| Abstract |
The Hawaii Geothermal Project is a multi disciplinary research effort with the major objectives of locating a suitable geothermal resource on the island of Hawaii and utilizing the heat to produce electricity by means of a research-oriented power plant. As a primary first step of this project, the potential geothermal resources on the island of Hawaii must be studied and sufficient information obtained to permit a reasonable prediction to be made of the behavior of the geothermal field, as well as the environmental impact of the utilization of the resources. The Hawaiian Islands were formed by volcanic action. high porosity and permeability of the basaltic formation, aquifers at shallow depth are likely to be unconfined from the top. tulated that a magma chamber at shallow depth and the numerous hot intrusives that form a dike complex can provide the heat source for the heating of the groundwater in the aquifer (Furumoto 1975). As the high permeability of the formation permits a continuous recharge from the ocean and rainfall, it has been speculated that most of the geothermal resource at shallow depth in the island is probably warm water at low or moderate temperatures (Macdonald 1973). layers are formed at great depth where hot water may be found (Furumoto 1975). As the basaltic rock hardly deforms under pressure, a large scale land surface subsidence resulting from the withdrawal of geothermal fluids is not anticipated. However, the utilization of geothermal resources in the island is not free from other adverse environmental impacts. The most serious potential hazard is the possibility of the contamination of the freshwater lens during the reinjection of the toxic fluids into the formation. The prediction of the fate of the injected fluids under different operating conditions thus merits careful consideration. |