Allaying public concern regarding CO2 geological sequestration through the development of automated stations for the continuous geochemical monitoring of gases in the near surface environment

The principle concern for both regulators and the public at large regarding the large-scale application of on-shore geological carbon dioxide (CO2) sequestration is related to possible health risks due to the leakage of CO2 at surface. Development and "proof of concept" of the automated geochemical monitoring station during research is seen as an important step forward in providing tools that help in assuring the public at large about the safety of geological CO2 sequestration. The advances in microchip technology, portable analytical instrumentation, and decreasing prices means that, once fully developed, a significant number of these relatively low cost stations might be deployed above an injection site to monitor CO2 leaks. These might be particularly useful if placed around any deep wells that penetrate the reservoir or deep aquifer in which CO2 is being injected, as gas injection tests have shown how breakthrough of monitored gases is often first observed in the vicinity of the injection borehole, implying that fracturing during drilling provided preferential flow pathways. Preliminary data provided by the development and installation of a prototype automated geochemical-geophysical monitoring station in the San Vittorino area has shown that this technology exists and that it can provide, together with other techniques, a useful tool for the safety assessment and monitoring of geological sequestration sites. © 2005 Elsevier Ltd. All rights reserved.