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Troubled Water: Professor Heads Cleanup Project on D.C.-area River High levels of ozone in the atmosphere, a result of pollutants released from automobiles and industry, became a major concern of environmental researchers in the 1970s and 1980s. It was research into the key processes related to ozone pollution that led Danny Reible, then a Ph.D. student in chemical engineering at the California Institute of Technology, to focus his attention on the behavior of pollution in the environment. “When I was at Cal Tech, there was a great deal of interest in the fate and transport of chemicals in the atmosphere,” he said. “I became interested in what happens in other media—soils and sediments.” Today, Reible is director of LSU’s Hazardous Substance Research Center/South & Southwest (HSRC/S&SW). One of five U.S. Environmental Protection Agency (EPA)-funded Hazardous Substance Research Centers in the nation, the HSRC/S&SW at LSU provides basic and applied research, technology transfer, and community outreach that address hazardous substance problems in communities within EPA regions four and six, which cover 12 southern and southwestern states in the U.S. The center is a consortium consisting of LSU, as the lead institution, the Georgia Institute of Technology, Rice University, and Texas A&M University. Each of the five HSRCs has a different research focus. HRSC/S&SW's focus is contaminated sediments. The Anacostia River
Currently, Reible and the HSRC/S&SW are leading a federally funded project to assist in cleaning up the Anacostia River. Known as “The Forgotten River,” the Anacostia, which flows from Maryland to the District of Columbia and into the Potomac, is one of the nation’s 10 most endangered rivers. The tidal river suffers from overall poor water quality caused by large amounts of pollutants, including sediment, excess nutrients, toxics, trash, debris, and a high volume of storm water runoff. The pollution results in chronically low dissolved-oxygen levels that threaten aquatic life and high bacterial levels that make recreational water activities, like swimming, unsafe.
Innovation from LSU
On the Anacostia, Reible and the HSRC/S&SW are demonstrating “active capping,” a process through which contaminants are covered with layers of materials that can degrade or control sediment-bound contaminants. Caps made from sand are often used to reduce the release of contaminants from sediments by physically separating contaminants from organisms and the water column. For the Anacostia demonstration, the research team will cover contaminants with layers of alternative materials that offer treatment and/or sequestration of contaminants beyond simple sand. “Innovative cap approaches may slow contaminant or water migration through the cap or encourage microbial or other degradative processes,” said Reible. “On the Anacostia, specific capping technologies developed at the HSRC and elsewhere were evaluated for inclusion in the demonstration, and those that were most appropriate have been selected and are undergoing final design.” The four-year project is considered a small-scale demonstration, covering just a few acres of the river. “It won’t result in any riverwide water-quality improvement, but in the end, we should have a very clear understanding of what works and what doesn’t, and how to implement what works,” Reible said. “Even then, the actual clean-up will still be eight to ten years away. Some of the problems that caused the contamination still exist. During storms, runoff and overflow of Washington, D.C.’s sewers continue to contaminate the river,” he said. How bad is it?
According to the Anacostia Watershed Toxics Alliance (AWTA), a group formed in 1999 to address the toxic contamination of the river, the Anacostia was proclaimed the nation’s most polluted river in 1997 by America Rivers Conservation Organization and was designated one of only three of the region’s “Areas of Concern” by the Chesapeake Bay Program due to risk to aquatic life. A fish consumption ban was imposed by the District of Columbia due to PCB and pesticide contamination of fish, and cancerous liver tumors were found in more than three fourths of the bullhead fish sampled. Ninety percent of the original wetlands in the area have been lost. The Cost of Cleanup The presence of contaminated sediments in waterways has emerged over the past several years as the leading consumer of the nation’s investment in environmental cleanup.The largest fraction of this cost is incurred in the dredging and disposal of sediment.The new capping technologies that will result from the HSRC’s project may change that.
“Properly implemented, active–capping technology could significantly improve the effectiveness and public acceptance of capping as a remedial approach,” Reible said. It was through the efforts of the AWTA, with the support of the EPA’s Technology Development Forum, that Reible and the HSRC/S&SW became involved with the Anacostia cleanup. In 1999, the AWTA were looking for faster and cheaper ways to clean up the river. In December 2001, the HSRC/S&SW was awarded $2.25 million for the capping project under the District of Columbia Appropriations Act. The House Report presented to Congress at the time states that the HSRC’s “active cap” technologies will “advance ongoing federal restoration of the river, . . . enhance regulatory acceptance of the technology, . . . [and] dramatically slash the cost and duration of cleanups across the country.” In 2002, the center was awarded another $1 million for the project. An additional $1 million for 2003–2004 and 2004–2005 is expected to support the monitoring of the demonstration. Closer to Home
While the Mississippi River in Louisiana—especially given the concentration of industry along the river—may seem an obvious candidate for similar restoration, Reible said it is not. “The Mississippi River sediments are typically fast-moving sands that do not tend to accumulate contaminants,” he said. Also, industries that would be potential polluters along the Mississippi are relatively young and have been following stricter, more recent contaminant disposal guidelines than did many of older industrial sources that have given rise to some of the most contaminated sediment areas in the U.S. “Many of the most contaminated waterways in the country are in the northeast and midwest, around the Great Lakes, where turn-of-the-century industries and water treatment approaches have left their legacy,” Reible said. Waterways in Louisiana that may benefit from new capping technologies include bayous in the southeastern part of the state and the Calcasieu Estuary in the southwest, approximately 15 miles north of the Gulf of Mexico. Regulators, community groups, and industry are currently exploring options for cleaning up contaminated sediments at Calcasieu. The HSRC/S&SW may be able to help. “We are currently initiating studies with one company to help evaluate remedial alternatives for a lagoon in the estuary,” Reible said. “The goal will be to ensure that the best scientific information is available to select the best way of remediating the sediments.” Contact Marybeth Pinsonneault |
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