Two shallow sub-surface CO2 controlled release experiments were conducted at the Ginninderra test site during 2012. The theme of the first experiment was CO2 detection in the soil and surface emissions quantification. The theme for the second experiment was investigating sub-surface migration and broad scale detection technologies. Our objective overall is to design cheaper monitoring technologies to evaluate leakage and environmental impact in the shallow sub-surface. Over 10 different monitoring techniques were evaluated at the site against a known CO2 release. These included soil gas, soil CO2 flux, soil analysis, eddy covariance, atmospheric tomography, noble gas tracers, ground penetrating radar, electromagnetic surveys, airborne hyperspectral, in-field phenotyping (thermal, hyperspectral and 3D imaging), and microbial soil genomics. Technique highlights and an assessment of the implications for large scale storage are presented in the following corresponding talks. Presented at the 2013 CO2CRC Research Symposium

Geoscience Australia and the CO2CRC have constructed a greenhouse gas controlled release facility at an experimental agricultural station maintained by CSIRO Plant Industry at Ginninderra, Canberra. The facility is designed to simulate surface emissions of CO2 from the soil into the atmosphere and is modelled on the ZERT controlled release facility in Montana. Injection of CO2 into the soil is via a 120 m long slotted HDPE pipe installed horizontally 2 m underground. An eddy covariance (EC) system was installed at Ginninderra during the first sub-surface release (March - June 2012). The EC system, which generated 15 minute averages using a 10 Hz sampling frequency, measured net radiation (as a function of upwelling and downwelling, solar and longwave radiation); wind speed and direction in 3 dimensions; CO2 and H2O concentration; and temperature and pressure. The EC system was installed to provide baseline atmospheric measurements and assess methods for quantifying CO2 leakages. The daily CO2 release rate was 100 kg/d. Here we report on the application of the CO2 emissions quantification method developed by Pan et al. (2010) for detecting and quantifying CO2 leakages using EC techniques. The approach seeks to isolate the CO2 leakage signal from the natural variation inherent in flux data, using a time-window splitting scheme, median filtering and scaling techniques. Results from application of the EC method at the Ginninderra site will be presented and modifications to the method and its limitations discussed. Pan, L.; Lewicki, J.L.; Oldenburg C.M.; and Fischer M.L., (2010). Time-window based filtering method for near-surface detection of leakage from geological carbon sequestration sites, Environmental Earth Sciences, 60, pp 359-369. Proceedings of the 2013 International Carbon Dioxide Conference - Beijing China