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OCT-01-2013 09:39 FROM:PARADISE BUSINESSCTR 18089652122 TO:9618912 P.7/24 —due to the low boiling point of these substances. It is the"working fluid"whit powers the turbine. The geothermal fluid remains enclosed within pipes and is reinjected into the res rvoir.'" During normal operations this type of plant does not expose the geothermal brine to the air. Con equently there is reported to be little harmful atmospheric emissions, liquid,or sludge wastes from this part of the binary production process_6' industry sources tout it as being ecologically clean and in 'cafe that future geothermal plants may employ these methods. f.lowever,atmospheric emissions till result during initial exploration drilling and well testing.Additionally,variances from emissions req rements may be needed during routine periodic maintenance and/or plant expansion,etc. Problems with s stem malfunctions and leaking pipes exist as well. Flammable Leaks The"working fluid"within the pipes,such as isobutane, is regulated with"permissible"levels for loss due to"fugitive" leaks. At the time ol'this writing,an allowable limit of 250 lbs./day has been established,with leaks of up to 10,000 parts per million(ppm)permitted before r pairs are required to be initiated to fix the leak_ Plant operators are allowed 15 days for repair completio before further reporting is required. Meanwhile operations can continue,despite unchecked leaking fluid•,''' Leak detection is required on a monthly basis. Isobutane is highly flammable.'In March, 1990, isobutane in a piping system at the Mammoth Lakes California plant ignited. Iwo workers conducting maintenance on the system were burned—one severely. The resulting tire burned for 16 hours. Fire suppression efforts involved fire-lighting personnel from six different agencies.Preliminary government and industry investigations determined no safety violations had occurred."° The-ire apparently was determined to be part of normal operations, with the plant meeting the requirements of permit regulations. allowing profitable energy production to continue relatively unabated. I he binary method of geothermal production was initially developed for use where reservoir fluid temperatures were low,requiring working fluids with a low boiling point,such as isobutane,Freon,etc. Binary,with its enclosed piping system,heat exchanger,and secondary fluids can be more costly to design and finance than other systems. In the economic profit/cost motivated energy production industry there are no guarantees that more costly methods,designs,and equipment—allo ing greater environmental protection and community/worker safety-will be utilized when I ss resource and time- costly methods are available. With the differing temperatures and composition of geothermal reservoirs, less maintenance intensive,or technologically more feasible methods may be utilized due to high heat, large quantities of particulate mutter.or corrosive fluids. Geothermal's Toxic Tea The corrosive nature of geothermal fluids,particularly their effect on vari',us metals, initially challenged technological capabilities and delayed exploitation,of geothermal as• energy source. ( eothermal fluids contain varied chemical substances; some highly toxic such as hydrogen sulfide, arsenic,and mercuiy—among others. Geothermal reservoirs are located in tecto iically active areas where fissures exist beneath the surface of the earth. Precipitation pooling helo the surface is heated by contact with hot rocks below,which are in turn heated by magma. Minerals,me . Is,and gases from deposits below the surface, mix with waters forming the composition of the gent canal brine or steam. 11w Jnl/nwing,' is a lot of geothermal pollutants, their various threshold limits anc'the toxicological c'l/ec! Health 'Effects of Air Pollutants from Geothermal Development 6 I