U.S. Geothermal LLC (USGN) proposes to construct and drill two observation wells (OW11 & OW12,) with DOE funding in order to further evaluate the geothermal resource around their San Emidio Geothermal Facility and to reduce surface impacts, disturbance, cultural resource impacts, and exploration costs. The proposed project would also improve the data collected regarding optimal location of actual geothermal wells. These wells would be in addition to 5 Observation wells previously approved by a DNA on 12/22/2011 and in conjunction with six production wells permitted in October 2010. Well OW11 would be constructed on the existing well pad of well 52-4 (and would not extend outside the existing analyzed disturbance for well 52-4). Well OW12 would also be constructed on an existing well pad of well 58-33 (and would not extend outside the existing analyzed disturbance for well 52-4). Both well pads and the surrounding area were analyzed in the Wind Mountain Mine Well EA (1989) and under seismic line surveys performed for the San Emidio Geothermal Exploration Project EA (October 2010). Each seismic survey line had a cultural survey completed along its routes for a width of approximately 100 feet for the analysis of the October 2010 exploration EA. The existing well pads are approximately 100 feet x 150 feet or 0.34 acre. They each would include an 8 foot x 12 foot fenced sump, a modular mud tank and pump and shaker. The proposed wells have existing roads associated with them and will not require cross country travel. Nonetheless, the disturbance produced by each well pad would be no different than that of a Temperature Gradient Hole. The well construction activity would be located on BLM land in the southeast corner of township 30 north range 23 east and the northeast corner of township 29 north range 23 east in Washoe County. The proposed sites would be located on leases NVN74196 and NVN 75233, within the San Emidio Federal Unit NVN085820X. Total proposed surface disturbance for this project is estimated to be 0.68 acres.
Operations would be conducted as described in the ‘San Emidio Observation Wells OW-11 and OW-12 Drilling Program’ description submitted by USGN for this proposal. EA DOI-BLM-NV-W030-2010-006-EA analyzed disturbance and related potential impacts for six production well locations on public land. Total disturbance analyzed in the EA was 21.5 acres. Of this total disturbance analyzed the six already analyzed well pads would disturb approximately 15 acres, and the associated road building, surface piping placement, and test water ponds will create the remaining 6.5 acres of disturbance. Currently, no wells have been drilled on public lands under EA DOI-BLM-NV-W030-2010-006-EA, although the six wells have been permitted.