Under all alternatives, management that results in areas being open, open with constraints, or administratively unavailable would respectively allow, limit, or prohibit exploration and development in certain areas. This management would result in direct impacts to oil and gas development. Impacts would be similar across alternatives because the definition of areas open subject to the standard lease form, open with moderate constraints, open with major constraints, and administratively unavailable are the same for all alternatives (see Glossary ). The severity of these impacts would vary by alternative based on amount of acreage and associated oil and gas development potential. Protective measures for other resources, including limiting or prohibiting access and development or controlling the timing or nature of development, would result in adverse impacts. Restrictions on oil and gas development under each of the alternatives also would result in adverse impacts to the rate of oil and gas exploration, development, and extraction. These impacts would increase costs, both to the operator and the product end user, of exploring for, developing, and extracting oil and gas. Under all alternatives, operators must employ BMPs in the exploration, development, production, and abandonment of oil and gas resources.
Under all alternatives, areas administratively unavailable to oil and gas leasing would be closed to geophysical exploration and areas open to oil and gas leasing would be open to geophysical exploration. Managing areas as administratively unavailable would prohibit oil and gas exploration and subsequent development and extraction. This would result in adverse impacts to exploration and development of fluid mineral resources. Alternatively, allowing geophysical exploration in areas open to oil and gas development would result in beneficial impacts to oil and gas exploration and development. Requiring geophysical exploration to be performed within the constraints necessary to protect other resources (e.g., NSO or CSU restrictions) may result in adverse impacts to oil and gas exploration, but could benefit other resources. Adverse impacts to exploration would include increased costs to the operator from the use of more expensive, but less surface‐disturbing techniques (e.g., small, portable foot‐ or helicopter‐transported surveying equipment in areas with surface use restrictions). If surface use restrictions prevent an operator from effectively surveying/exploring oil and gas resources, development could be sited based on incomplete information, affecting the potential success of a future well. This also could result in increased costs to the operator and in nonproductive disturbances to land and surface resources.
In areas where federal oil and gas leases are or have been issued without stipulations, subsequently placing additional mitigation measures on exploration and development may result in adverse impacts to ongoing or future oil and gas development. Requiring additional stipulations on new leases may constrain exploration, development, production, or other actions that increase the timeframe and cost of operations. Mitigating measures attached to an APD as COA influence how an activity is accomplished, but rarely preclude the activity. Such management actions in complex areas involving impact avoidance to several resources may limit oil and gas operations.
Special designations (e.g., ACECs, NHTs, WSAs) and other management areas (e.g., recreation management areas) may result in adverse impacts to oil and gas exploration and development, depending on their location in relation to oil and gas development potential. These lands may be subject to a variety of restrictions related to oil and gas exploration or development, or require certain BMPs or mitigation to preserve resource and management objectives in these areas. Restrictions, subject to buffer zones of varying sizes, affecting oil and gas include restrictions that close or make these areas administratively unavailable, NSO restrictions over all or portions of specific areas, or CSU restrictions. Special stipulations, such as required resource surveys, also may be applied. Discussions of overall constraints for oil and gas for each alternative capture impacts from these special designations. Respective sections in this chapter discuss specific impacts of the management for each area.
Management actions that prescribe certain BMPs and mitigation would affect all alternatives on a project-specific basis, depending on the overall constraints under each alternative. While specific mitigation measures generally would be consistent, the nature and level of impacts to oil and gas development would vary among alternatives and may also vary based on site-specific conditions that would be evaluated in implementation-level environmental documents. In general, constraints on exploration, development, production, and abandonment of oil and gas resources (e.g., NSO, CSU, or TLS) would increase project timeframes and costs, and may limit the number of well pads and amount of surface disturbance on a lease. This would be an adverse impact. However, such constraints may result in beneficial impacts to other resources in a given area.
Under all alternatives, implementing mitigation measures to reduce air quality emissions from current levels and applying BMPs for oil and gas activities that could affect groundwater resources would require certain technologies and mitigation that may increase project costs. This would result in adverse impacts to oil and gas development.
On split-estate lands (areas with private surface ownership and federal mineral estate), determination of access road and well pad locations in conjunction with the surface owner may result in adverse impacts to oil and gas exploration or development. Such adverse impacts may result from an increase in the timeframe for processing and developing leases, increasing project costs, or the potential relocation of well pads and infrastructure. However, such consultations also could benefit an oil and gas operation in the long term as a result of the benefits of collaborating with the surface owner.
When necessary to protect important habitats, the BLM would attach COA for operations proposed on existing oil and gas leases within areas designated as unavailable for leasing, which would exclude surface occupancy and surface disturbance. The BLM would do this to the maximum extent possible without violating lease rights. Such restrictions on occupancy and surface disturbance may limit the operator’s ability to extract the federal oil and gas resources under lease. For example, directional drilling from an area outside such a lease to an operator-targeted bottom-hole location in a leased area may not be technically or economically feasible.
Under all alternatives, the BLM would require special status species inventories for surface-disturbing projects in known or suspected special status species habitat. Postponing or modifying projects that may affect special status species would lead to a delay in the development and/or the relocation of well pads, access roads, pipelines, or ancillary facilities.
Typical impacts from cultural resource management actions on oil and gas exploration and development would include increased well development costs associated with cultural resource inventories, relocation of projects (well pads, roads, pipelines) to avoid a cultural site, implementation of offsite drilling (directional drilling) techniques, and/or site excavation if avoidance is not possible. Discovery of previously undocumented cultural features during project construction would delay project implementation while the site is evaluated.
Under all alternatives, management actions for ROWs would allow, limit, or prohibit facilities and infrastructure necessary for the development and extraction of oil and gas resources including access roads, powerlines, and pipelines. This would impact oil and gas development. Federal regulations require ROW grants for access roads, powerlines, or pipelines that cross one lease to access another. Avoiding or excluding these authorizations could limit or prohibit legal access and infrastructure to well pads. Management that limits or prohibits ROW authorizations (ROW avoidance/mitigation and exclusion areas) would result in adverse impacts to oil and gas development. Designating ROW corridors up front could eliminate or reduce land use conflicts and beneficially affect oil and gas development and pipelines.
Oil and gas exploration and development often occur in grazing allotments. Oil and gas operators would have to abide by mitigation specified in lease stipulations or in the COA for those operations. Mitigation measures required to minimize adverse impacts to livestock grazing would increase the cost of oil and gas exploration and development. These measures would include providing for the upkeep and repair of fences and gates and taking measures to prevent loss of or injury to livestock. The BLM would not expect livestock mitigation to substantially affect the technical or economic viability of oil and gas development.
Reclaiming areas of surface disturbance with native grass and forb species to prevent erosion; monitoring and treating weeds and other nonnative, invasive plant species that occupy areas disturbed by oil and gas development and production; and returning vegetation and habitat to pre-disturbance conditions is required in all cases, increasing project costs.
Under all alternatives, the extent of impacts to oil and gas development from constraints and limitations on exploration and development relates directly to oil and gas development potential in an area. Management actions that constrain development of oil and gas in high-potential areas generally would result in more impacts to development than similar management actions that constrain development in low-potential areas. The RFD for oil and gas describes the potential for oil and gas occurrence and development in the Planning Area (BLM 2009e).
Under Alternative A, 154,861 acres of BLM-administered mineral estate would be administratively unavailable for mineral leasing (Map 17). Managing areas as administratively unavailable for oil and gas leasing would reduce the amount of land available for oil and gas leasing and prohibit development in these areas. This would result in direct adverse impacts to oil and gas development.
Under Alternative A, 1,399,490 acres of federal mineral estate are open to oil and gas leasing subject to the terms and conditions of the standard lease form and major constraints (Map 17). Major constraints to oil and gas exploration and development, such as NSO restrictions or overlapping TLS restrictions, limit or prohibit development in these areas or require certain drilling techniques, BMPs, or other mitigation. This results in adverse impacts to oil and gas exploration and development. In some cases, operations can be modified to accommodate such restrictions, but these modifications can be costly, increase project timeframes, or be otherwise undesirable to oil and gas operators. Companies typically drill oil and gas wells vertically because the costs are lower and drilling problems are less likely, but they could employ directional drilling in an area with an NSO restriction to protect other resources. For example, an operator might be able to place a well pad, access road, or production facility in a less sensitive area and drill the well directionally to recover reserves underlying the area with the NSO if under certain conditions, such as favorable geologic and drilling conditions. However, even if technically feasible, the increased costs associated with directional drilling may make some drilling activities uneconomical. Because directional drilling has certain limitations, operators may not be able to develop all the oil and gas resources from all the acreage associated with large NSO areas. Companies typically cannot use directional drilling to develop CBNG because the reservoirs are too shallow (BLM 2009e). Because of the costs associated with restrictions, an operator may decide to not develop oil and gas resources in an area with major constraints.
Under Alternative A, 1,789,634 acres of federal mineral estate are open to oil and gas leasing subject to the terms and conditions of the standard lease form and moderate constraints (Map 17). Moderate constraints limit the time of construction and operation activities or require specific mitigation or lease stipulations. This would result in adverse impacts to oil and gas leasing. Moderate constraints do not necessarily remove the area from development or exploration of oil and gas or require directional drilling. Under TLS restrictions, development may become more intensive over a shorter period to complete operations before timing restrictions apply. In areas with overlapping TLS restrictions, companies may be limited to narrow timeframes to complete work, which may result in major constraints. In some cases, an operator may have to start development and then postpone operations during specific periods. If the window during which work can be done is too short, a development project may have to proceed in phases, requiring more time to complete, adding to the project’s cost, and increasing the time before the investment is recovered. CSU restrictions could require specific lease stipulations to meet other resource management objectives and make the development of oil and gas uneconomical or unattractive to potential operators.
Under Alternative A, 863,564 acres of federal mineral estate are open to oil and gas leasing subject to the terms and conditions of the standard lease form only (Map 17). Managing areas open to oil and gas exploration and development allows oil and gas leasing and development in these areas with only standard lease stipulations. This would result in beneficial impacts.
As a result of the oil and gas constraints under Alternative A, projected drilling is reduced from the baseline unconstrained projections. The baseline scenario projects 1,354 federal wells could be drilled in the Planning Area. These include 1,249 conventional wells and 105 CBNG wells. Under Alternative A, 1,130 wells are projected (1,045 conventional wells and 85 CBNG wells). This represents an approximately 17-percent decrease from the baseline, or 204 fewer federal conventional wells and 20 fewer federal CBNG wells. Under Alternative A, 181 fewer federal oil and gas wells are expected to remain in production at the end of the planning period compared to the projected baseline scenario. This represents an approximately 5-percent decrease from the baseline scenario. Abandonment of federal wells is expected to decrease slightly (approximately 5 percent), from 957 wells under the baseline scenario, to 914 wells under Alternative A (BLM 2009e).
Designating ROW exclusion and avoidance/mitigation areas would prohibit or limit ROW authorizations for roads, pipelines, or other infrastructure that may be necessary for the development of oil and gas resources. This would result in adverse impacts to oil and gas development. Under Alternative A, the BLM manages 941,778 acres as ROW avoidance/mitigation areas and 61,416 acres as ROW exclusion areas.
Special designations (ACECs, NHTs, WSAs, and WSRs) under Alternative A may result in adverse impacts to oil and gas exploration and development. However, because these areas are generally small, the impacts to overall use of oil and gas resources would generally be limited. In addition to WSAs, Alternative A makes portions of some ACECs and some WSR eligible waterway segments administratively unavailable for oil and gas leasing (Table 4-6). Alternative A also manages areas within ¼ mile of the Nez Perce (Neeme-poo) NHT and Other Historic Trails, seven WSR eligible waterway segments, and the Red Gulch Dinosaur Tracksite ACEC, Big Cedar Ridge, Five Springs Falls, and Upper Owl Creek ACECs as available for oil and gas leasing with an NSO restriction.
Under Alternative A, restrictions and constraints on oil and gas development would result from management actions to protect resources. The most extensive impacts to oil and gas leasing from management of resources under Alternative A would result from restrictions for greater sage-grouse, raptor nesting, and big game crucial winter range.
Under Alternative A, adverse impacts to oil and gas development would result from management of greater sage-grouse leks, nesting and early brood-rearing habitat, and winter concentration areas on new and existing leases, including:
CSU restrictions within ¼ mile of occupied leks (30,886 acres)
TLS restrictions in early brood-rearing habitats within 2 miles of occupied leks (1,009,963 acres)
TLS restrictions in identified nesting and brood-rearing habitat outside the 2-mile buffer from March 15 to July 15 (CYFO seasonal restrictions are from February 1 to July 31)
TLS restrictions within winter concentration areas from November 15 to March 14
Under Alternative A, adverse impacts to oil and gas development would result from management of greater sage-grouse leks, nesting and early brood-rearing habitat, and winter concentration areas on new and existing leases, including:
These restrictions would impose moderate constraints to oil and gas development, which would result in adverse impacts. The impacts of these restrictions would vary across the Planning Area, depending on the projected development potential for oil and gas resources. For BLM-administered lands, management that constrains oil and gas development around greater sage-grouse leks, in nesting and early brood-rearing habitat, and in winter concentration areas would affect approximately 115,458 acres of moderate-potential areas, 521,785 acres of low-potential areas, and 522,797 acres of very-low-potential areas. Restrictions applied in low- and very-low-potential areas may result in only limited impacts to oil and gas development. Impacts to oil and gas development from restrictions that constrain development in moderate-potential areas would be greater than restrictions that constrain development in low- and very-low-potential areas.
Under Alternative A, restrictions on surface disturbances (i.e., TLS stipulations) in raptor nesting areas would prohibit development or require lease stipulations that may make oil and gas development more difficult. This would result in adverse impacts to oil and gas resources. Under Alternative A, designated raptor nest buffer areas would include approximately 338,731 acres of BLM-administered surface. Timing restrictions on surface-disturbing activities in these areas would narrow the available time for construction activities and potentially increase project costs. This may adversely affect oil and gas development. Under Alternative A, TLS restrictions for raptor nesting areas would occur on approximately 47,358 acres with moderate oil and gas development potential, 149,432 acres with low potential, and 126,181 acres with very low potential. As with oil and gas restrictions for greater sage-grouse habitat, impacts from TLS restrictions for raptor nest areas in moderate-potential areas would be greater than restrictions in low- and very-low-potential areas.
Under Alternative A, TLS restrictions in big game crucial winter range (1,313,731 acres) and big game parturition habitat (81,770 acres) would reduce the time available for oil and gas activities and potentially increase project timeframes and costs. This would result in adverse impacts to oil and gas resources. In addition, applying CSU restrictions for big game migration corridors, narrow ridges, overlapping big game crucial winter range (319,522 acres), and big game parturition habitat (81,770 acres) in the Absaroka Front Area would require lease stipulations that may increase project timeframes and costs. This would result in adverse impacts to oil and gas resources.
Alternative A prohibits surface-disturbing activities within 500 feet of surface water and riparian/wetland areas (55,586 acres). Prohibiting surface disturbance in these areas would exclude ROWs in these areas and prohibit the development of oil and gas resources, which would result in adverse impacts to oil and gas development.
Of the areas available for oil and gas leasing, 326,950 acres are in VRM Class II areas, 884,962 are in VRM Class III areas, and 1,793,466 are in VRM Class IV areas. In VRM Class I areas, the level of change to the characteristic landscape should be very low; therefore, VRM Class I areas are closed to oil and gas leasing. In VRM Class II areas, the level of change to the characteristic landscape should be low. Oil and gas exploration and development activities may be restricted or limited in VRM Class II areas. VRM objectives in Class II areas may limit the development of facilities. If the BLM approves oil and gas development in these areas, siting, design, and other mitigation may be required to ensure that management objectives for visual resources are met. Objectives for VRM Class III, Class IV, or unclassified area generally allow activities, subject to some level of mitigation.
The nature and extent of impacts to the oil and gas resources from VRM would vary according to the projected oil and gas development potential of the subject lands. Of the areas available for oil and gas leasing, VRM Class II areas include approximately 14,128 acres with a moderate potential for oil and gas resources, approximately 42,428 acres with a low potential for oil and gas resources, and approximately 245,815 acres with a very low potential for oil and gas resources. Impacts to oil and gas development from management as VRM Class II would be greater in moderate-potential lands than in low- and very-low-potential lands, because moderate-potential lands are more likely to be developed than low- and very-low-potential lands.
Under Alternative B, geophysical exploration is subject to limitations on motorized vehicle use and restrictions on surface‐disturbing activities. This would result in adverse impacts to oil and gas development by limiting the access and methods used for oil and gas resource surveys.
Under Alternative B, 2,296,279 acres of BLM-administered mineral estate would be administratively unavailable for mineral leasing (Map 18). Managing areas as administratively unavailable to mineral leasing would result in adverse impacts similar to those described for Alternative A, although to a greater extent. Implementing Alternative B would result in a substantial increase in area administratively unavailable to oil and gas leasing compared to Alternative A (154,861 acres), Alternative C (147,760 acres), and Alternative D (291,294 acres).
Under Alternative B, 1,320,277 acres of federal mineral estate are open to oil and gas leasing subject to the terms and conditions of the standard lease form and major constraints (Map 18). Managing areas with major constraints would result in adverse impacts similar to those described for Alternative A, although to a slightly lesser extent due to smaller acreage. Implementing Alternative B would result in a 6-percent decrease in area managed with major constraints compared to Alternative A, a 496-percent increase compared to Alternative C, and a 1,019-percent increase compared to Alternative D.
Under Alternative B, 451,948 acres of federal mineral estate are open to oil and gas leasing subject to the terms and conditions of the standard lease form and moderate constraints (Map 18). Managing areas with moderate constraints would result in adverse impacts similar to those described for Alternative A, although to a lesser extent. Implementing Alternative B would result in a 75-percent decrease in area managed with moderate constraints compared to Alternative A, a 79-percent decrease compared to Alternative C, and an 87-percent decrease compared to Alternative D. Managing more area as unavailable to mineral leasing and with major and moderate oil and gas constraints would likely result in increased oil and gas development on private lands under Alternative B, compared to the other alternatives.
Under Alternative B, 139,045 acres of federal mineral estate are open to oil and gas leasing subject to the terms and conditions of the standard lease form only (Map 18). Managing areas as open to oil and gas leasing subject to the standard lease form would result in beneficial impacts to oil and gas resources similar to those described for Alternative A, although to a lesser extent. Implementing Alternative B would result in an 84-percent decrease in area open subject to the standard lease form compared to Alternative A, a 92-percent decrease compared to Alternative C, and a 46-percent decrease compared to Alternative D.
As a result of the restrictions implemented under Alternative B, projected drilling is reduced from baseline projections. The baseline scenario projects that 1,354 federal wells could be drilled (1,249 conventional wells and 105 CBNG wells). Under Alternative B, 509 wells are projected (470 conventional wells and 39 CBNG wells). This represents an approximately 62-percent decrease from the baseline, or 779 fewer federal conventional wells and 66 fewer federal CBNG wells. Six-hundred eighty-three (683) fewer federal wells (both conventional and CBNG) are expected to remain in production at the end of the planning period. This represents an approximately 20-percent decrease from the baseline. Abandonment of federal wells is similarly expected to decrease (approximately 17 percent) from 957 wells under the baseline scenario to 795 wells under Alternative B (BLM 2009e). At the end of the planning period, projected total producing wells would be the least under Alternative B (2,680) compared to Alternative A (3,182), Alternative C (3,283), and Alternative D (3,100).
Under Alternative B, the BLM does not suspend existing non-producing oil and gas leases in areas closed to mineral leasing and, after such leases expire, would not offer the land for future leasing. This management may result in adverse impacts to the production of federal oil and gas where such resources are present. The respective terms (expiration dates) of such leases cannot be halted at the direction or consent (after application for suspension by the lessee or operator) of the BLM authorized officer, as would be the case if the leases were suspended. This would be the case even if lease suspension was in the interest of conservation of natural resources, encouraged the greatest ultimate recovery of oil and gas, or met other criteria warranting lease suspension (see 43 CFR 3135.2).
Managing areas as ROW avoidance/mitigation and exclusion areas would result in adverse impacts similar to those described for Alternative A, although to a greater extent. Under Alternative B, the BLM manages 2,717,617 acres as ROW avoidance/mitigation areas and 225,750 acres as ROW exclusion areas. The total acreage managed as ROW avoidance/mitigation and exclusion is greater than under the other alternatives.
Under Alternative B, geophysical exploration is subject to limitations on motorized vehicle use. Areas closed to motorized vehicle use (136,474 acres) and areas where motorized vehicle use is limited to designated roads and trails (2,054,228 acres) would restrict access routes in the Planning Area and may limit the use of seismic technology to obtain subsurface stratigraphic and structural information useful for exploration of oil and gas reserves. This would result in adverse impacts to oil and gas development.
Compared to the other alternatives, Alternative B includes more special designations and management areas (including recreation management areas) and places more restrictions on surface-disturbing activities in these areas. This results in more adverse impacts to the development of oil and gas resources. Management in these areas includes closing land to mineral leasing, and NSO and CSU restrictions. Because these areas are larger and have more restrictions, impacts to oil and gas exploration and development are expected to be more extensive than under the other alternatives. Table 4-6 shows the acreage of closures and areas administratively unavailable for oil and gas leasing due to special designations and other management areas under this alternative. Other impacts from these special designations (NSOs, TLS, and CSUs) are captured in the overall constraints for oil and gas under this alternative described above, and specific management for each area (e.g., ACECs or SRMAs) is discussed in its respective section.
Restrictions and constraints on oil and gas development resulting from management actions to protect resources would be the greatest under Alternative B. The most extensive impacts to oil and gas leasing from management of resources under Alternative B would result from restrictions for greater sage-grouse, raptor nesting, and big game crucial winter range.
Under Alternative B, quantitative air quality modeling of oil and gas field development would be required to determine potential impacts from proposed emissions sources. Air quality modeling of potential oil and gas development may require mitigation strategies for projects that would exceed emission standards.
The most extensive impacts to oil and gas leasing would result from protective restrictions for greater sage-grouse. Under Alternative B, adverse impacts to oil and gas development would result from management of greater sage-grouse leks, nesting and early brood-rearing habitat, and winter concentration areas on future and existing leases including:
TLS restrictions in nesting and early brood-rearing habitat within 3 miles of occupied leks (1,571,115 acres) from February 1 to July 31
TLS restrictions in nesting and early brood-rearing habitat outside the 3-mile lek buffer from February 1 to July 31
CSU restrictions for all seasonal habitats identified above to allow 1 to 15 acres of well location or 15 acres of habitat removal per 640-acre section
Also under Alternative B, adverse impacts to oil and gas development on new leases would result from:
NSO restrictions in 0.6 mile of occupied greater sage-grouse leks (157,008 acres)
NSO restrictions in winter concentration areas from November 15 to March 14
The designation of greater sage-grouse Key Habitat Areas as administratively unavailable to mineral leasing (1,226,064 acres)
These restrictions would result in adverse impacts by prohibiting oil and gas development or managing areas with moderate or major constraints to development. The impacts of these restrictions would vary across the Planning Area, depending on the projected development potential for oil and gas. For BLM-administered lands, management that constrains oil and gas development around greater sage-grouse leks, in nesting and early brood-rearing habitat, and in winter concentration areas would affect approximately 186,560 acres of moderate-potential areas, 822,520 acres of low-potential areas, and 797,395 acres of very-low-potential areas. Restrictions applied in low- and very-low-potential areas may result in only limited impacts to oil and gas development. Impacts to oil and gas development from restrictions that constrain development in moderate-potential areas would be greater than restrictions that constrain development in low- and very-low-potential areas. Because these constraints would affect a larger area of moderate development potential than under the other alternatives, adverse impacts to oil and gas from management of greater sage-grouse would be greater under Alternative B than under the other alternatives.
Limiting noise sources at the perimeter of occupied greater sage-grouse leks may require mitigation or technologies that reduce noise levels, which may increase project costs. This may result in adverse impacts to oil and gas development. Oil and gas development activities may be restricted where sound levels cannot be limited below ambient noise levels.
Under Alternative B, restrictions on surface disturbance (including TLS and CSU restrictions) in raptor nesting areas would result in adverse impacts to oil and gas development similar to those described for Alternative A, although to a greater extent due to restrictions in the increased buffer areas. Under Alternative B, raptor nest buffer areas would include approximately 570,506 acres of BLM-administered surface with both CSU and TLS restrictions, which represents an approximately 68-percent increase in area with restrictions compared to Alternative A. Restrictions in raptor nesting areas would occur on approximately 72,659 acres of moderate oil and gas development potential lands, 246,164 acres of low-potential lands, and 201,583 acres of very-low-potential lands. As a result of specific stipulations for ferruginous hawks, lands where greater sage-grouse and raptor habitats overlap could be subject to development restrictions for most of the year (9 months).
Managing big game crucial winter range (1,313,731 acres) and parturition habitat (81,770 acres) with an NSO restriction would prevent surface occupancy for oil and gas activities, and increase project costs or in some cases result in the inability to access oil and gas resources. This would result in adverse impacts to oil and gas exploration and development. These impacts would be greater under Alternative B than under Alternative A, which manages these areas with TLS restrictions. Managing the Absaroka Front Management Area (106,354 acres) as administratively unavailable to oil and gas leasing would prohibit oil and gas development in this area, which would result in adverse impacts.
Impacts to oil and gas from prohibiting surface disturbance within ¼ mile of riparian/wetland areas (140,464 acres) would result in impacts similar to those described for Alternative A, but to a greater extent due to larger acreages.
Under Alternative B, impacts to oil and gas development from VRM would be similar to those described for Alternative A, although to a greater extent due to more acreage managed as VRM Class I and Class II. Of the areas available for oil and gas leasing, 523,744 acres are in VRM Class II areas, 234,102 acres are in VRM Class III areas, and 554,398 acres are in VRM Class IV areas. The nature and extent of impacts to oil and gas exploration and development from VRM would vary according to the projected development potential of the subject lands. Under Alternative B, of the areas available for oil and gas leasing, VRM Class II areas include approximately 32,756 acres of moderate oil and gas development potential lands, approximately 263,941 acres of low-potential lands, and approximately 214,789 acres of very-low-potential lands. Under Alternative B, VRM Class II areas in moderate development potential areas increase by approximately 132 percent compared to Alternative A.
Under Alternative C, 147,760 acres of BLM-administered mineral estate would be administratively unavailable for mineral leasing (Map 19). Managing areas as administratively unavailable to mineral leasing would result in adverse impacts similar to those described for Alternative A, although to a lesser extent. Implementing Alternative C would result in a decrease in areas administratively unavailable compared to implementation of Alternative A (154,861 acres), Alternative B (2,296,279 acres), and Alternative D (291,294 acres).
Under Alternative C, 221,536 acres of federal mineral estate are open to oil and gas leasing subject to the terms and conditions of the standard lease form and major constraints (Map 19). Managing areas with major constraints would result in adverse impacts similar to those described for Alternative A, although to a lesser extent. Implementing Alternative C would result in an 84-percent decrease in area managed with major constraints compared to Alternative A, an 83-percent decrease compared to Alternative B, and an 88-percent increase compared to Alternative D.
Under Alternative C, 2,175,814 acres of federal mineral estate are open to oil and gas leasing subject to the terms and conditions of the standard lease form and moderate constraints (Map 19). Managing areas with moderate constraints would result in adverse impacts similar to those described for Alternative A, although to a greater extent. Implementing Alternative C would result in a 22-percent increase in area managed with moderate constraints compared to Alternative A, a 381-percent increase compared to Alternative B, and a 39-percent decrease compared to Alternative D.
Under Alternative C, 1,662,439 acres of federal mineral estate are open to oil and gas leasing subject to the terms and conditions of the standard lease form only (Map 19). Managing areas as open to oil and gas leasing subject to the standard lease form would result in beneficial impacts to oil and gas resources similar to those described under Alternative A though to a greater extent. Implementing Alternative C would result in a 93 percent increase in area open subject to the standard lease form compared to Alternative A, a 1,096 percent increase compared to Alternative B, and a 546 percent increase compared to Alternative D.
As a result of the restrictions implemented under Alternative C, projected drilling is reduced from the baseline projections. The baseline scenario projects that 1,354 federal wells could be drilled (1,249 conventional wells and 105 CBNG wells). Under Alternative C, 1,257 wells are projected (1,178 conventional wells and 79 CBNG wells). This represents an approximately 7-percent decrease from the baseline, or 71 fewer federal conventional wells and 26 fewer federal CBNG wells. Under Alternative C, 80 fewer federal wells (both conventional and CBNG) are expected to remain in production at the end of the planning period than projected in the baseline scenario. This represents an approximately 2-percent decrease. Abandonment of federal wells is expected to decrease slightly (approximately 2 percent), from 957 wells under the baseline scenario, to 940 wells under Alternative C (BLM 2009e). Projected total producing wells at the end of the planning period would be the greatest under Alternative C (3,283) compared to Alternative A (3,182), Alternative B (2,680), and Alternative D (3,100).
Under Alternative C, the BLM allows suspension of existing oil and gas leases (producing and non-producing) in areas closed to mineral leasing for reasons such as conservation of natural resources, greatest ultimate recovery of oil and gas, or other reasons outlined by regulation (see 43 CFR 3135.2). If the BLM authorized officer grants a suspension, the respective terms (expiration dates) of such leases are extended for the period of suspension. If the BLM authorized officer does not suspend existing non-producing oil and gas leases and allows them to expire, the BLM would not offer lands in these areas for future leasing. This management may result in adverse impacts to production of federal oil and gas where such resources are present. The BLM automatically extends the terms on producing leases (and leases capable of production) in paying quantities if they comply with applicable regulations (see 43 CFR 3107.2).
Under Alternative C, managing areas as ROW avoidance/mitigation or exclusion areas would result in adverse impacts similar to those described for Alternative A, although to a greater extent. Under Alternative C, the BLM manages more acreage (1,174,335 acres) as ROW avoidance/mitigation areas and less acreage (7,762 acres) as ROW exclusion areas. However, the total acreage managed as ROW avoidance/mitigation or exclusion is greater than under Alternative A and less than under alternatives B and D.
Alternative C prescribes fewer restrictions on surface-disturbing and disruptive activities for a smaller number of special designation and management areas (including recreation management areas) compared to the other alternatives. Fewer special designations and fewer restrictions in these areas would result in fewer adverse impacts to oil and gas exploration and development compared to the other alternatives. Table 4-6 shows the acreage of closures and areas administratively unavailable for oil and gas leasing due to special designations and other management areas under this alternative. Other impacts from these special designations (NSOs, TLS, and CSUs) are captured in the overall constraints for oil and gas under this alternative described above, and the specific management for each area (e.g., ACECs or SRMAs) is discussed in its respective section.
Restrictions and constraints on oil and gas development resulting from management actions to protect resources would be the least under Alternative C. The most extensive impacts to oil and gas leasing from resource management under Alternative C would result from restrictions for greater sage-grouse and raptor nesting areas.
Under Alternative C, there would be adverse impacts to oil and gas development resulting from management of greater sage-grouse leks, nesting and early brood-rearing habitat, and winter concentration areas on new and existing leases (excluding Oil and Gas Management Areas for TLS), including:
CSU restrictions within ¼ mile of occupied greater sage-grouse leks
TLS restrictions in greater sage-grouse nesting and early brood-rearing habitat within 2 miles of occupied leks (982,832 acres) from March 15 to July 15
TLS restrictions in nesting and brood-rearing habitat outside the 2-mile buffer from March 15 to July 15
TLS restrictions within greater sage-grouse winter concentration areas from November 15 to March 14
These restrictions would impose moderate constraints to oil and gas development, therefore resulting in adverse impacts. The impacts of these restrictions would vary across the Planning Area, depending on the projected development potential for oil and gas. For BLM-administered lands, management that constrains oil and gas development around greater sage-grouse leks and in nesting and early brood-rearing habitat and winter concentration areas would affect approximately 115,458 acres of moderate oil and gas development potential areas, 521,785 acres of low-potential areas, and 522,797 acres of very-low-potential areas. These restrictions affect the same area as Alternative A and would therefore result in similar impacts.
Limiting noise sources at the perimeter of occupied greater sage-grouse leks would result in adverse impacts to oil and gas development similar to those described for Alternative B, although to a lesser extent due to the reduced time that this stipulation would apply and the exemption of oil and gas management areas from this stipulation.
Raptor nest buffer areas are smaller under Alternative C, occupying approximately 82,294 acres of the Planning Area as a whole. Approximately 53,336 acres of BLM-administered surface are within raptor nest buffer areas. These lands are subject to TLS stipulations prohibiting surface-disturbing or disruptive activities within ¼ mile of active nests from February 1 through July 31. Raptor nesting areas affect approximately 7,908 acres with moderate oil and gas development potential lands, 20,056 acres with low-potential lands, and 17,144 acres with very-low-potential lands.
Alternative C would result in the least impact from wildlife restrictions. Alternative C exempts Oil and Gas Management Areas (568,164 acres) and ROW corridors from discretionary wildlife seasonal stipulations, and opens the Absaroka Front Management Area (106,354 acres) to oil and gas leasing and development, unlike alternatives B and D, which restrict oil and gas development in the area to protect wildlife habitat.
In contrast to the other alternatives, Alternative C would not prohibit or require avoidance of surface-disturbing activities in flood plains or riparian/wetland areas. Instead, the BLM authorizes surface-disturbing activities in these areas on a case-by-case basis, resulting in the fewest adverse impacts to oil and gas development in these areas of any alternative.
The types of impacts to oil and gas development from VRM would be similar to those described for Alternative A, although the extent of these impacts would be smaller because the BLM manages less area as VRM Class I and Class II under this alternative. Of the areas available for oil and gas leasing, 322,539 acres are in VRM Class II areas, 508,329 acres are in VRM Class III areas, and 2,181,175 acres are in VRM Class IV areas. The nature and extent of impacts from VRM on oil and gas exploration and development would vary according to the development potential of the subject lands. Of the areas available for oil and gas leasing, VRM Class II areas include approximately 1,888 acres with moderate oil and gas development potential. Approximately 17,619 acres are classified as low-potential lands and approximately 265,094 acres are classified as very-low-potential lands. Under Alternative C, VRM Class II areas in moderate development potential areas decrease by approximately 87 percent compared to Alternative A.
Establishing Oil and Gas Management Areas (Map 21; 568,164 acres) around intensively developed existing fields (Map 23) would allow for full development of known oil and gas resources in existing field areas. This would result in beneficial impacts to oil and gas exploration and development. The BLM would manage these areas primarily for oil and gas exploration and development and consider all other surface uses secondary. Exempting Oil and Gas Management Areas and ROW corridors from discretionary wildlife seasonal stipulations would result in beneficial impacts to oil and gas development and associated infrastructure in these areas. Oil and gas operators would be able to work in these areas throughout the year, which may provide some stability to what would otherwise be cyclic development due to wildlife-based seasonal restrictions.
Under Alternative D, geophysical exploration is subject to limitations on motorized vehicle use and restrictions on surface‐disturbing activities, resulting in similar adverse impacts as Alternative B.
Under Alternative D, 291,294 acres of BLM-administered mineral estate would be administratively unavailable for mineral leasing (Map 20). Managing areas as administratively unavailable to mineral leasing would result in adverse impacts similar to those described for Alternative A, although to a slightly greater extent. Implementing Alternative D would result in an increase in area administratively unavailable compared to Alternative A (154,861 acres) and Alternative C (147,760 acres).
Under Alternative D, 117,968 acres of federal mineral estate are open to oil and gas leasing subject to the terms and conditions of the standard lease form and major constraints (Map 20). Managing areas with major constraints would result in adverse impacts similar to those described for Alternative A, although to a lesser extent. Implementing Alternative D would result in a 92-percent decrease in area managed with major constraints compared to Alternative A, a 91-percent decrease compared to Alternative B, and a 47-percent decrease compared to Alternative C.
Under Alternative D, 3,540,775 acres of federal mineral estate are open to oil and gas leasing subject to the terms and conditions of the standard lease form and moderate constraints (Map 20). Managing areas with moderate constraints would result in adverse impacts similar to those described for Alternative A, although to a greater extent. Implementing Alternative D would result in a 98-percent increase in area managed with moderate constraints compared to Alternative A, a 683-percent increase compared to Alternative B, and a 63-percent increase compared to Alternative C.
Under Alternative D, 257,512 acres of federal mineral estate are open to oil and gas leasing subject to the terms and conditions of the standard lease form only (Map 20). Managing areas as open to oil and gas leasing subject to the standard lease form would result in beneficial impacts to oil and gas resources similar to those described for Alternative A, although to a lesser extent. Implementing Alternative D would result in a 70-percent decrease in area open subject to the standard lease form compared to Alternative A, an 85-percent increase compared to Alternative B, and an 85-percent decrease compared to Alternative C.
As a result of the restrictions implemented under Alternative D, projected drilling is reduced from the baseline projections. The baseline scenario projects that 1,354 federal wells could be drilled (1,249 conventional wells and 105 CBNG wells). Under Alternative D, 1,032 wells are projected (979 conventional wells and 53 CBNG wells). This represents an approximately 24-percent decrease from the baseline, or 270 fewer federal conventional wells and 52 fewer federal CBNG wells. Under Alternative D, 263 fewer federal wells (both conventional and CBNG) are expected to remain in production at the end of the planning period than projected in the baseline scenario. This represents an approximately 8-percent decrease. Abandonment of federal wells is expected to decrease (approximately 6 percent) from 957 wells under the baseline scenario, to 898 wells under Alternative D (BLM 2009e). The projected number of total producing wells at the end of the planning period under Alternative D (3,100) would be less than under Alternative C (3,283) and Alternative A (3,182), but more than under Alternative B (2,680).
Under Alternative D, the BLM prohibits the suspension of existing, non-producing oil and gas leases on a case-by-case basis in areas closed to mineral leasing, resulting in impacts similar to those under Alternative B.
Managing areas as ROW avoidance/mitigation and exclusion areas would result in adverse impacts similar to those described for Alternative A, although to a greater extent. Under Alternative D, the BLM manages more acreage (2,512,202 acres) as ROW avoidance/mitigation areas but less acreage (39,003 acres) as ROW exclusion areas. The total acreage managed as ROW avoidance/mitigation or exclusion areas is more than under alternatives A and C, but less than under Alternative B.
Geophysical exploration is subject to limitations on motorized vehicle use under Alternative D, which would result in impacts similar to Alternative B, although to a lesser extent because less area is closed or limited to designated roads and trails.
Alternative D closes more areas to mineral leasing and prescribes more restrictions on surface-disturbing and disruptive activities for special designations and management areas (including Wild Lands) than alternatives A and C, but less than Alternative B. Management in these areas includes closing land to mineral leasing, and NSO and CSU restrictions. Impacts from restrictions in special designations would be similar to those under Alternative A, although to a greater extent because of the size of the affected area. Table 4-6 shows the acreages of closures and areas administratively unavailable for oil and gas leasing due to special designations and other management areas under this alternative. Other impacts from these special designations (NSOs, TLS, and CSUs) are captured in the overall constraints for oil and gas under this alternative described above, and the specific management for each area (e.g., ACECs or SRMAs) is discussed in its respective section.
Restrictions and constraints on oil and gas development resulting from management actions to protect resources would adversely impact oil and gas leasing under Alternative D. The most extensive impacts from management of resources under Alternative D would result from restrictions for greater sage-grouse and raptor nesting.
Under Alternative D, constraints on resource uses in greater sage-grouse Key Habitat Areas would be more restrictive to oil and gas development than constraints outside Key Habitat Areas, and therefore would result in greater adverse impacts. Managing greater sage-grouse leks, nesting and early brood-rearing habitat, and winter concentration areas inside Key Habitat Areas (Map 34) includes:
CSU stipulation to prohibit or restrict surface-disturbing activities or surface occupancy within 0.6 mile of occupied or undetermined sage-grouse leks (125,843 acres)
TLS stipulation to restrict disruptive activity within 0.6 mile of occupied or undetermined sage-grouse leks from 6 pm to 8 am from March 1 to May 15 (125,843 acres)
TLS to prohibit or restrict surface-disturbing and/or disruptive activities in suitable sage-grouse nesting and early brood-rearing habitat within Key Habitat Areas from March 1 to June 30
TLS to prohibit or restrict surface-disturbing and disruptive activities in mapped or modeled sage-grouse winter habitats/concentration areas that support Key Habitat Area populations from November 15 to March 14
Managing greater sage-grouse leks, nesting and early brood-rearing habitat, and winter concentration areas outside Key Habitat Areas (Map 34) includes:
CSU stipulation to prohibit or restrict surface-disturbing activities or surface occupancy within ¼ mile of occupied or undetermined sage-grouse leks (5,802 acres)
TLS stipulation to restrict disruptive activity within ¼ mile of occupied or undetermined sage-grouse leks from 6 pm to 8 am from March 1 to May 15 (5,802 acres)
TLS to prohibit or restrict surface-disturbing and/or disruptive activities in suitable sage-grouse nesting and early brood-rearing habitat within mapped habitat important for connectivity or within 2 miles of any occupied or undetermined lek (945,670 acres)
TLS to prohibit or restrict surface-disturbing and/or disruptive activities in mapped or modeled sage-grouse winter habitats/concentration areas from November 15 to March 14
These restrictions would impose moderate constraints to oil and gas development, resulting in adverse impacts. The impacts of these restrictions would vary across the Planning Area, depending on the projected development potential for oil and gas. For BLM-administered lands, management that constrains oil and gas development around greater sage-grouse leks, in nesting and early brood-rearing habitat, and in winter concentration areas in Key Habitat Areas would affect more acreage of moderate- and low-potential areas than alternatives A and C. However, outside Key Habitat Areas, Alternative D would likely impact oil and gas development potential lands similar to alternatives A and C.
Similar to Alternative B, Alternative D would limit noise sources at the perimeter of occupied greater sage-grouse leks; however, in contrast to Alternative B, Alternative D would only limit noise sources from 6 pm to 8 am. This would result in less adverse impact compared to Alternative B because noise restrictions would not limit daytime activities.
Restrictions on surface disturbance in raptor nesting areas under Alternative D would result in similar adverse impacts as those under Alternative A, although to a lesser extent due to smaller buffer areas. TLS and CSU restrictions around raptor nests, which vary by raptor species, would affect a total of 86,550 acres of BLM-administered surface. There would be restrictions in raptor nesting areas on approximately 9,700 acres of moderate oil and gas development potential lands, 40,866 acres of low-potential lands, and 31,842 acres of very-low-potential lands. As a result of specific stipulations for ferruginous hawks, lands where greater sage-grouse and raptor habitats overlap could be subject to development restrictions for most of the year (9 months).
Alternative D would apply TLS restrictions in big game crucial winter range (1,313,731 acres) and big game parturition habitat (81,770 acres), resulting in similar impacts as Alternative A. However, Alternative D would exempt Oil and Gas Management areas (134,214 acres) from discretionary big game seasonal stipulations. This would allow development of oil and gas resources in these areas without these restrictions and would result in beneficial impacts to oil and gas development. Managing the Absaroka Front Management Area (130,895 acres) with a mix of CSU, TLS, NSO, and unavailable for leasing stipulations would prohibit oil and gas development or require lease stipulations that may increase project timeframes and costs. This would be an adverse impact to oil and gas development.
Under Alternative D, surface-disturbing activities are avoided within 500 feet and up to ¼ mile if needed to protect sensitive resources of the waters of the state, perennial surface water, and riparian/wetland areas. Avoiding surface-disturbing activities would prohibit the activity unless the impacts could be mitigated, thus increasing project timeframes and costs associated with mitigation or making oil and gas resources in these areas uneconomical to develop. This would be an adverse impact on oil and gas development.
The types of impacts to oil and gas development from VRM under Alternative D would be similar to those described for Alternative A, although the extent of these impacts would be greater because more area is managed as VRM Class I and Class II under this alternative. Of the areas available for oil and gas leasing, 524,682 acres are in VRM Class II areas, 831,317 acres are in VRM Class III areas, and 1,556,111 acres are in VRM Class IV areas. The nature and extent of impacts from VRM to oil and gas exploration and development would vary according to the development potential of the subject lands. Of the areas available for oil and gas leasing, VRM Class II areas include approximately 18,619 acres defined as having moderate oil and gas development potential. Approximately 79,315 acres are classified as low-potential lands and approximately 407,906 acres are classified as very-low-potential lands. Under Alternative D, VRM Class II areas in moderate development potential areas increase by approximately 32 percent compared to Alternative A.
Alternative D designates Oil and Gas Management Areas on 134,214 acres of BLM-administered surface (433,950 acres less than under Alternative C) to be managed primarily for oil and gas exploration and development. Designating Oil and Gas Management Areas would result in similar, but less beneficial impacts, than Alternative C due to the reduced acreage under this alternative.