H2S and CO2 dispersion modelling for the Nesjavellir geothermal power plant, S-Iceland and preliminary geothermal environmental impact assessment for the Theistareykir area, NE-Iceland

Abstract

A prediction of H2S and CO2 dispersion by the Industrial Source Complex Model (ISC3View) in Nesjavellir geothermal power plant is presented. The results from the model show that the H2S and CO2 concentrations are lower than those specified in workplace standards. The highest concentrations during the study were observed in July and August, but they were lower than specified in NIOSH and ACGIH standards for H2S and CO2. In all cases higher concentrations of both gases were predicted towards the north and northwest. In the second part of the report a preliminary environmental impact assessment for a geothermal project in the Theistareykir area, in northeast Iceland is presented. This area has been investigated for geothermal resources by various researchers in the past few years due to interest in using geothermal steam. A preliminary review is carried out on possible environmental effects due to the proposed project in order to decide whether to carry out an environmental impact assessment (EIA) and disclose key impacts. In this study, an attempt has been made to identify the likely impact of geothermal exploration, drilling and operations, and potential mitigating measures. The result of this study suggests that detailed studies should be carried out on the water supply for drilling, on how to get rid of effluent water, and on the monitoring of gas emissions to the atmosphere during drilling and operations, as well as a detailed assessment of the biology of the area.