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Chapter 16: Analyzing Barometric Pumping
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calibration process essentially determines values for the radial permeability (k r )in
the flow model case. Once calibrated the model needs only time series differential
pressure data to provide accurate predictions of induced flow through a well. If used
in conjunction with an analytical solution for the subsurface pressure, only time series
atmospheric pressure data are required for flow prediction. The flow model is most
sensitive to differential pressure values, intrinsic permeability, and to a lesser extent
zone thickness. It is relatively insensitive to values of porosity, average pressure,
and well radius. By simple measurements of surface pressure, both the pressure and
flow models can be used to predict the performance of a well under the influence of
barometric pumping and to estimate the expected range of flow rates and variability
to simplify and improve monitoring plans.

REFERENCES
Carslaw, H. S., and J. C. Jaeger, Conduction of Heat in Solids, Clarendon Press, Oxford, 1959.
Cooper, H. H., Jr., and C. E. Jacob, A generalized graphical method for evaluating formation constants and
summarizing well field history, Trans. Amer. Geophys. Union, 27, 526–534, 1946.
Hantush, M. S., Hydraulics of wells, Adv. Hydrosci., 1, 281–432, 1964.
Jacob. C. E., On the flow of water in an elastic artesian aquifer, Trans. Amer. Geophys. Union, 2, 574–586,
1940.
Jacob. C. E. and S. W. Lohman, Nonsteady flow to a well of constant drawdown in an extensive aquifer,
Trans. Amer. Geophys. Union, 33 (4), 559–569, 1952.
Looney, B. B., J. B. Pickett, and J. J. Malot, Pilot Test of a Vacuum Extraction System for Envi-
ronmental Remediation of Chlorinated Solvents at the Savannah River Site (U), WSRC-RD-91-19,
Westinghouse Savannah River Company, Aiken, SC 29808, 1991.
Massman, J. W., Applying groundwater flow models in vapor extraction system design, Journal of
Environmental Engineering, 115 (1), 129, 1989.
Neeper, D. A., Harmonic analysis of flow in open boreholes due to barometric pressure cycles, Journal of
Contaminant Hydrology, 60, 135, 2003.
Rossabi, J. and B.D. Riha, Passive control of VOCs using valved well heads: FY 1994 report (U),
WSRC-TR-94-0524, Westinghouse Savannah River Company, Aiken, SC 29808, 1994.
Rossabi, J. and R. W. Falta, Analytical solution for subsurface gas flow to a well induced by surface
pressure fluctuations, Ground Water, 40(1), 67, 2002.
Shan, C., Analytical solutions for determining vertical air permeability in unsaturated soils, Water Resour.
Res., 31(9), 2193, 1995.
Theis, C. V., The relation between the lowering of the piezometric surface and the rate and duration of
discharge of a well using groundwater storage, Trans. Amer. Geophys. Union, 2, 519–524,1935.
Weeks, E. P., Field determination of vertical permeability to air in the unsaturated zone, US Geological
Survey Professional Paper 1051, 1978.