Jump to main content.


Frequent Questions: Hazardous Waste Management System: Conditional Exclusion for Carbon Dioxide (CO2) Streams in Geologic Sequestration Activities

Addtional questions regarding the Geologic Sequestration Class VI Wells


Is CO2 hazardous? Why is EPA excluding CO2 captured from industrial sources from the hazardous waste regulations?

Carbon dioxide (CO2) is not normally considered a waste under the Resource Conservation and Recovery Act (RCRA). However, CO2 that is captured (referred to as "CO2 streams") from emission sources like power plants and large industrial operations and injected deep underground in Underground Injection Control (UIC) Class VI wells for the sole purpose of long-term isolation from the atmosphere is considered by EPA to be a waste. EPA sought to clarify whether or not the RCRA hazardous waste regulations apply to captured CO2 streams, particularly if the captured CO2 streams contain hazardous constituents. EPA’s rule excludes the captured CO2 streams (that might otherwise be defined as hazardous) from EPA’s hazardous waste regulations provided the streams are captured from emission sources, injected underground via UIC Class VI injection wells approved for purposes of geologic sequestration, and meet certain other conditions. EPA concluded that the management of CO2 streams under the specified conditions does not present a substantial risk to human health or the environment and will encourage the deployment of CCS technologies in a safe and environmentally protective manner while also ensuring protection of underground sources of drinking water.

EPA is taking this action to reduce regulatory uncertainty, consistent with one of the recommendations made by President Obama’s Interagency Task Force on Carbon Capture and Storage (CCS) in August 2010.

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 carbon dioxide capture and sequestration (CCS). For more information on geologic sequestration, go to Carbon Dioxide Capture and Sequestration website.

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 geosequestration 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 rule’s 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.

To whom does this conditional exclusion apply?

The conditional exclusion applies to generators, transporters, and owners or operators of treatment, storage, and disposal facilities engaged in the management of carbon dioxide 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 carbon dioxide 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 is the basis for this conditional exclusion from the RCRA hazardous waste requirements?

EPA evaluated existing regulations that would apply to the capture and injection of CO2 streams, such as applicable transportation and related pipeline requirements, and requirements for Class VI Underground Injection Control (UIC) wells. With respect to the injection process, the UIC Class VI rule builds on existing UIC Program requirements, with extensive tailored requirements that are designed to address CO2 stream 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, together with certain other existing federal regulations (e.g., Department of Transportation requirements) support EPA’s finding that CO2 streams that might otherwise be defined as hazardous waste do not present a substantial risk to human health or the environment when managed under the conditions of the final rule, and therefore additional regulation pursuant to RCRA’s hazardous waste regulations is unnecessary.

What does this rule mean for CCS facilities that use the CO2 for Enhanced Oil Recovery/Class II wells?

The final rule is a conditional exclusion from the RCRA definition of hazardous waste for CO2 injected into UIC Class VI wells. This exclusion is voluntary, and need not be employed where no hazardous waste is involved, but is intended to provide an option if there is a concern that a CO2 stream is a hazardous waste. Because the scope of the final rule was limited to CO2 injected into UIC Class VI wells for purposes of GS, this rule does not affect CO2 injected into UIC Class II/EOR wells. EPA believes that, should CO2 be used for its intended purpose as it is injected into UIC Class II wells for the purpose of EOR, such an injection process would not generally be a waste management activity. In essence, this means the option for a conditional exclusion should be unnecessary, as such CO2 would not be a RCRA-regulated [solid] waste in the first instance.

What other EPA rulemakings are related to geologic sequestration (GS)?

In an effort to support the future development and deployment of geologic sequestration (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 help provide a clear pathway for widespread deployment.

In addition to this rule, the Federal Requirements under the Underground Injection Control (UIC) Program for Carbon Dioxide (CO2) Geologic Sequestration (GS) Wells directly addresses GS activities.

Two other components of a supportive national policy framework for CCS include EPA's proposed Carbon Pollution Standards for new power plants, which will promote implementation and further development of CCS technologies, and requirements for greenhouse gas reporting.

 

Top of Page


Local Navigation




Jump to main content.