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Carbon sequestration concerns raised
Carbon sequestration ― the plan to reduce greenhouse gases by storing them underground ― was back in the news this month: AWWA's concerns were reported in environmental newsletters after an Oct. 1 webcast. The US Government Accountability Office released recommendations on needed federal actions. A congressman warned that the hastily written bail-out bill complicates life for USEPA on the subject. A number of concerns were raised during AWWA's webcast ― "Carbon Sequestration Rule: How Will It Affect Our Water Supply?" ― regarding drinking water protection under USEPA's proposed rule. A major concern raised in the webcast was the potential contamination of underground sources of drinking water (USDWs) if the carbon dioxide leaks from the confining zone. If this occurs, the pH changes in the aquifer could cause the dissolution of heavy metals and the leaching of inorganic compounds out of the geologic formation and into the aquifer. Another possibility is that the pressure front associated with the carbon dioxide plume will cause the displacement of brine aquifers into UDSWs, resulting in elevated TDS concentrations. In either case, the result would be a significant increase in treatment costs for the drinking water utility. In severe cases, it could result such a high level of contamination that the utility would have to find an alternative drinking water source. Another concern raised in the webcast related to Safe Drinking Water Act definition of a USDW. Currently, a USDW is any aquifer with a TDS concentration less than 10,000 mg/L. Given that several water utilities are currently using drinking water sources with TDS concentrations that are higher than the current definition, AWWA would like to see the definition of a USDW expanded, says Cynthia Lane, AWWA regulatory specialist for environmental affairs. Several other associations have voiced similar concerns, she said, including the American Public Power Association and the Environmental Defense Fund. She noted that only Congress would be able to modify the definition of a USDW, as this is outside of USEPA’s regulatory authority. AWWA is planning to submit comments to USEPA on the proposed rule that would strengthen the protection of USDWs. "We will also be submitting joint comments with the American Public Power Association on several topics, including the expansion of the definition of a USDW, the provision of special protective measures for sole-source aquifers and the need for more research by USEPA on the potential impacts of carbon sequestration on drinking water sources," Lane said. The GAO report ― "Climate Change: Federal Actions Will Greatly Affect the Viability of Carbon Capture and Storage As a Key Mitigation Option" ― concluded that the key barriers to carbon capture and storage (CCS) deployment are, one, underdeveloped and costly technology, and, two, regulatory and legal uncertainties for carbon dioxide capture, injection and storage. Long-term liability for injected carbon dioxide is a particular concern, the report said. The question is who will pay if carbon dioxide leaks into a drinking water aquifer or if carbon dioxide injection forces brackish water into a freshwater aquifer? GAO recommended that an interagency CCS task force be established. Although the Department of Energy has a coordinating task force, it focuses only on technology, according to GAO, and not on resolving legal and jurisdictional issues such as are inherent in CCS. GAO also was of the opinion that too little attention was focused on retrofitting existing plants that generate carbon dioxide, instead of addressing new construction. Complicating matters is the "bailout bill" (HR 1424), which according to a letter by House Energy and Commerce Committee Chairman John Dingell, D-Mich., is written in such as way as to give the Secretary of the Treasury the responsibility of consulting with the USEPA Administrator on "regulations for determining adequate security measures for" carbon sequestration. The bailout package includes a tax credit of $20 per ton of carbon dioxide for facilities that capture and dispose of, or use as a tertiary injectant, 75 million metric tones of carbon dioxide. Noting that the section obligates the Secretary of the Treasury to establish these environmental regulations, Dingell expressed concern that the secretary "could issue requirements for carbon dioxide sequestration that conflict with EPA's regulation of this process." Comments on USEPA's CCS proposal under the Safe Drinking Water Act are due Nov. 24. (Search http://www.regulations.gov/search/index.jsp for "EPA-HQ-OW-2008-0390.") The final rule is expected in late 2010 or early 2011. Additional AWWA Resources:
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