Search

Search Results

• 1. [Image] Economic Impact of Geothermal Development : Sonoma and Lake Counties, California

  	The original purpose for the following text was to provide us at PgandE with a projection of the economic impact of The Geysers Power Plant and what effect its future development will have on the surrounding ...
  	Citation × Citation Citation Abstract Copy Title: Economic Impact of Geothermal Development : Sonoma and Lake Counties, California Author: Mahoney, D.J. Year: 1977 The original purpose for the following text was to provide us at PgandE with a projection of the economic impact of The Geysers Power Plant and what effect its future development will have on the surrounding communities Title: Economic Impact of Geothermal Development : Sonoma and Lake Counties, California Author: Mahoney, D.J. Year: 1977 The original purpose for the following text was to provide us at PgandE with a projection of the economic impact of The Geysers Power Plant and what effect its future development will have on the surrounding communities Close

• 2. [Image] Geothermal Resource Assessment, Kern River Canyon and Lake Isabella Area, Northeastern Kern County, California

  	A preliminary investigation was performed in northeastern Kern County in order to assess the low temperature geothermal resources. The objective was to develop an accurate inventory of the low temperature ...
  	Citation × Citation Citation Abstract Copy Title: Geothermal Resource Assessment, Kern River Canyon and Lake Isabella Area, Northeastern Kern County, California Author: International Engineering Company, Incorporated Year: 1984 A preliminary investigation was performed in northeastern Kern County in order to assess the low temperature geothermal resources. The objective was to develop an accurate inventory of the low temperature resources and to identify alternatives for the direct use of these resources. Emphasis was placed on six areas exhibiting thermal manifestations in the Lake Isabella area and Kern River Canyon. Other reports in this study will identify applications and examine legislative, social, economic, technical and environmental barriers to the development of these resources. This report addresses Task 1 and includes: identification of the areas, preliminary analyses of each resource, interviews with resource owners, an update on information of the springs and a preliminary evaluation of the exploitation potential Title: Geothermal Resource Assessment, Kern River Canyon and Lake Isabella Area, Northeastern Kern County, California Author: International Engineering Company, Incorporated Year: 1984 A preliminary investigation was performed in northeastern Kern County in order to assess the low temperature geothermal resources. The objective was to develop an accurate inventory of the low temperature resources and to identify alternatives for the direct use of these resources. Emphasis was placed on six areas exhibiting thermal manifestations in the Lake Isabella area and Kern River Canyon. Other reports in this study will identify applications and examine legislative, social, economic, technical and environmental barriers to the development of these resources. This report addresses Task 1 and includes: identification of the areas, preliminary analyses of each resource, interviews with resource owners, an update on information of the springs and a preliminary evaluation of the exploitation potential Close

• 3. [Image] Low -Altitude Aeromagnetic Survey of a Portion of the Coso Hot Springs KGRA, Inyo County, California

  	A detailed low-altitude aeromagnetic survey of 576 line-mi (927 line-km) was completed over a portion of the Coso Hot Springs KGRA in September 1977. The survey has defined a pronounced magnetic low that ...
  	Citation × Citation Citation Abstract Copy Title: Low -Altitude Aeromagnetic Survey of a Portion of the Coso Hot Springs KGRA, Inyo County, California Author: Fox, R.C. Year: 1978 A detailed low-altitude aeromagnetic survey of 576 line-mi (927 line-km) was completed over a portion of the Coso Hot Springs KGRA in September 1977. The survey has defined a pronounced magnetic low that could help delineate the geothermal system. The magnetic low has an areal extent of approximately 10 C' sq mi (26 sq km). Direct and indirect evidence indicates that this anomaly is due, in part, to magnetite destruction by hydrothermal solutions associated with the geothermal system. The anomaly generally coincides with two other geophysical anomalies which are directly associated with the system: 1) a bedrock electrical resistivity low, and 2) an area of relatively high near-surface temperatures. The highest measured heat flow, 18 HFU, also occurs within its boundary. The magnetic low occurs at the intersection of two major structural zones which coincide with a complementary set of strike-slip fault zones determined from seismic activity. The intersection of these two zones of active tectonism probably served as the locus for emplacement of a pluton at depth, above which are observed the coincidental geophysical anomalies and surface manifestations related to the geothermal system Title: Low -Altitude Aeromagnetic Survey of a Portion of the Coso Hot Springs KGRA, Inyo County, California Author: Fox, R.C. Year: 1978 A detailed low-altitude aeromagnetic survey of 576 line-mi (927 line-km) was completed over a portion of the Coso Hot Springs KGRA in September 1977. The survey has defined a pronounced magnetic low that could help delineate the geothermal system. The magnetic low has an areal extent of approximately 10 C' sq mi (26 sq km). Direct and indirect evidence indicates that this anomaly is due, in part, to magnetite destruction by hydrothermal solutions associated with the geothermal system. The anomaly generally coincides with two other geophysical anomalies which are directly associated with the system: 1) a bedrock electrical resistivity low, and 2) an area of relatively high near-surface temperatures. The highest measured heat flow, 18 HFU, also occurs within its boundary. The magnetic low occurs at the intersection of two major structural zones which coincide with a complementary set of strike-slip fault zones determined from seismic activity. The intersection of these two zones of active tectonism probably served as the locus for emplacement of a pluton at depth, above which are observed the coincidental geophysical anomalies and surface manifestations related to the geothermal system Close

• 4. [Image] Characteristics of Geothermal Wells Located in the Salton Sea Geothermal Field, Imperial County, California

  	We have summarized the geophysical, geochemical, and geothermal characteristics of wells located in the Salton Sea Geothermal Field. Based on the geothermal characteristics of the wells, we have developed ...
  	Citation × Citation Citation Abstract Copy Title: Characteristics of Geothermal Wells Located in the Salton Sea Geothermal Field, Imperial County, California Author: Palmer, T.D. Year: 1975 We have summarized the geophysical, geochemical, and geothermal characteristics of wells located in the Salton Sea Geothermal Field. Based on the geothermal characteristics of the wells, we have developed a subsurface heat profile for the entire geothermal field. We have also drawn maps of temperature contours for specified depths throughout the field Title: Characteristics of Geothermal Wells Located in the Salton Sea Geothermal Field, Imperial County, California Author: Palmer, T.D. Year: 1975 We have summarized the geophysical, geochemical, and geothermal characteristics of wells located in the Salton Sea Geothermal Field. Based on the geothermal characteristics of the wells, we have developed a subsurface heat profile for the entire geothermal field. We have also drawn maps of temperature contours for specified depths throughout the field Close

• 5. [Image] Dipole-Dipole Resistivity Survey of a Portion of the Coso Hot Springs KGRA, Inyo County, California

  	A detailed electrical resistivity survey of 54 line-km was completed at the Coso Hot Springs KGRA in September 1977. This survey has defined a bedrock resistivity low at least 4 sq mi (10 sq km) in extent ...
  	Citation × Citation Citation Abstract Copy Title: Dipole-Dipole Resistivity Survey of a Portion of the Coso Hot Springs KGRA, Inyo County, California Author: Fox, R.C. Year: 1978 A detailed electrical resistivity survey of 54 line-km was completed at the Coso Hot Springs KGRA in September 1977. This survey has defined a bedrock resistivity low at least 4 sq mi (10 sq km) in extent associated with the geothermal system at Coso. The boundaries of this low are generally well defined to the north and west but not as well to the south where an approximate southern limit has been determined. The bedrock resistivity low merges with an observed resistivity low over gravel fill east of Coso Hot Springs. A complex horizontal and vertical resistivity structure of the surveyed area has been defined which precludes the use of layered-earth or two-dimensional interpretive models for much of the surveyed area. In general the survey data indicate that a 10 to 20 ohm-meter zone extends from near surface to a depth greater than 750 meters within the geothermal system. This zone is bordered to the north and west by bedrock resistivities greater than 200 ohm-meters and to the south by bedrock resistivities greater than 50 ohm-meters. A combination of observed increases in: (1) fracture density (higher permeability), (2) alteration (high clay content), and (3) temperatures (higher dissolved solid content of ground water) within the bedrock low explain its presence Title: Dipole-Dipole Resistivity Survey of a Portion of the Coso Hot Springs KGRA, Inyo County, California Author: Fox, R.C. Year: 1978 A detailed electrical resistivity survey of 54 line-km was completed at the Coso Hot Springs KGRA in September 1977. This survey has defined a bedrock resistivity low at least 4 sq mi (10 sq km) in extent associated with the geothermal system at Coso. The boundaries of this low are generally well defined to the north and west but not as well to the south where an approximate southern limit has been determined. The bedrock resistivity low merges with an observed resistivity low over gravel fill east of Coso Hot Springs. A complex horizontal and vertical resistivity structure of the surveyed area has been defined which precludes the use of layered-earth or two-dimensional interpretive models for much of the surveyed area. In general the survey data indicate that a 10 to 20 ohm-meter zone extends from near surface to a depth greater than 750 meters within the geothermal system. This zone is bordered to the north and west by bedrock resistivities greater than 200 ohm-meters and to the south by bedrock resistivities greater than 50 ohm-meters. A combination of observed increases in: (1) fracture density (higher permeability), (2) alteration (high clay content), and (3) temperatures (higher dissolved solid content of ground water) within the bedrock low explain its presence Close

• 6. [Image] Fourmile Hill Geothermal Development Project: Environmental Impact Statement, Environmental Impact Report, Final EIS/EIR Executive Summary

  	The Fourmile Hill Geothermal Development Project would be located in eastern Siskiyou and western Modoc Counties, California, on the Klamath and Modoc National Forests and within the Glass Mountain Known ...
  	Citation × Citation Citation Abstract Copy Title: Fourmile Hill Geothermal Development Project: Environmental Impact Statement, Environmental Impact Report, Final EIS/EIR Executive Summary Author: Bureau of Land Management Year: 1998 The Fourmile Hill Geothermal Development Project would be located in eastern Siskiyou and western Modoc Counties, California, on the Klamath and Modoc National Forests and within the Glass Mountain Known Geothermal Resource Area (I<GRA). Calpine Corporation proposes to develop a 49.9 megawatt geothermal power plant and Wellfield and a 24-mile, 23O-kilovolt transmission line. The Glass Mountain KGRA, which is designated by the US. Geological Survey, is one of the only remaining undeveloped KGRAs in North America with a demonstrated geothermal resource. Based on the analysis presented in the Final Environmental Impact Statement and Environmental Impact Report (EIS/EIR), the project, after mitigation, would have a significant adverse effect on the environment on traditional cultural values and visual resources. After mitigation, the project would not have any other significant adverse effects on the environment. Effects on visual resources would be avoided by proposed alternatives. Effects on traditional cultural values would be unavoidable. The project could also result in significant cumulative effects through conflicts with religious use of the area by local tribal members. Potentially significant cumulative effects in the Medicine Lake area would be avoided by the preferred alternative. The Final EIS/EIR is distributed for a 30-day notification period that begins October 2 and ends November 2, 1998 Title: Fourmile Hill Geothermal Development Project: Environmental Impact Statement, Environmental Impact Report, Final EIS/EIR Executive Summary Author: Bureau of Land Management Year: 1998 The Fourmile Hill Geothermal Development Project would be located in eastern Siskiyou and western Modoc Counties, California, on the Klamath and Modoc National Forests and within the Glass Mountain Known Geothermal Resource Area (I<GRA). Calpine Corporation proposes to develop a 49.9 megawatt geothermal power plant and Wellfield and a 24-mile, 23O-kilovolt transmission line. The Glass Mountain KGRA, which is designated by the US. Geological Survey, is one of the only remaining undeveloped KGRAs in North America with a demonstrated geothermal resource. Based on the analysis presented in the Final Environmental Impact Statement and Environmental Impact Report (EIS/EIR), the project, after mitigation, would have a significant adverse effect on the environment on traditional cultural values and visual resources. After mitigation, the project would not have any other significant adverse effects on the environment. Effects on visual resources would be avoided by proposed alternatives. Effects on traditional cultural values would be unavoidable. The project could also result in significant cumulative effects through conflicts with religious use of the area by local tribal members. Potentially significant cumulative effects in the Medicine Lake area would be avoided by the preferred alternative. The Final EIS/EIR is distributed for a 30-day notification period that begins October 2 and ends November 2, 1998 Close

• 7. [Image] Geotechnical Studies of Geothermal Reservoirs

  	Maximum temperatures found in the reservoir were approximately 700°F in the Imperial Valley, California, but drill bit temperatures may be considerably higher in the Geysers geothermal area. Temperatures ...
  	Citation × Citation Citation Abstract Copy Title: Geotechnical Studies of Geothermal Reservoirs Author: Pratt, H. R. Year: 1976 Maximum temperatures found in the reservoir were approximately 700°F in the Imperial Valley, California, but drill bit temperatures may be considerably higher in the Geysers geothermal area. Temperatures reached up to 900°F because of frictional heating and possibly inefficient cooling. Rock types found in the high temperature environments range from hard abrasive granites and metamorphosed sandstones to unconsolidated sediments and friable sandstones. The rocks are highly fractured at reservoir depths Title: Geotechnical Studies of Geothermal Reservoirs Author: Pratt, H. R. Year: 1976 Maximum temperatures found in the reservoir were approximately 700°F in the Imperial Valley, California, but drill bit temperatures may be considerably higher in the Geysers geothermal area. Temperatures reached up to 900°F because of frictional heating and possibly inefficient cooling. Rock types found in the high temperature environments range from hard abrasive granites and metamorphosed sandstones to unconsolidated sediments and friable sandstones. The rocks are highly fractured at reservoir depths Close

• 8. [Image] Geological and Geophysical Analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California

  	The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California, from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and ...
  	Citation × Citation Citation Abstract Copy Title: Geological and Geophysical Analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California Author: Galbraith, R.M. Year: 1978 The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California, from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and extensive geophysical logging surveys were conducted to document the geologic character of the geothermal system as penetrated by CGEH-1. The major rock units encountered include a mafic metamorphic sequence and a leucogranite which intruded the metamorphic rocks. Only weak hydrothermal alteration was noted in these rocks. Drillhole surveys and drilling rate data indicate that the geothermal system is structurally controlled and that the drillhole itself was strongly influenced by structural zones. Water chemistry indicates that this geothermal resource is a hot-water rather than a vapor-dominated system. Several geophysical logs were employed to characterize the drillhole geology. The natural gamma and neutron porosity logs indicate gross rock type and the acoustics logs indicate fractured rock and potentially permeable zones. A series of temperature logs run as a function of time during and after the completion of drilling were most useful in delineating the zones of maximum heat flux. Convective heat flow and temperatures greater than 350/sup 0/F appear to occur only along an open fracture system encountered between depths of 1850 and 2775 feet. Temperature logs indicate a negative thermal gradient below 3000 feet Title: Geological and Geophysical Analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California Author: Galbraith, R.M. Year: 1978 The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California, from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and extensive geophysical logging surveys were conducted to document the geologic character of the geothermal system as penetrated by CGEH-1. The major rock units encountered include a mafic metamorphic sequence and a leucogranite which intruded the metamorphic rocks. Only weak hydrothermal alteration was noted in these rocks. Drillhole surveys and drilling rate data indicate that the geothermal system is structurally controlled and that the drillhole itself was strongly influenced by structural zones. Water chemistry indicates that this geothermal resource is a hot-water rather than a vapor-dominated system. Several geophysical logs were employed to characterize the drillhole geology. The natural gamma and neutron porosity logs indicate gross rock type and the acoustics logs indicate fractured rock and potentially permeable zones. A series of temperature logs run as a function of time during and after the completion of drilling were most useful in delineating the zones of maximum heat flux. Convective heat flow and temperatures greater than 350/sup 0/F appear to occur only along an open fracture system encountered between depths of 1850 and 2775 feet. Temperature logs indicate a negative thermal gradient below 3000 feet Close

• 9. [Image] Potential of Low-Temperature Geothermal Resources in Northern California. Report No. TR13

  	Economically feasible uses for geothermal heat at temperatures too low for conventional electrical power generation at present are delineated. Several geothermal resource areas in northern California that ...
  	Citation × Citation Citation Abstract Copy Title: Potential of Low-Temperature Geothermal Resources in Northern California. Report No. TR13 Author: Hannah, J.L. Year: 1975 Economically feasible uses for geothermal heat at temperatures too low for conventional electrical power generation at present are delineated. Several geothermal resource areas in northern California that have development potential are described, and applications of the heat found in each area are suggested. Plates are included of the following field study areas: the east side of the Sierra-Cascade Range north of Bishop, and the northern Coast Range from San Francisco Bay to Clear Lake. The counties included in the study area are Mo doc, Lassen, Sierra, Plumas, Placer, Alpine, Mono, Mendocino, Lake, and Sonoma. (LBS) Title: Potential of Low-Temperature Geothermal Resources in Northern California. Report No. TR13 Author: Hannah, J.L. Year: 1975 Economically feasible uses for geothermal heat at temperatures too low for conventional electrical power generation at present are delineated. Several geothermal resource areas in northern California that have development potential are described, and applications of the heat found in each area are suggested. Plates are included of the following field study areas: the east side of the Sierra-Cascade Range north of Bishop, and the northern Coast Range from San Francisco Bay to Clear Lake. The counties included in the study area are Mo doc, Lassen, Sierra, Plumas, Placer, Alpine, Mono, Mendocino, Lake, and Sonoma. (LBS) Close

• 10. [Image] Balancing Energy and the Environment: The Case of Geothermal Development

  	The results of part of a Rand study on the federal role in resolving environmental issues arising out of the implementation of energy projects are reported. The projects discussed are two geothermal programs ...
  	Citation × Citation Citation Abstract Copy Title: Balancing Energy and the Environment: The Case of Geothermal Development Author: Ellickson, P.L. Year: 1978 The results of part of a Rand study on the federal role in resolving environmental issues arising out of the implementation of energy projects are reported. The projects discussed are two geothermal programs in California: the steam resource development at The Geysers (Lake and Sonoma counties) in northern California, and the wet brine development in the Imperial Valley in southern California Title: Balancing Energy and the Environment: The Case of Geothermal Development Author: Ellickson, P.L. Year: 1978 The results of part of a Rand study on the federal role in resolving environmental issues arising out of the implementation of energy projects are reported. The projects discussed are two geothermal programs in California: the steam resource development at The Geysers (Lake and Sonoma counties) in northern California, and the wet brine development in the Imperial Valley in southern California Close