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The primary methods for groundwater sample acquisition are done by utilizing
the SP-15, SP-16 sampler or the Groundwater Profiler. The samples can be obtained
in a number of ways. The most common method utilizes polyethylene or Teflon-tubing
and a Tubing Bottom Check Valve. The check valve is attached to one end of the
tubing and inserted down the casing until it is immersed in groundwater. Water
is pumped through the tubing to the ground surface by oscillating the tubing
up and down, or pumping through a peristaltic pump  .
Collect the sample by withdrawing and draining the tubing.
The Groundwater Profiler
is able to conduct vertical profiling of groundwater quality from a discrete
interval using 6 in. or 12 in. (152 or 305 mm) screens. Profiling can be conducted
to determine vertical distribution of contaminants, especially in sandy or coarser
grained aquifers, as the tool is advanced incrementally into the formation. There's
no need to retract the Profiler after each sample is collected. Purging water
through the Profiler with a peristaltic pump as it is advanced minimized clogging
of the screen.
The Profiler allows the user to not only obtain high integrity, discrete
interval samples over a depth profile, but also lets the user conduct hydraulic
conductivity tests at each sampling depth (i.e. slug tests) to determine the
most probable contaminant flow paths.
Rather than small "port holes" that may
be prone to clogging, the larger screen area of this tool provides a much greater
surface area for the flow of groundwater into the system. This tool is 1.375
in. (35 mm) in diameter and can be telescoped through Geoprobe's 2.125-in. (54
mm) probe rods. Development of the screen can also be conducted at each sampling
depth to lower turbidity when required. Bottom up (positive pressure) grouting
can be conducted when an expendable point is used.
Groundwater Profiler individual parts, expendable points, and O-rings may
be purchased separately as needed. Complete kits are available with either a
6 in. or 12 in. screen interval and either a solid or expendable drive point
option.
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