Sound Pressure Level Measurements at and around the Las Pailas Geothermal Project and in Rincon de la Vieja National Park, Guanacaste, Costa Rica

Abstract

From September 2008 to June 2009, as part of a field investigation for a Masters degree in Natural Resource Management, sound pressure level measurements were made in the area under development for the Las Pailas Geothermal Project as well as within the north-bordering Rincón de la Vieja National Park and a region of open grasslands to the northwest in order to identify the environmental noise level (LA90) and the existing natural sources of noise. Las Pailas Geothermal Project is located on the Pacific slope of the Quaternary Rincón de la Vieja volcanic complex in northwestern Costa Rica and is expected to come on line with a 35 MWe powerhouse in 2011. Each noise level measurement was taken at 120 cm above the soil level at equally spaced observation points on a one-kilometer grid. Throughout the field area there are important differences in elevation, topographic gradient, and land use, all of which may influence the measured sound pressure levels. All of these data have been compiled in an Access database and integrated so that they may be visualilzed with Geographic Information System software. This paper presents new field data on naturally occurring sound pressure levels at and around the Las Pailas geothermal Project. Specifically, this paper addresses how environmental noise levels change with changing land use practices. These results may be utilized in the decision making process for future development of the Las Pailas Geothermal Project.