Water Resources Research Act Program

Details for Project ID 2006AL48B

Pilot Testing an Innovative Remediation Technology for In-situ Destruction of Chlorinated Organic Contaminants in Alabama Soils and Groundwater Using a New Class of Zero Valent Iron Nanoparticles

Institute: Alabama
Year Established: 2006 Start Date: 2006-03-01 End Date: 2007-02-28
Total Federal Funds: $25,000 Total Non-Federal Funds: $50,005

Principal Investigators: Dongye Zhao

Project Summary: Chlorinated hydrocarbons are well known potent toxins to human health and environment . Although the uses of chlorinated hydrocarbons have now been either banned or highly restricted, the past massive production and applications have left an environmental legacy that large areas of soils and groundwater in Alabama are contaminated with dangerously high concentrations of chlorinated hydrocarbons. In the mid 1990s, one of the most contaminated sites in the United States was discovered in Anniston, Alabama. In 1990 the Environmental Defense Fund Scorecard ranked Calhoun County, where Anniston is located, among the worst 20% of all counties in the United States in terms of an average person's added cancer risk from hazardous waste. The nationally known PCE/TCE site in Alabama is the "Montgomery capital plume" site located right in downtown Montgomery. The contaminated groundwater plume is believed to exist throughout the downtown Montgomery area. Following 17 months of investigation in 1995 of PCE contamination in the capital city, the Alabama Department of Environmental Management concluded that there were a minimum of 6 groundwater plumes contaminated with PCE, benzene, toluene, ethylbenzene, and xylene. On May 11, 2000, the site was proposed to be listed on the National Priorities List. Currently, the City of Montgomery has shut down two contaminated wells, and initiated an $18.6 million clean up action. Unfortunately, there have been no cost-effective and environmentally benign remediation technologies available for remediation of chlorinated soils and groundwater despite tremendous research efforts in the past three decades. To a great extent, current remediation practices rely on excavation and landfill of contaminated soils, which are extremely costly and environmentally disruptive. For cases like the capital plume site, since the site is located in the heavily populated downtown area, engineered processes (e.g., excavation) are highly restricted. Currently, Alabama is home to 12 EPA-designed National Priorities List (NPL) sites and 2 proposed NPL sites. Of all toxins detected at these sites, chlorinated hydrocarbons are among the most wide-spread and most harmful contaminants to our groundwater. Using current technologies, clean up of each of those sites would cost millions of dollars over the next several decades. Consequently, there is an urgent need for developing new cost-effective in-situ technologies for the clean-up of Alabama soils/groundwater contaminated by chlorinated hydrocarbons. This project builds on a highlt successful FY-2003 AWRRI project by the PI, which resulted in a new class of zero-valent iron (ZVI) nanoparticles and a patented remediation technology based on the nanoparticles. The nanoparticles have been judged, by a group at The University of Michigan (Huang et al, 2005), the most suitable nanoparticles for in-situ dechlorination uses. This proposed work is a critical and logical step toward ultimate field application of the promising technology, and will yield critical information on the technical and cost effectiveness and necessary design and operating parameters. Given the known health risks of chlorinated hydrocarbons, the scope and extent of the contamination and the economic burdens, the resulting technology will provide millions of affected people with immediate and tangible health and economic relief. According to recent estimates by the U. S. Environmental Protection Agency, the in-situ injection process can potentially cut down remediation cost by >90% compared to conventional technologies.