What assurance can be provided that the CO2 will remain where it is stored?

The CCS process seeks to mimic natural processes that have held fluids underground for millions of years. Steps are taken to ensure that the process mimics the natural one as closely as possible and that CO2 sequestration is permanent. Those steps can be broadly broken down into four categories:

  • Site Selection
    • Potential CCS sites must be thoroughly assessed to determine whether the geology is appropriate for permanent sequestration.
  • Monitoring
    • During and after CO2 injection, a variety of techniques must be used concurrently to monitor the site and ensure CO2 remains in the sequestration formation deep underground.
  • Reporting
    • Results from monitoring are reported to the US EPA who ensures the project is functioning and being operated safely as planned.
  • Verification
    • Data gathered at the site must be compared to modeling simulations of the CO2 in the subsurface. Those models need to be refined based on observed data. Third parties may be called upon to verify that data and information reported by the project operator are accurate.