Modeling Potential Environmental Impacts of Deep Aquifer C02 Sequestration

Session H2: Water Resources Management and Planning - Modeling and Software for Improving Dcisions and Engaging Stakeholders

A promising measure for mitigating climate change is to store large volumes of C0₂ captured from large point-source carbon emitters in deep saline aquifers. In vulnerable systems, water resources impacts of large-scale C0₂ storage need to be evaluated and assessed before industrial­ size storage projects get under way. In California's southern San Joaquin Basin the land surface uplift caused by large C0₂ injection projects land deformation could have the potential to create reverse flow along certain canal reaches, or to reduce canal deliveries to agricultural land and managed wetlands. The impact of C0₂ storage on shallow water resources was compared to the expected stresses on the groundwater and surface water systems from ongoing pumping using a version of the Central Valley Hydrological Model CVHM extended vertically to capture reservoir geology. Results of simulations demonstrated that such pumping-related deformations in the area might be one order of magnitude larger than those from C0₂ injection. In the basin the low permeability geological layers between shallow effectively limit pressure changes from migrating far in vertical directions, downward or upward.