Bureau of Land Management's Decision Record and Environmental

Jersey Valley Geothermal Development Project
Environmental Assessment: NV063 -EAO8 -091
Concentrated (3 5%) hydrochloric acid and 40% ammonium fluoride solution (to make the
hydrofluoric acid) would be delivered via truck to the site on use (i.e. would not be stored onsite
during well drilling and testing). The acids are mixed on site with water by experienced
contractors. The dilute acid mixture is placed in the cased well bore, followed by water to push
the mixture into the geothermal reservoir. After dissolving the minerals in the geothermal
reservoir, the water and now spent acids are flowed back through the well to the surface where
they are tested, neutralized if necessary (using sodium hydroxide or crushed limestone or
marble), and discharged to the reserve pit, which will be sampled prior to reclamation of the pit
(see Section 2.1.2).
The project must comply with BLM requirements to ensure that any geothermal fluid
encountered during the drilling does not flow uncontrolled to the surface. These include the use
of “blow-out” prevention equipment during drilling and the installation of well casing cemented
into the ground.
After drilling operations are completed, the liquids from the reserve pits would either naturally
evaporate, or be removed as may be necessary to reclaim the reserve pits. The non-hazardous,
non-toxic residual solid contents of the pits would be mixed with the excavated rock and soil and
buried by backfihling the reserve pit.
The small quantities of solid wastes (paper trash and garbage) generated by the project would be
transported offsite to an appropriate landfill facility. Portable chemical toilet wastes would be
removed by a local contractor. Given Ormat’s compliance with the associated lease stipulations,
no effects would result from solid wastes generated by the project (see also Section 2.1.11). The
disposal of these wastes would be a residual impact of the project.
Small quantities of hazardous waste would be generated by construction operations. Typically
these wastes would be in the form of empty drums or spent lead acid batteries used for
construction equipment. Construction activities typically generate waste oils, oily rags, and oil
impregnated absorbent materials used to clean up minor spills from construction equipment.
However, most waste generated from the construction activities would be solid (non-hazardous)
waste.
Hazardous materials stored on site during normal power plant operations include diesel fuel for
the fire pump and standby generator, lubricating oils, and small quantities of paint, antifreeze,
cleaning solvents, battery acid, transformer insulating fluid, and laboratory reagent chemicals.
Air pollution abatement chemicals and geothermal fluid handling chemicals will also be stored
on site. These materials will typically be stored within secondary containment and there will be
little potential for adverse effects from spills or releases of these materials.
Substantial quantities of the binary working fluid, pentane, would be stored and used (though not
consumed or intentionally released). Pentane is a flammable but non-toxic hydrocarbon similar
to, but less volatile than propane. During major maintenance activities on the pentane side of the
binary power plant units, the liquid pentane would first be transferred to the pentane storage
tank. However, not all of the pentane can be removed in this manner, and the residual pentane
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