Climate Change
Carbon Dioxide Capture and Sequestration
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What is carbon dioxide capture and sequestration?
Quick Fact
What's the difference between carbon dioxide capture and sequestration (CCS) and geologic sequestration?
Geologic sequestration is one step in the CCS process. Unlike terrestrial, or biologic, sequestration, where carbon is stored via agricultural and forestry practices, geologic sequestration involves injecting carbon dioxide deep underground where it stays permanently.
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EPA's Proposed Carbon Pollution Standards for New Power Plants
On March 27, 2012, the Environmental Protection Agency (EPA) proposed Carbon Pollution Standards for New Power Plants. This common-sense step under the Clean Air Act would, for the first time, limit the amount of carbon pollution that new power plants can emit and ensure that new facilities take advantage of clean technologies. Carbon capture and sequestration is one of the technologies new power plants can employ to meet the standard. Learn more about the proposed standards.
Carbon dioxide (CO2) capture and sequestration (CCS), also known as carbon capture and storage, is a set of technologies that can greatly reduce CO2 emissions from new and existing coal- and gas-fired power plants, industrial processes, and other stationary sources of CO2. CCS is a three-step process that includes:
- Capture of CO2 from power plants or industrial sources
- Transport of the captured and compressed CO2 (usually in pipelines)
- Underground injection and geologic sequestration, or permanent storage, of the CO2 in rock formations that contain tiny openings - or pores - that trap and hold the CO2
Another important part of CCS is monitoring to verify that the CO2 remains permanently underground.
Learn more about how CCS works.
Why is it important?
Carbon dioxide (CO2) capture and sequestration (CCS) offers a way for the United States and other countries to capture and store emissions of CO2 from large stationary sources such as power plants and to reduce the risks associated with severe climate change. The U.S. Department of Energy estimates suggest that as much as 3,600 billion tons of CO2 could be stored underground in the United States and Canada combined. For reference, large stationary sources worldwide emit approximately 13 billion tons of CO2 per year. Considering the large storage capacity in the United States, CCS has the potential to be a key technology for achieving domestic greenhouse gas emission reductions. For more information, see the National Carbon Sequestration Database and Geographic Information System (NATCARB),
a geographic information system-based tool developed to provide a view of CCS potential.
Is it safe?
Current scientific and technical knowledge, coupled with ongoing project experience, indicates that well-selected, well-designed, and well-managed geologic sequestration sites can be a safe way to permanently store carbon dioxide (CO2). While CO2 capture and sequestration (CCS) can be conducted safely, EPA recognizes the need to protect against potential risks associated with geologic sequestration, such as leakage of CO2 and changes in subsurface pressures that could impact drinking water, human health, and ecosystems.
What is the federal government doing?
The federal government is conducting a wide range of carbon dioxide (CO2) capture and sequestration-related activities including launching pilot programs, developing safety regulations, sharing technological know-how and addressing other barriers to deployment.
Interagency Task Force on Carbon Capture and Storage
In February 2010, President Obama created the Interagency Task Force on Carbon Capture and Storage to develop a comprehensive and coordinated federal strategy to speed the commercial development and deployment of clean coal technologies. The task force consisted of 14 executive departments and federal agencies, and it was co-chaired by EPA and the U.S. Department of Energy. On August 12, 2010, the task force delivered a series of recommendations to the President on overcoming the barriers to the widespread, cost-effective deployment of CCS within 10 years. The report concludes that CCS can play an important role in domestic greenhouse gas emissions reductions while preserving the option of using abundant domestic fossil energy resources. However, widespread cost-effective deployment of CCS will occur only if the technology is commercially available at economically competitive prices and supportive national policy frameworks are in place. The Task Force's recommendations include specific actions to help overcome remaining barriers and achieve the President's goals.
- Press release
- Executive Summary: Report of the Interagency Task Force of Carbon Capture and Storage (PDF) (10 pp, 91K, About PDF)
- Report of the Interagency Task Force on Carbon Capture and Storage (PDF) (233 pp, 2.7MB, About PDF)
- Fact sheet (PDF) (2 pp, 41K, About PDF)
- Frequently asked questions (3 pp, 37K, About PDF)
- Presidential Memorandum
Other Federal Activities
The federal government is already pursuing a set of capture and sequestration (CCS) initiatives, including research, development, and demonstration of CCS technologies; the development of regulations that address the safety, efficacy, and environmental soundness of injecting and storing carbon dioxide (CO2) underground; and the assessment of the country's geologic capacity to store CO2. For examples of other federal activities, see U.S. Department of Energy and U.S. Geological Survey websites.
What is EPA doing?
EPA's goal is to ensure that geologic sequestration activities are conducted safely and effectively. Through the development of the regulatory framework outlined below EPA is working to ensure that this potential climate change mitigation technology is deployed in a way that is protective of human health and the environment.
Protecting Underground Sources of Drinking Water
EPA has finalized requirements for geologic sequestration, including the development of a new class of wells, Class VI, under the authority of the Safe Drinking Water Act's Underground Injection Control (UIC) Program. These requirements are designed to protect underground sources of drinking water. The Class VI rule builds on existing UIC Program requirements, with extensive tailored requirements that address carbon dioxide (CO2) injection for long-term storage to ensure that wells used for geologic sequestration are appropriately sited, constructed, tested, monitored, funded, and closed. For more information, see Geologic Sequestration of Carbon Dioxide in the Underground Injection Control Program.
Greenhouse Gas Reporting
EPA has also finalized greenhouse gas reporting mechanisms under authority of the Clean Air Act for suppliers of carbon dioxide (CO2) (including CO2 capture), underground injection and geologic sequestration of CO2. This information will enable EPA to monitor the growth and effectiveness of CO2 capture and sequestration (CCS) as a greenhouse gas mitigation technology over time and to evaluate relevant policy options. This rule is complementary to and builds on EPA's Underground Injection Control requirements. For more information, see Subpart PP, Subpart RR, and Subpart UU of the Greenhouse Gas Reporting Program.
Applicability under Hazardous Waste Laws
EPA is working on a regulation that would clarify how carbon dioxide streams injected for geologic sequestration would be classified under the Resource Conservation and Recovery Act (RCRA) hazardous waste requirements. More information on RCRA Hazardous Waste Systems: Carbon Dioxide (CO2) Streams Being Sequestered.
Examining Risks to Human Health and the Environment
In addition, EPA continues to examine the potential risks of geologic sequestration. The Vulnerability Evaluation Framework (VEF) provides policy-makers, stakeholders, industry, and the public with a transparent framework to evaluate vulnerabilities associated with geologic sequestration sites. The VEF can be used to identify areas that require in-depth evaluation for project design, site-specific risk assessment, monitoring, and management. More information on the Vulnerability Evaluation Framework (PDF, 85 pp., 2.1MB, About PDF)
Vulnerability Evaluation Framework for Geological Sequestration of Carbon Dioxide.
Source: EPA (2008)