Bureau of Land Management's Decision Record and Environmental

Jersey Valley Geothennal Development Project
Environmental Assessment: NV063 -EAO8-09 1
The NDWR lists eight points of diversion for surface water rights located within the Jersey
Valley unit area. One of these is a certified irrigation right of 44.16 AFY from a stream source
located on private land in Section 34. The remaining seven are vested stock water rights totaling
237.72 AFY from springs located in Sections 28 and 29 which are associated with the Jersey Hot
Springs (NDCNR-DWR 2009b).
Ormat has collected and analyzed samples of geothermal fluid from several of the geothermal
wells drilled and flow-tested by Ormat as part of its exploration of the Jersey Valley unit area.
These produced geotheimal fluids are, like the Jersey Hot Springs, a sodium chloride/calcium
sulfate water, but with a substantially higher TDS concentration (approximately 2,600 ppm)
(Ormat 2008) (see Table 8). Boron concentrations averaged about 2.21 ppm.
3.9.2 Environmental Consequences
3.9.2.1 Proposed Action
The geothermal wells would be drilled using non-toxic drilling mud to prevent the loss of
drilling fluids into the rock and the risk of contamination to any aquifers from the drilling fluid.
Reserve pits would be constructed at each well site for the containment and temporary storage of
drilling mud, drill cuttings, geothermal fluid and storm water runoff from each constructed well
pad. Because non-toxic drilling mud would be used, the reserve pits are not proposed to be lined.
Additionally, the bentonite drilling muds discharged into the reserve pits would tend to act as a
liner, in the same way they prevent the loss of drilling fluids in the well bore into the rock.
Therefore, contamination of the local ground water aquifers as a result of the temporary
discharges into the reserve pits is unlikely.
Over the operational life of the project, accidental discharges of geothermal fluids could
contaminate surface or ground waters. However, these are unlikely because of the frequent
inspections and ultrasonic testing of the geothermal pipelines, the pipeline flow and pressure
monitoring and the well pump and pipeline valve shutdown features. Contamination of surface or
ground waters from spills of petroleum products (such as diesel fuel or lubricants) is also
unlikely because the well pads and power plant sites, where most petroleum products would be
used and stored, would be bermed to contain and control any spills. The project includes the
development of a spill and disposal contingency plan which would describe the methods for
cleanup and abatement of any petroleum hydrocarbon or other hazardous material spill.
During construction, the Jersey Valley Project would consume about 105 acre-feet of ground
water over the anticipated 12-month construction period, principally for geothermal well drilling
and dust control. This one-time quantity of construction water, obtained from existing private
water well source, is substantially less than the perennial yield estimated for the basin. Thus,
there is little potential for creating any adverse affects on the quantity of either surface waters or
ground waters in or adjacent to the geothermal operations area. The following monitoring
measure is proposed for the Jersey Valley project to verify the absence of adverse effects on the
quantity and quality of ground waters.
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