18 July 2008
U.S. Environment Agency Seeks To Regulate Carbon Dioxide Storage
Proposal would mandate monitoring, testing CO2 injected deep underground
Washington -- In a move that could help commercialize a fledgling technology for storing the greenhouse gas carbon dioxide (CO2) in deep underground rock formations, the U.S. Environmental Protection Agency (EPA) is proposing technical criteria for well construction, operation and monitoring.
The proposal by the agency’s Office of Ground Water and Drinking Water was issued under the authority of the Safe Drinking Water Act, which protects underground water sources from injection-related activities.
Elements of the proposed rule are based on EPA’s existing underground injection control program, which addresses five categories of wells. The proposed rule would add a sixth category specifically for geologic storage of carbon dioxide 800 meters or more underground.
“This rule paves the way for technologies that would protect public health and help reduce the effects of climate change,” Benjamin Grumbles, EPA’s assistant administrator for water, said during a July 15 briefing.
“With proper site selection and management,” he added, “EPA believes geologic sequestration could play a major role in reducing emissions of CO2 to the atmosphere while protecting our nation’s vital underground water sources.”
REDUCING CARBON DIOXIDE
Carbon dioxide is one of the greenhouse gases whose excessive presence in the atmosphere is warming the planet and driving global climate change. Of the many efforts under way worldwide to reduce greenhouse gas emissions, one whose use is growing is CO2 capture and storage, or carbon (dioxide) sequestration.
In CO2 capture, carbon dioxide is collected from gaseous emissions from fossil-fueled power plants, refineries and other industrial facilities. In CO2 storage, captured carbon dioxide is injected into geologic formations like sandstone or limestone saline aquifers, or old oil and gas fields and coal beds that no longer can be mined.
The end result is a reduction in the total amount of excess CO2 in the atmosphere. (See “Tests on Capturing, Storing Carbon Dioxide Move Forward.”)
In the United States and around the world, engineers have been capturing CO2 from industrial flue streams for 70 years and injecting it underground for 30 years to enhance oil recovery. Injecting CO2 into an oil field reduces oil viscosity, expands its volume and changes its stickiness, all of which help drillers get more out of the ground. But sequestration efforts that combine capture and storage have been occurring only since about 1997.
DEMONSTRATING SEQUESTRATION
A range of capture technologies and demonstration projects are being developed worldwide but none is yet commercially available. About 35 million tons of CO2 are stored in the United States, according to the U.S. Department of Energy (DOE), mainly for enhanced oil recovery. More recently, after 10 years of research, DOE and EPA are funding the first large-scale U.S. demonstration projects.
Three projects in the United States and Canada will conduct large-volume tests for storing 1 million or more tons of CO2 in deep saline aquifers -- porous rock formations deep in the earth whose pores contain salty water and can be filled with CO2.
Twenty-seven states and the Canadian provinces of Alberta, Saskatchewan and Manitoba plan to participate in the projects. They will demonstrate the entire CO2 injection process at large volumes to determine the capacity of different geologic settings to store CO2 permanently.
All are part of the Regional Carbon Sequestration Partnership, which is working to determine the best technologies, regulations and infrastructure needs for CO2 capture and storage in different regions of the United States and Canada.
GOING COMMERCIAL
For the next 120 days, the EPA will accept comments on the proposed rule from policymakers, experts and the public. After considering those comments, the agency will adjust the proposal as it deems appropriate. The EPA expects to issue a final rule in late 2010 or early 2011. Currently, anyone who has stored carbon dioxide underground to test the process has done so with limited experimental permits from the EPA.
The new regulations are intended to offer “consistent national standards” and safeguards, Grumbles said, while allowing for individual state regulations to account for site-specific geologic settings and circumstances.
“A key feature of this proposed rule is extensive monitoring throughout the entire process,” he added, “so that we and state regulators can prevent as quickly as possible any type of migration, leakage or potential problem. With the experiences we’ve had on the pilot project and throughout the world on geosequestration, we have not seen problems. However, we think it’s important to be proactive and include extensive monitoring.”
The July proposed rule would address only one aspect of carbon sequestration. Grumbles said EPA plans to work with its Office of Air and Radiation on proposed rules for capturing carbon dioxide at industrial or energy-related facilities, and with agencies such as the Department of Transportation on issues involving the transport of carbon dioxide to storage sites.
The full text of the proposed carbon sequestration rule and a related fact sheet are available on the EPA Web site.
