Preliminary environmental impact assessment of geothermal exploration and development in Karisimbi, Rwanda

Abstract

In this report a preliminary environmental impact assessment for geothermal exploration and development in the Karisimbi geothermal prospect is presented. In this study previous geoscientific data are reviewed, a prerequisite for choosing good sites for three exploration wells. Also, the possible threats of the proximity of the Karisimbi prospect to the mountain gorillas, whose habitat is within the National Volcanoes Park, are discussed. Even though geothermal energy is environmentally friendly, as much less CO2 is emitted than through the use of fossil fuels, it has adverse impacts on the environment. The immediate possible impacts on the mountain gorillas and other endemic and threatened species of animals will be caused by noise from well discharging and testing, and the unpleasant smell of hydrogen sulphide.

Exploration drilling has short term socioeconomic impacts and benefits on the local community. Therefore, geothermal fluid might be recycled for minimizing environmental pollution while directional drilling and re-injection of the fluid are proposed in the future. A full environmental impact assessment must be carried out prior to drilling and any potential impacts should be addressed before granting any permits. An integrated environmental monitoring program, involving all stakeholders, is recommended throughout all phases of the project. For such, information on the following is necessary: (i) knowledge of the movements of endangered species in the park, (ii) the level of geothermal gas emissions at all times and (iii) the opinion of the local people on the different kinds of disturbances and the benefits of the project.