Air Force Plant 6 Remediation Assistance Program

Project Number: 2503-A10AF
Project Chief: John Clarke
Cooperators: U.S. Air Force, Aeronautical Systems Center
Period of Project: 1995 to present

Introduction

United States Air Force (USAF), Aeronautical System Center (ASC) is conducting environmental remediation activities at Air Force Plant 6 (AFP6) in Marietta, Georgia. These activities include addressing complex ground-water contamination, primarily the result of long–term manufacturing processes. Significant contamination of ground water by Dense Non-Aqueous Phase Liquids (DNAPL), that were employed as degreasing solvents, and metals above regulatory limits exist on and adjacent to USAF property. Remediation is extraordinarily difficult because of numerous historic point and non-point contamination sources, and most importantly by an extremely complex ground-water flow system, characterized by non-porous media flow in fractured and weathered metamorphic and igneous bedrock.

To support and enhance environmental remediation activities at AFP6, the U.S. Geological Survey (USGS) is conducting hydrogeologic investigations that characterize ground-water flow and contaminant movement in fractured crystalline rock. This includes providing technical guidance to ASC and assisting and advising ASC contractors, as well as conducting specific characterization and delineation efforts that directly support remediation.

Plans for FY-2008 (October 1, 2007-September 30, 2008)

1. Bedrock remediation monitoring and database activities. This information is being used to assess effectiveness of remediation strategies.
1. Collect and analyze water samples for VOCs and degradation by-products on a semi-annual basis from a network of wells (includes analyses for natural attenuation parameters).
2. Assess changes in contaminant discharge to Rottenwood Creek by deploying diffusion samplers and analyzing for TCE and degradation by-products.
3. Operate 8-well continuous water-level monitoring network.
4. Ensure that various well, geophysical, aquifer test, and water quality data collected during the project are properly archived into USGS databases.
2. Bedrock remediation support in the B4 area in the vicinity of offsite bedrock monitoring well MWOS2R, in which high levels of TCE (greater than 2,500 micrograms per liter) have been detected and are increasing. This information will be used to guide remediation strategy in fractured crystalline bedrock.
   1. Conduct tracer studies to assess ground-water flowpaths and rates of flow.
   2. Evaluate surficial and subsurface geology by mapping and evaluating existing borehole geophysical data.
3. Continue to provide ASC technical support, including evaluation of contractor performance, and representation to GaEPD
4. Prepare and publish reports summarizing a variety of topics that support remedial activities, including water-quality and geophysical data tabulations, water-quality trends, hydrogeologic characterization in the B4 & offsite area, aquifer-test results, and packer-test results. This information is being used to guide remediation strategies and assess their effectiveness.

Links to websites of interest

• USGS Toxic Hydrology Program:
• USGS National Research Program-Transport Phenomena in Fractured Rock

USGS Research Sites-contamination in Fractured Rock Aquifers
• Mirror Lake Research Site, New Hampshire
• Naval Air Warfare Center (NAWC) Research Site, West Trenton, NJ

• Air Force Center for Engineering and the Environment
• Air Force Aeronautical Systems Center - Engineering Directorate (includes AFP6 publications)

Bibliography

Gonthier, G. J, 2007a, Estimates of barometric efficiency using a graphical method on nearly continuous data: in 2007 GWRC Proceedings, CD-ROM, also online at http://ga.water.usgs.gov/publications/gwrc07/pdf/Gonthier_GWRC07.pdf

Gonthier, G. J, 2007b, A Graphical Method for Estimation of Barometric Efficiency from Continuous Data-Concepts and Application to a Site in the Piedmont, Air Force Plant 6, Marietta, Georgia: U.S. Geological Survey Scientific Investigations Report 2007-5111; 29 p. Online only at: http://pubs.usgs.gov/sir/2007/5111/

Gonthier, G. J, and Mayer, G.C., 2003, Slug-test results from a well completed in fractured crystalline rock, U.S. Air Force Plant 6, Marietta, Georgia: in 2003 GWRC Proceedings, CD-ROM, also online at http://ga.water.usgs.gov/pubs/other/gwrc2003/pdf/Gonthier-GWRC2003.pdf

Gonthier, G.J., and Waddell, J.P., 2001, Trichloroethene presence in Rottenwood Creek near Air Force Plant 6, Marietta, Georgia, summer 2000, in Hatcher, K.J., ed., Proceedings of the 2001 Georgia Water Resources Conference, Institute of Ecology, University of Georgia, Athens, GA, p. 586-589. also on line at http://ga.water.usgs.gov/pubs/other/gwrc2001/pdf/gwrc01.pdf

Stewart, L.M., 2000, Laboratory analytical results for ground-water sampling at Southern Polytechnic State University, Marietta, Georgia, 1997, U.S. Geological Survey Open-File Report 00-277, 28 p., also online at http://pubs.usgs.gov/of/2000/ofr00-277/

Waddell, J.P., and Mayer, G.C., 2003, Effects of Fenton's reagent and potassium permangante applications on indigenous subsurface microbiota-A literature review: in 2003 GWRC Proceedings, CD-ROM, also online at http://ga.water.usgs.gov/pubs/other/gwrc2003/pdf/Waddell-GWRC2003.pdf