Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-25T18:00:40.863Z Has data issue: false hasContentIssue false
  • English
  • Français

Impact of Atmospheric Pressure Fluctuations on Vadose-zone Contaminant Plumes

Published online by Cambridge University Press:  11 February 2011

Wayne C. Downs
Wayne C. Downs*
Affiliation:
Department of Civil Engineering, Brigham Young University Provo, UT Chang H. Oh, Todd Housley, and Jeff Sondup Idaho National Engineering and Environmental Laboratory, Idaho Falls, ID
Get access

Abstract

Field and laboratory studies have been underway at the INEEL and BYU to investigate the effect of atmospheric pressure fluctuations on the migration of contaminant plumes.

In the field, two vadose-zone piezometer nests were instrumented to measure soil-pressures and carbon tetrachloride concentrations at depths of roughly 78-ft, 112-ft., and 150-ft., below ground surface in wells 25-ft. apart. At land surface, a manifold was constructed to systematically rotate from port to port at 15-minute increments of time. Contaminant concentrations were measured at each rotation, and soil pressures were measured at all ports at 15-minute increments. Atmospheric pressures were also recorded. Results showed that atmospheric pressure changes propagated downward lagged in time and dampened in amplitude. Carbon tetrachloride concentrations were observed to decrease with pressure increases at each port, suggesting that pressure increases pushed the plume downward. Increases in concentration were observed with decreases in pressure. Concentrations were observed to change at a port by as much as an order of magnitude. Modeling is underway to assist in isolating the transport mechanisms involved and assist in quantifying the effect of varied pneumatic permeability on pressure propagation.

Laboratory work is underway at BYU to more carefully isolate the mechanisms of diffusive transport and pressure fluctuation in unsaturated conditions. A sealed soil column has been packed with sand and instrumented with a contaminant reservoir at one end and concentration sensor at the other. A mechanical syringe is used to vary the pressure within the tube, and pressure sensors have been emplaced.

An affiliation has been established with researchers at the DOE Sandia laboratory to utilize a novel non-invasive vapor detector in our sealed-column laboratory work.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 757: Symposium II – Scientific Basis for Nuclear Waste Management XXVI , 2002 , II3.26
Copyright
Copyright © Materials Research Society 2003

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Buckingham, E., “Contribution to our knowledge of the aeration of soils,” U.S. Department of Agriculture Soils Bulletin No. 25 (1904).Google Scholar
2. Weeks, E.P., “Barometric Fluctuations in Wells Tapping Deep Unconfined Aquifers,” Water Resources Research, 15(5) 1167–1176 (1979).Google Scholar
3. Thorstenson, D.C., and Pollock, D.W., “Gas transport in unsaturated porous media: The adequacy of Fick's law.” Reviews of Geophysics. 27(1), 61–78 (1989).Google Scholar
4. Wood, W.W., and Petraitis, M.J., “Orgin and distribution of carbon dioxide in the unsaturated zone of the Southern High Plains of Texas,” Water Resources Research, 20(9), 1193–1208 (1984).Google Scholar
5. Severinghaus, J.P., and (many) others, “Feasibility of using sand dunes as archives of old air” Journal of Geophysical Research, Vol. 102, no. D14, p. 16, 783–17, 792 (1997).Google Scholar
6. Busenberg, E., Weeks, E. P., Plummer, L. N., and Bartholomay, R. C.. “Age dating ground water by use of chlorofluorocarbons (CCl3F and CCl2F2) and distribution of chlorofluorocarbons in the unsaturated zone, Snake River Plain Aquifer, Idaho National Engineering Laboratory, Idaho,” U.S. Geological Survey. (1993) WRIR 93–4054, 47pp.Google Scholar
7. Nilson, R.H., McKinnis, W.B., and Lagus, P.L., “Field Measurements of Tracer Gas Transport Induced by Barometric Pumping,” High Level Radioactive Waste Managemen,. Vol. 1 (1992).Google Scholar
8. Alzaydi, A.A.,. and More, C.A., “Combined Pressure and Diffusional Transition Region Flow of Gases in Porous Media,” AIChE J. 24(1) 35–43 (1978).Google Scholar
9. Weeks, E.P., “Field Determination of Vertical Permeability to Air in the Unsaturated Zone,” Geological Survey Professional Paper 1051 (1978).Google Scholar
10. Thorstenson, D.C., and Pollock, D.W., “Gas transport in unsaturated porous media: Multicomponent systems and the adequacy of Fick's la,.” Water Resources Research, 25(3), 477–507 (1989).Google Scholar
11. Massmann, J. and Farrier, D.F., “Effects of Atmospheric Pressure on Gas Transport in the Vadose Zone,” Water Resources Research, 28(3) 777–791. (1992).Google Scholar