Bureau of Land Management's Decision Record and Environmental

Jersey Valley Geothermal Development Project
Environmental Assessment: NV063 -EAO8-09 1
4 CUMULATIVE EFFECTS
The CEQ regulations for implementing NEPA (40 CFR 1508.7) define cumulative impacts as:
“. . . the impact on the environment which results from the incremental impact of the action when
added to other past, present, or reasonably foreseeable future actions regardless of what agency
(Federal or non-Federal) or person undertakes such actions. Cumulative impacts can result from
individually minor but collectively significant actions taking place over a period of time.”
4.1 CUMULATIVE EFFECTS STUDY AREA
The cumulative effects study area (CESA) is the approximately 407,360 acre area which was
determined on a hydrologic and topographical basis (see Figure 23).
4.2. PAST AND PRESENT ACTIONS
Past and present actions consist primarily of livestock grazing, recreational activities,
transportation and access, wildfires, wild horse and burro use (including wild horse gathers),
mineral exploration and geothermal exploration activities.
Livestock grazing — Portions of seven BLM-managed grazing allotments are within the CESA:
North Buffalo, South Buffalo, Jersey Valley, Home Station Gap, Pumpernickel, Copper Canyon,
Cottonwood and Carico Lake (BLM, NV 2005). In order to support the management of these
allotments, a variety of range improvement projects have been implemented through the years,
including fences, cattleguards and wells.
Recreational activities — Dispersed recreation occurs within the CESA and includes off-highway
vehicle (OHV) use, wildlife viewing and hunting.
Transportation and access — Past and present actions within the CESA are supported by a
transportation system which includes gravel County Roads, BLM Roads, and dirt roads or
“two-tracks” on public lands. Few are regularly maintained.
Wildfires — Within the past decade there have been seven wildfires within the CESA: two
unnamed fires (1999 and 2000), the Gooseberry Fire (2001), Smelser Pass Fire (2006),
Cottonwood Fire (2006), the Buffalo Ranch Fire (2006) and the Horse Fire (2007) (BLM, MLFO
2006a).
Wild Horse and Burro Use — Portions of two BLM-managed Herd Management Areas (HMAs)
are within the CESA: Tobin Range HMA and the Augusta Mountains HMA (BLM, NV 2007).
Mineral exploration — Hundreds of active mining claims exist within the CESA.
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