From Tech Trends August 1994

Unique Multi-Vendor Bioremediation Demonstration Begins

By James B. Harrington, New York State Department of Environmental Conservation

Three pilot-scale bioremediation studies are being conducted concurrently at the same site, the Sweden 3 - Chapman inactive hazardous waste site in the Town of Sweden, Monroe County, New York, as part of a Multi-Vendor Treatability Demonstration of Bioremediation Technologies (MVTD). Having three vendors working concurrently on the same site, each using a different biotechnology, is quite unique. The purpose of the project is to demonstrate the application of innovative technologies utilizing bioremediation for treatment of soils contaminated with volatile organic compounds (VOCs). The 12-month pilot-scale demonstration is being jointly sponsored by the New York State Department of Environmental Conservation (NYSDEC), the New York State Center for Hazardous Waste Management (NYS Center) and the U.S. Environmental Protection Agency's Superfund Innovative Technology Evaluation (SITE) Program.

The objectives of the MVTD demonstration are to: (1) demonstrate that use of naturally occurring microorganisms can be effective in remediating a hazardous waste site in New York State; (2) generate field data to allow the simultaneous comparison of different biological processes; (3) permit an evaluation of in-situ and ex-situ approaches; and (4) evaluate the performance of each biological approach in meeting the clean up goals established for the site.

The three vendors and the technology that each will demonstrate are: (1) SBP Technologies, Inc. and Environmental Laboratories, Inc. UVB (Vacuum- Vaporized Well) system; (2) the R.E. Wright Associates, Inc. In-Situ Field Bioremediation Treatment System; and (3) the ENSR Consulting and Engineering and Larson Engineers Ex-Situ Biovault. The first process consists of a specially adapted ground water well, a negative pressure stripping reactor, an in-situ bioreactor and an above-ground vapor-phase bioreactor. This process focuses on removing volatile contaminants out of the soil above the water table as well as volatile contaminants in the ground water. The contaminants are then treated biologically. The second process utilizes bioventing technology where injection and extraction wells will allow the vendor to regulate oxygen and nutrient levels to stimulate the native bacteria in the soil into biodegrading the contaminants of concern. The third process is based upon the construction of two identical biovaults. Contaminated soils are placed in each biovault where nutrient, moisture and oxygen levels can be controlled. The first biovault is operated under aerobic conditions. The second biovault is operated back and forth between aerobic and anaerobic conditions.

These MVTD pilot-scale demonstrations will not interfere with on-going remediation at the site, where approximately 2,500 drums of hazardous waste and grossly contaminated soil have already been removed. The Record of Decision, signed in March 1994, specified excavation of contaminated soil with on-site treatment via Low Temperature Thermal Desorption; limited ground water remediation is also specified. If the MVTD project is successful, these technologies will be used to remediate the remaining contamination at the site.

The three vendors for the MVTD were chosen through a competitive process. Thirteen technical proposals were submitted in response to a formal Request for Proposal. After a review of those proposals, nine technology vendors were invited to submit bids. The three vendors selected began field work in July 1994.

The NYS Center coordinated the development of the protocol that was the centerpiece of the Requests for Proposals and will be on-site to document vendor progress and provide sample collection assistance. The SITE program will provide sample collection and analytical services, sampling protocol development and project reports. The NYSDEC developed the project and is leading it, providing management and funding for the treatment vendors and construction support services necessary to implement the study.

For more information, call Jim Harrington at NYSDEC at 518-485-8792.