New Mexico Geological Society Annual Spring Meeting — Abstracts

The Bravo Dome Field, located in Union and Harding counties, New Mexico, is a large underground carbon dioxide reserve that is one of the largest CO₂ accumulations in North America. This field provides jobs for about 100 people, as well as $1.8 million in tax revenues and royalties for the state annually. The carbon dioxide is primarily used to enhance recovery in the oil fields of SE New Mexico and western Texas. Although the region's economy relies heavily upon the production of carbon dioxide, residents living on the eastern boundary of the field have expressed concern about the health effects associated with possibly elevated levels of carbon dioxide. In July and August of 2002, a field survey was conducted to investigate the possible natural leakage of carbon dioxide from the Bravo Dome Field on ranches near the town of Amistad where health related complaints were reported to the states Environmental and Health departments. Atmospheric carbon dioxide concentrations were continuously monitored using a Drager CO₂ analyzer. Soil carbon dioxide concentrations were measured in several locations as well. Ambient atmosphere contains approximately 0.036% (by volume) CO₂, and measured atmospheric CO₂ concentrations in the study area remained consistently at 0.03%. Soil carbon dioxide concentrations ranged from 0.47% in sparsely vegetated areas to 1.0% in densely vegetated lawns. These measurements did not significantly differ from background measurements taken approximately 20 miles north of the CO₂ field. No elevated CO₂ concentrations were found in houses, near pipelines or the compressor plant. At Mammoth Mountain, California soil CO₂ concentrations are significantly larger (>30% by volume), yet CO₂ related illnesses are rarely reported. We found no evidence for the presence of elevated CO₂ levels and alternative explanations must be found to account for the illnesses experienced in the Amistad area.