Environmental research needs for geothermal resources development. Volume I

A detailed analysis was conducted to determine the adequacy of the total research efforts regarding the potential environmental impacts related to the exploration, drilling, production, and transmission stages of vapor-dominated, liquid-dominated, geopressured, and hot-dry-rock geothermal resources. The following environmental considerations were selected and analyzed in detail: air emissions (hydrogen sulfide, ammonia, mercury, boron, radon, etc.); liquid emissions (brine, and toxic chemicals); land subsidence; seismic activity; and noise. Following the definition of the problem and the assessment of the past and ongoing research efforts, environmental research needs were then recommended based on: (1) the severity of the environmental problems as perceived by literature and contacts with the research community; (2) probability of occurrence; (3) and the research dependency for a solution to that particular problem. The recommended research needs consisted of: (1) an evaluation of the past and ongoing research efforts to ascertain gaps in knowledge for a particular pollutant, process, or control technology; (2) baseline studies of air, soil, water, and ecology around the existing geothermal facilities and in the locations scheduled for future geothermal development; (3) need for the development of appropriate models for predicting concentration and dispersion of pollutants; (4) development of predictive models for potential health and environmental effects associated with geothermal operations; and (5) development of appropriate control technology to destroy, remove or reduce harmful emissions in order to prevent the occurrence of environmental and health hazards and to comply with existing standards and criteria