The energy department will focus on large-scale injection of CO2 into deep saline formations and the potential for water displacement into shallow groundwater systems, while the EPA will concentrate on the migration of CO2 and its possible impact on underground sources of drinking water.
Tom Shope, Acting Assistant Secretary for the DOE's Office of Fossil Energy, said it was essential to ensure future CO2 storage is safe, free of harmful environmental affects and secure for hundreds and thousands of years.
He said as carbon sequestration technologies are implemented on a larger scale, it was expected that the amount of CO2 injected and sequestered underground will be extremely large as well.
"Making significant greenhouse gas reductions over the long term will require capturing and storing (sequestering) millions of tonnes," he said.
Research efforts to date have not evaluated what impact large-scale injection and related water displacement may have on the groundwater resources in various regions of the country.
DOE is funding four research tasks to better understand whether the large-scale increase of water pressure in CO2 storage formations may change the hydrologic conditions in shallow aquifers. This effort will specifically focus on any changes in groundwater table levels, effects on discharge and recharge zones in the groundwater systems and potential impacts of those changes on underground sources of drinking water.
The initial phase of the project will injection CO2 into a deep saline reservoir, below drinking water supplies, and conduct studies to determine the sensitivity of water displacement and pressure build up on a variety of saline reservoir parameters.
The project has already set up a reactive-transport simulation model to examine CO2 intrusion into a shallow aquifer and has conducted initial sensitivity studies involving geochemical system behavior and related mineralogy.
In addition, DOE has begun a data search evaluating the geochemical conditions in prominent reservoirs near potential sequestration sites, targeting the capture and permanent storage of CO2 from sources such as power plants in various regions of the country.
