Pumping near a constant head boundary

Objectives: Quantify the drawdown in the potentiometric surface due to groundwater pumping near a constant head boundary.
1. There are many cases in coastal aquifer where you must calculate groundwater drawdown near an infinite source of water (i.e. the ocean or large lake).  As a result of this configuration it is necessary to account for this boundary condition.  To do this we use a method of images where a ‘fake’ or image well is placed in the lake or ocean an equal distance between the pumping well and the boundary.  In the problem below, it is your job to determine the water level in well B due to pumping in the pumping well at a pumping rate of 200 m3/day (36.7 gal/min).  Note that before pumping there is a gradient across the confined aquifer that shows water is flowing toward the lake.  Use the foldable aquifer model provided to answer the following question

A. Draw in map view a diagram showing the position of the pumping well, observation well (well A) and image well.

B. Determine the water level in well A after pumping has reached steady state.

C. Explain how the results would change if there was no initial gradient in the potentiometric surface prior to pumping.  In your description please state where you would expect to see the water level in well A.  

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