4–26).
Actions undertaken by private persons and entities are captured in public documents prepared by federal, state, and local government agencies.
For the estimation of air quality emissions, the context and intensity of non-BLM activities are not anticipated to vary by alternative. Additionally emissions from projects used to analyze cumulative impacts on air quality from non-BLM oil and gas activities were estimated using data on existing and projected oil and gas wells in the Planning Area from the Reasonable Foreseeable Development Scenario for Oil and Gas (BLM 2009e) and a similar methodology to that described in Appendix U. The BLM estimates that on private and fee (i.e., non-federal) land in the Planning Area, there are 201 existing conventional gas wells and 1,342 existing oil wells. At the end of the planning cycle, the BLM projects the drilling of 511 new oil and gas wells on non-federal mineral estate in the Planning Area (BLM 2009e). The BLM used this information to estimate emissions from oil and gas wells for the 2015 and 2024 emission projection years. For natural gas emissions, cubic feet of natural gas produced during the planning cycle on non-federal mineral estate was estimated using expected natural gas production in 2015 and 2024 from projected federal wells in the Planning Area.
For cumulative impacts associated with other activities (i.e., non-oil and gas), the amount and density of activities is assumed to be the same for both BLM and non-BLM actions; therefore, the analysis of non-BLM salable and locatable mineral activities is based on the proportional mineral estate ownership in the Planning Area (74 percent federal and 26 percent non-federal). The calculation of cumulative impacts for air quality from non-mineral, non-BLM activities is based on the proportion of surface ownership in the Planning Area (56 percent BLM-administered and 44 percent non BLM-administered). Alternative A continues management under the existing plans and is, therefore, assumed to provide the best baseline from which to estimate future emissions for non-BLM actions. Since the context and intensity of non-BLM actions are not anticipated to vary by alternative, the emissions from non-BLM actions estimated under Alternative A were carried forward under alternatives B, C, and D.
The majority of projects identified in Table 4–27 are programmatic and/or strategic in nature; therefore, the exact intensity or location of anticipated impacts cannot be quantified. For more quantitative analysis, the BLM projected the anticipated surface disturbance and air emissions from non-BLM reasonably foreseeable actions for the entire Planning Area (Appendix T). The estimates of reasonably foreseeable actions in Appendix T are based on historic and trend information, as well as the proportion of public to non-public land in the Planning Area. In addition to estimating reasonably foreseeable actions for BLM and non-BLM actions, Appendix T also projects short-term and long-term surface disturbance. Long-term surface disturbance describes the disturbed area remaining following reclamation. Table 4–26 summarizes projected surface disturbance for BLM and non-BLM reasonably foreseeable actions identified in Appendix T.
Where appropriate, analyses of historic and current trends are used to assess cumulative impacts. For example, the subdividing of private land in rural areas is expected to continue in the future.
Table 4.26. Cumulative Surface Disturbance in Acres from BLM and Non-BLM Reasonably Foreseeable Actions
| Action | Alternative A | Alternative B | Alternative C | Alternative D |
| Total Acres Short-Term Disturbance from BLM Actions | 136,415 | 73,919 | 245,783 | 140,508 |
| Total Acres Reclaimed from BLM Actions | 120,705 | 63,037 | 204,238 | 122,065 |
| Total Acres Long-Term Disturbance from BLM Actions | 15,710 | 10,882 | 41,545 | 18,443 |
| Total Acres Short-Term Disturbance from Non-BLM Actions | 24,129 | 26,048 | 24,154 | 24,129 |
| Total Acres Reclaimed from Non-BLM Actions | 14,494 | 16,494 | 14,494 | 14,494 |
| Total Acres Long-Term Disturbance from Non-BLM Actions | 9,635 | 9,555 | 9,660 | 9,636 |
| Cumulative Long-Term Acres from Disturbance | 25,346 | 20,436 | 51,206 | 28,079 |
Source: Appendix T
Most projects identified in Table 4-27 are ongoing and provide a management framework for site-specific actions implemented during the life of the various projects. Though they are considered in this cumulative impacts analysis, refer to Chapter 3 – Affected Environment, for a detailed description of site-specific past and present (i.e., ongoing) actions. Only those reasonably foreseeable future actions resulting from the 40 projects identified in Table 4-27 and Appendix T are considered in this cumulative impacts analysis.
Table 4.27. Summary of Reasonably Foreseeable Future Actions
| Resource Plans | Physical Resources | Air Quality | Geology | Soil | Water | Cave and Karst Resources | Mineral Resources | Fire and Fuels Management | Biological Resources | Heritage and Visual Resources | Cultural Resources | Paleontological Resources | Visual Resources | Land Resources | Lands and Realty | Renewable Energy | Rights-of-Way and Corridors | Travel and Transportation Management | Recreation | Lands with Wilderness Characteristics | Livestock Grazing Management | Special Designations | ACECs | Scenic or Back Country Byways | National Historic Trails | Wild and Scenic Rivers | Wilderness Study Areas | Socioeconomic Resources | Social Conditions | Economic Conditions | Health and Safety | Environmental Justice | Tribal Treaty Rights |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| BLM RESOURCE MANAGEMENTS PLANS AND OTHER FEDERAL PLANS AND ANALYSES | |||||||||||||||||||||||||||||||||
| Approved Resource Management Plan for Public Lands Administered by the Bureau of Land Management Buffalo Field Office Final Environmental Impact Statement (BLM 2001a) | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | ||||||||||||
| Final Resource Management Plan/Environmental Impact Statement for the Lander Resource Area (BLM 1986b). | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | ||||||||||||
| Final Programmatic Environmental Impact Statement on Wind Energy Development on BLM-Administered Lands in the Western United States (BLM 2005d) | X | X | |||||||||||||||||||||||||||||||
| Final Environmental Impact Statement Resource and Management Plan Billings Resource Area, 1983 | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | ||||||||||||
| DOE and BLM. 2008. Programmatic Environmental Impact Statement, Designation of Energy Corridors on Federal Land in the 11 Western States (DOE/EIS-0386) | X | X | |||||||||||||||||||||||||||||||
| BLM and USFS (U.S. Forest Service). 2008. Final Programmatic Environmental Impact Statement (EIS) for Geothermal Leasing in the Western United States. | X | ||||||||||||||||||||||||||||||||
| COUNTY PLANS | |||||||||||||||||||||||||||||||||
| Big Horn County Land Use Plan | X | X | X | X | X | X | X | X | X | X | X | X | |||||||||||||||||||||
| Hot Springs County Land Use Plan | X | X | X | X | X | X | X | X | X | X | X | X | X | ||||||||||||||||||||
| Park County Land Use Plan | X | X | X | X | X | X | X | X | |||||||||||||||||||||||||
| Washakie County Land Use Plan | X | X | X | X | X | X | X | X | X | X | X | ||||||||||||||||||||||
| CONSERVATION DISTRICTS | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| South Big Horn CD Long Range Plan | X | X | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Hot Springs County CD Plan | X | X | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Meeteetse CD Land Use Management and Resource Conservation Plan 2010 | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | X | |||||||||||||||||||||||||||||||||||||||||||||||||||
| Cody CD Long Range Plan | X | X | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Shoshone CD Plan | X | X | X | X | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Powell Clarks Fork Conservation District Plan | X | X | X | X | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Washakie County CD Plan | X | X | X | X | X | X | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| WATERSHED PLANS | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Big Horn River Watershed Plan | X | X | X | X | X | X | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| South Big Horn County, Wyoming Watershed Plan | X | X | X | X | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Greybull Watershed Draft Plan | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Shoshone Water Management Plan 2006 | X | X | X | X | X | X | X | X | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Shoshone River Watershed Plan Draft 2008 | X | X | X | X | X | X | X | X | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bitter Creek Watershed Plan | X | X | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| STATE AGENCY PLANS | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Wyoming Dept of Agriculture Strategic Plan 2005 | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Wyoming Game and Fish Strategic Habitat Plan | X | X | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Wyoming Game and Fish Greater Sage-Grouse Conservation Plan | X | X | X | X | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Wyoming Game and Fish Final Wyoming Gray Wolf Management Plan 2007 | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Wyoming State Water Plan Wind/Bighorn River Basin 2003 | X | X | X | X | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Wyoming Statewide Comprehensive Outdoor Recreation Plan (2003) | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Wyoming Statewide Trails Plan 2004 | X | X | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Wyoming SHPO Comprehensive Statewide Historic Preservation Plan 2007-2015 | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| FEDERAL AGENCY PLANS | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Shoshone National Forest Plan | X | X | X | X | X | X | X | X | X | X | X | X | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bighorn National Forest Plan | X | X | X | X | X | X | X | X | X | X | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| United States Fish and Wildlife Service Wyoming Plan | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| United States EPA Region 8 Wyoming State Implementation Plans | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| FIRE MANAGEMENT PLANS | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Yellowstone National Park Fire Management Plan | X | X | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Big Horn County Mountain Community Wildfire Protection Plan | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Park County Community Wildlife Protection Plan | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Washakie County Community Wildfire Protection Plan | X | X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| National Fire Plan | X | X | X | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| ACECs = Areas of Critical Environmental Concern BLM Bureau of Land Management CD = Conservation District Dept = Department EPA = Environmental Protection Agency SHPO = State Historic Preservation Office | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||