(142b) Risk-Based Monitoring, Reporting, and Verification of Geological Carbon Dioxide Storage

Over 50 years ago, storage of carbon dioxide (CO₂) in geologic rock formations was commercialized for use in a technique known as carbon dioxide enhanced oil recovery (CO₂ EOR). Enhanced oil recovery, or tertiary recovery, refers to injection of previously recovered CO₂ into depleted reservoirs to re-pressurize them for further oil & gas extraction. Continued use of CO₂ EOR and further innovations in these techniques have paved the way for CO₂ storage at a larger scale. Furthermore, sustainability goals set forth by the United States government and evolving regulations on greenhouse gas emissions have encouraged a growing interest in carbon capture, utilization, and storage (CCUS) technologies, of which an important part is carbon storage.

The use of geologic formations for carbon storage in the U.S. is extremely viable, with capacity for over 3,000 metric gigatons of CO₂ in domestic formations compared to the average production of 5.3 gigatons per year.[1] However, much remains unknown regarding the long-term safety of geological carbon storage. The majority of existing CO₂ storage facilities utilize depleted oil & gas reservoirs, while future developments will require use of deep saline aquifers, which have wider geographical distribution and larger storage resources.[2] In recognition of this transition, the EPA put forth federal requirements under the Underground Injection Control (UIC) Program for Carbon Dioxide Geologic Sequestration Wells as a part of the Safe Drinking Water Act (SDWA), which includes requirements for the development of monitoring, reporting, and verification (MRV) plans of any wells that inject CO₂ for long-term containment in subsurface geologic formations.[3]

Because permitting for the development of long-term storage injection wells is a rigorous process, only four federal EPA-permitted Class VI injection wells are currently operating, with over 130 permits pending review.[4] However, problems have already begun to emerge. For example, in August 2024, the EPA issued a notice of violation of the SDWA to one facility due to movement of injected fluids into unauthorized zones.[5] As a result, public concerns have been raised regarding the long-term safety of CO₂ storage in geologic formations. To address these concerns, we discuss how the development of risk-based MRV plans may be harnessed to manage the risks associated with development of carbon dioxide storage sites. We also highlight the unique challenges associated with CO₂ storage siting and monitoring, along with existing regulations for the development of MRV plans.

[1] U.S. Geological Survey, “How much carbon dioxide can the United States store underground via geologic sequestration?,” https://www.americangeosciences.org/critical-issues/faq/geologic-carbon….

[2] Global CCS Institute, Fact Sheet on Geological Storage of CO₂: Safe, Permanent, and Abundant.

[3] 45 FR 42500, 75 FR 75078, 75 FR 77230.

[4] Congressional Research Service, Class VI Carbon Sequestration Wells: Permitting and State Program Primacy, April 16, 2024.

[5] Public Notice: ADM Geologic Sequestration Well – Proposed Order SDWA-05-2025-0001.