EPA Proposes Easing CO₂ Controls

Carbon dioxide injected underground would not be treated as a hazardous waste under an EPA proposal issued Aug. 4. The proposal would aid CO₂ capture and sequestration projects currently being tried as a means to reduce CO₂ air emissions from coal-fired power plants, chemical companies, and other large industrial operations. EPA says in its proposal that its intention is to reduce barriers for use of CO₂ reduction technologies because CO₂ is a primary contributor to climate change. However, drinking water suppliers have voiced concerns that underground injection of CO₂ will increase the likelihood of the gas coming into contact with drinking water. Although not a poison itself, CO₂ can make water acidic and corrosive, and it has the potential to leach natural contaminants from soil and rocks when held in a supercritical state within Earth’s geologic reserves (C&EN, Sept. 21, 2009, page 32). EPA’s proposal, the agency notes, is one of many to encourage carbon capture and sequestration, which will allow the nation to continue burning coal, and to expand locations where CO₂ can be injected.