Grantee Research Project Results
Final Report: Natural Remediation of Contaminated Soil and Ground Water by Barometric Pumping
EPA Grant Number: R826162Title: Natural Remediation of Contaminated Soil and Ground Water by Barometric Pumping
Investigators: Smith, James A.
Institution: University of Virginia
EPA Project Officer: Aja, Hayley
Project Period: January 1, 1998 through December 31, 2001 (Extended to August 31, 2002)
Project Amount: $360,027
RFA: Exploratory Research - Environmental Engineering (1997) RFA Text | Recipients Lists
Research Category: Safer Chemicals , Land and Waste Management
Objective:
The primary objective is to develop and test a vertical flux chamber (VFC) to measure the flux of volatile organic vapors from the unsaturated zone to the atmosphere. The flux chamber must be relatively simple to use and work under diffusion-dominated transport conditions and advection-dominated transport conditions. The flux chamber can be used to monitor natural attenuation of pollutants in shallow ground water and the unsaturated zone.
Summary/Accomplishments (Outputs/Outcomes):
We have designed and tested a VFC that can measure the flux of organic vapors from the unsaturated zone to the atmosphere under natural conditions. The VFC has a unique recirculating air design (through adsorbent traps) and a flexible membrane so that it can accurately measure vapor fluxes under diffusion-dominated transport conditions and under different combinations of diffusive and advective transport (e.g., barometric pumping). The VFC was evaluated in both the laboratory and at a trichloroethene-contaminated field (Picatinny Arsenal, New Jersey) and performed well. Measured organic-vapor fluxes closely matched fluxes predicted using a calibrated airflow and organic-vapor-transport model and extensive subsurface data. Although other flux chambers have been proposed for use in the past, this is the first flux chamber that has been rigorously tested in the field and laboratory under both diffusive and advective flux conditions. Furthermore, its recirculating airflow design coupled with its flexible membrane is unique and effective at accurately and precisely quantifying organic vapor fluxes from the subsurface. This VFC will be well suited for studies of the monitored natural remediation of shallow ground water and the unsaturated zone at contaminated field sites. It may also be used to non-invasively map shallow ground water contamination. The VFC is simple to operate and does not require any subsurface excavation or data collection. The adsorbent traps can be analyzed by standard thermal desorption methods at many commercial laboratories. Each VFC measurement typically requires 2-10 hours, depending on the magnitude of the organic-vapor flux.
Journal Articles on this Report : 5 Displayed | Download in RIS Format
| Other project views: | All 21 publications | 6 publications in selected types | All 5 journal articles |
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Bartelt-Hunt SL, Smith JA. Measurement of effective air diffusion coefficients for trichloroethene in undisturbed soil cores. Journal of Contaminant Hydrology 2002;56(3-4):193-208. |
R826162 (2000) R826162 (Final) |
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Choi J-W, Tillman Jr. FD, Smith JA. Relative importance of gas-phase diffusive and advective trichloroethene (TCE) fluxes in the unsaturated zone under natural conditions. Environmental Science & Technology 2002;36(14):3157-3164. |
R826162 (2000) R826162 (Final) |
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Olson MS, Tillman Jr. FD, Choi J-W, Smith JA. Comparison of three techniques to measure unsaturated-zone air permeability at Picatinny Arsenal, NJ. Journal of Contaminant Hydrology 2001;53(1-2):1-19. |
R826162 (2000) R826162 (Final) |
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Tillman Jr. FD, Choi J-W, Smith JA. A comparison of direct measurement and model simulation of total flux of volatile organic compounds from the subsurface to the atmosphere under natural field conditions. Water Resources Research 2003;39(10):1284, doi:10.1029/2003WR002098. |
R826162 (Final) |
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Tillman Jr. FD, Smith JA. Design and laboratory testing of a chamber device to measure total flux of volatile organic compounds from the unsaturated zone under natural conditions. Journal of Contaminant Hydrology 2004;75(1-2):71-90. |
R826162 (Final) |
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Supplemental Keywords:
trichloroethene, natural attenuation, natural remediation, groundwater, chemical transport, restoration, cleanup, innovative technology, environmental chemistry, engineering, hydrology, measurement methods, EPA Region 2, northeast,, Scientific Discipline, Water, Waste, Toxics, Remediation, Environmental Chemistry, 33/50, Contaminated Sediments, Groundwater remediation, VOCs, Hydrology, Environmental Engineering, contaminant transport, contaminated sediment, natural attenuation, barometric pumping, benzene, Tetrachloroethylene, chemical contaminants, soil sediment, groundwater plumes, carbon tetrachloride, verticle flux chamber, chemical transportProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.