Novel MVA tools to track CO2 seepage, tested at the ZERT controlled release site in Bozeman, MT

Abstract

Over the past 4 years, controlled field experiments have taken place in Bozeman, MT, USA where pure CO2 has been released at known rates and depths to quantify the detection limits of various monitoring tools and techniques for the use of CO2 seepage detection. As part of this study, new tools engineered at Los Alamos National Laboratory were deployed to determine the sensitivity of these technologies to detect and measure CO2 seepage. These technologies were engineered for above-ground CO2 detection and include laser-based closed path δ13CO2 measurement systems, an O2/CO2 concentration ratio measurement system, and a chamber-based radon detection system. The sensitivity of these technologies to detect CO2 were measured through spatial transects taken perpendicular to the CO2 source and through temporal changes measured diurnally over the course of a 30 day experiment. Results show that the radon system is most sensitive to CO2 detection at the start of the experiment in locations adjacent to the CO2 source. The closed path or in situ δ13CO2 system detected CO2 seepage as far as 2 m away from the source during non-windy periods. The O2/CO2 system detected the CO2 seepage as far as 2 m above-ground and 1 m away from the source. Descriptions of these technologies and an overview of these results are presented. © 2010 Springer-Verlag.