Technology Merit: Remediation

Share

Groundwater & Environmental Services, Inc. (GES; Neptune, NJ; www.gesonline.com) for the successful deployment of its patented HypeAir-EX in situ chemical oxidation technology in the aggressive remediation of coal tar at a former manufactured gas plant (MGP) site in Iowa. GES operated the system for two months, at a cost under $300,000, to destroy volatile and semi-volatile organic compounds in coal tar, soil, and groundwater. This innovative approach, using ozone and hydrogen peroxide injection, was much cheaper, more effective, and less disruptive than more commonly used options such as excavation and thermal treatment, according to GES. The technical approach involved the injection of ozone, at a rate of 75 pounds per day, with periodic injection of hydrogen peroxide to maximize hydroxyl radical formation and contaminant destruction. The project is the latest aggressive remediation success by GES's Max-Ox Group, GES' remediation services division. The Max-Ox Group has performed more than 300 chemical oxidation projects across the US, and has teamed with other environmental consulting firms to provide cost-effective remediation solutions, many contracted on a pay-for-performance basis.

RMT, Inc. (Madison, WI; www.rmtinc.com) for the development of a new technology to address the ongoing human health and environmental risks from sediment contaminated by MGPs-a problem that has been misunderstood and difficult to remedy in scores of water bodies. RMT diagnosed the mechanisms that cause coal tar buried in sediments to migrate into overlying water. Understanding gas bubble migration from biodegrading organic material, which is typical in many sediments, was a key to developing a solution to stop coal tar exposure. RMT's NAPL Trapping Cap (patent pending) is designed to permanently control tar migration from sediment by redirecting migrating tar to a controlled accumulation area, where the tar is trapped while the gas is vented to the atmosphere. This system eliminates exposure to human and ecological receptors of tar; vastly reduces human health risks; reduces costs by creating a targeted remediation area; and alleviates short- and long-term risk via permanent migration control. RMT designed and built a full-scale application of the NAPL Trapping Cap remedy-the first of its kind, according to the company-on the Penobscot River in Maine, a site that posed extreme engineering challenges.

EOS Remediation LLC (Raleigh, NC; www.eosremediation.com) for the successful commercialization in 2009 of EAS, a sulfate-enhanced technology for in situ remediation of contaminated groundwater. The conventional wisdom for remediation of aquifers contaminated with petroleum hydrocarbons (PHCs) is to add oxygen. A recent British Petroleum/EPA study, however, has concluded that most hydrocarbon plumes are anaerobic and depleted of sulfate, and other studies have drawn comparable conclusions. EAS is an anaerobic degradation process that facilitates natural attenuation of PHCs in the subsurface. This process occurs when terminal electron acceptor compounds such as nitrate, sulfate, and iron react to reduce PHC concentrations. The EAS process stimulates biodegradation by providing a soluble, readily available electron acceptor. In the presence of elevated sulfate, anaerobic groundwater bacteria use the PHCs for carbon and energy while mineralizing the hydrocarbons to carbon dioxide and water. According to EOS, EAS is a "green technology" that accelerates site cleanup and reduces carbon footprint when compared to conventional remediation.

AMEC Earth & Environmental, Inc. (Plymouth Meeting, PA; www.amec.com) for two innovative technology demonstration projects for the Air Force that promise to save time and money while improving the remediation of contaminated sites. One of the projects is evaluating the use of Bio-Trap microbial samplers at Air Force Plant 4 in Texas, where groundwater is contaminated with trichloroethylene (TCE) and other chlorinated solvents. The samplers, which capture naturally present bacteria in order to evaluate their biodegradation potential, are being evaluated on site for their ability to determine the best bioremediation techniques. The other project is focused primarily on source-zone remediation and involves the testing of stabilized nano-scale iron for treatment of chlorinated solvents in groundwater. The technology being tested is an environmentally friendly cellulose stabilizer coating on the iron nano-particles that is expected to prevent agglomeration, thereby improving the delivery of the nano-particles to the aquifer and maintaining their high reactivity with the contaminants. If successful, cellulose-stabilized nano-scale iron will significantly accelerate the cleanup of groundwater and may reduce life-cycle treatment costs by as much as 90%.