Is it all
that easy to re-direct ground-water flow, by pumping ground water from a
well, so that only clean water flows beneath your basement preventing future
exposures of potentially cancer causing vapors into your home from toxics
such as benzene dissolved in the ground water from a nearby gasoline
 |
spill originating at
your local service station? There are a number of locations depicting possible
recovery well locations in this first figure. Remember that a common purpose
of ground-water pumpage is to influence clean ground-water to flow beneath
a house so that future seeps of ground water are free of contamination;
thereby, eliminating vapor generation in your home basement. Does it matter
where a single recovery well is to be located? Can anyone of these potential
recovery well locations be used to pump ground water so that we can re-direct
contaminant-free ground water to flow beneath your home replacing the contaminated
ground water now present there? The answer is no. Location..., Location...,
Location! The location that the recovery well is to be placed is penultimate
to the influencing clean ground water to flow beneath a structure in a timely
manner.
 |
In this second figure,
the plume is split at the downgradient side of the house. What is the advantage
to locating the recovery well so close to the upgradient (higher water table
elevation) side of the house so that the plume is split on the downgradient
(lower water table elevation) side of the house? In this situation the plume
is split, but unfortunately the capture zone is located beneath the house.
The capture zone is established to influence the transverse-lateral extent
of contaminated ground water to flow within its boundaries and into the
recovery well; and, to influence clean outer ground-water flowpaths to cause
the plume to be split. In the scenario depicted by this figure, the capture
zone is influencing contaminated ground water to flow beneath the house.
Obviously, the recovery well is located too close to the upgradient side
of the house. Unfortunately, I have all too often witnessed a recovery well
being installed so that the stagnation point is located below the home to
be remediated. |
