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Frequent Questions about Carbon Dioxide (CO2) Streams Being Sequestered
- Is CO2 hazardous? Why is EPA excluding potentially hazardous CO2 from hazardous waste regulations?
- What is geologic sequestration?
- Does EPA consider CO2 streams captured at power plants and industrial facilities destined for a UIC Class VI well for the purposes of geologic sequestration a hazardous waste?
- Who does this exemption apply to?
- What other recent EPA rulemakings are related to geologic sequestration?
- How do UIC Class VI wells address the unique risks associated with geologic sequestration?
- Background
Is CO2 hazardous? Why is EPA excluding potentially hazardous CO2 from hazardous waste regulations?
Carbon dioxide (CO2) is not normally considered a waste under RCRA. However, CO2 streams that are captured at stationary sources like power plants and large industrial operations and injected deep underground for the purpose of long-term isolation from the atmosphere are considered by EPA to be wastes. If the captured CO2 stream contains hazardous constituents, such that the CO2 stream might meet the definition of hazardous waste, EPA proposes to conditionally exclude that CO2 stream from hazardous waste regulations, provided that the conditions in the proposal are met. The proposed conditions for this exclusion include compliance with applicable transportation and related pipeline requirements, injection into Class VI Underground Injection Control (UIC) wells for the purposes of geologic sequestration (GS), and the prohibition on mixing hazardous waste with the CO2 stream.
The Agency has concluded that the Safe Drinking Water Act’s UIC Class VI well regulations and existing federal regulations fully address potential risks of geologically sequestered CO2 streams.
This proposal is consistent with recommendations made by President Obama’s interagency task force on this topic and helps create a consistent national framework to ensure the safe and effective deployment of technologies that will help position the United States as a leader in the global clean energy race.
What is geologic sequestration?
Geologic sequestration is the long-term containment of CO2 in subsurface geologic formations and is a key component of a set of climate change mitigation technologies known as CO2 capture and sequestration (CCS). For more information on geologic sequestration, visit Geologic Sequestration.
Does EPA consider CO2 streams captured at power plants and industrial facilities destined for a UIC Class VI well for the purposes of geologic sequestration a hazardous waste?
A CO2 stream injected into a permitted UIC Class VI well for purposes of GS is a RCRA solid waste, as it is a “discarded material” as defined in RCRA §1004(27). EPA believes that while there is little information available to conclude that CO2 streams would qualify as a RCRA subtitle C hazardous waste, there is the potential for some CO2 streams to meet the definition of a hazardous waste. EPA concluded that the management of CO2 streams under the proposed conditions does not present a substantial risk to human health or the environment, and will encourage the geologic sequestration of CO2, in a safe and environmentally protective manner.
Who does this exemption apply to?
The proposed exclusion, if finalized, may apply to generators, transporters, and owners or operators of treatment, storage, and disposal facilities engaged in the management of CO2 streams that would otherwise be regulated as hazardous wastes under the RCRA subtitle C hazardous waste regulations as part of geologic sequestration activities. This includes entities in the following industries: operators of CO2 injection wells used for geologic sequestration; and certain industries identified by their North American Industry Classification System (NAICS) code: oil and gas extraction facilities (NAICS 211111); utilities (NAICS 22); transportation (NAICS 48-49); and manufacturing (NAICS 31-33).
What other recent EPA rulemakings are related to geologic sequestration (GS)?
In an effort to support the future development and deployment of GS technologies, EPA has set a goal to provide the regulatory certainty needed to foster industry adoption of GS. The Agency believes that GS is a key climate change mitigation technology; therefore, providing a consistent regulatory approach to GS will reduce barriers to widespread deployment.
EPA recently finalized two important rules that directly address GS activities: Federal Requirements under the Underground Injection Control (UIC) Program for CO2 Geologic Sequestration (GS) Wells; and Subpart RR of the Greenhouse Gas Reporting Program.
How do UIC Class VI wells address the unique risks associated with geologic sequestration?
The proposed conditions for this exclusion include compliance with applicable transportation and related pipeline requirements, injection into Class VI Underground Injection Control (UIC) wells for the purposes of geologic sequestration (GS), and the prohibition on mixing hazardous waste with the CO2stream. The Class VI rule builds on existing UIC Program requirements, with extensive tailored requirements that address CO2 injection for long-term storage to ensure that wells used for geologic sequestration are appropriately sited, constructed, tested, monitored, funded, and closed. The Agency has concluded that the Safe Drinking Water Act’s UIC Class VI well regulations and existing federal regulations fully address potential risks of geologically sequestered CO2 streams.
Background
In an effort to support the future development and deployment of carbon capture and sequestration (CCS) technologies, EPA has set a goal to provide the regulatory certainty needed to foster industry adoption of CCS. CCS technologies have the potential to enable large emitters of CO2, such as coal fired power plants, to significantly reduce greenhouse gas emissions. This technology allows CO2 to be captured at stationary sources like power plants and large industrial operations and injected underground for long-term storage in a process called geologic sequestration (GS).
EPA recently finalized two important rules related to CCS activities. The Underground Injection Control (UIC) Class VI rule, established under authority of the Safe Drinking Water Act, sets requirements to ensure that GS wells are appropriately sited, constructed, tested, monitored, and closed. Subpart RR of the Greenhouse Gas Reporting Program, which was established under authority of the Clean Air Act and builds on UIC requirements, enables EPA to track the amount of CO2 sequestered by these facilities.
The proposed action would complement the final Safe Drinking Water Act rule by clarifying how the injected material would be classified under hazardous waste laws (RCRA).
In August 2010, President Obama’s Interagency Task Force on CCS, co-chaired by the EPA, delivered a series of recommendations to the President on overcoming the barriers to the widespread, cost-effective deployment of CCS within 10 years. The Task Force concluded that this proposal is an important part of the strategy to promote development of CCS technologies.
