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Extended Time Monitoring Programs
Under RBCA guidelines, extended monitoring of vapors and ground water often substitutes for
remediation or is used in the period leading up to the implementation of remediation alternatives.
Vapor Monitoring Implants
Vapor implants allow monitoring of vapor plumes and the changes in ground water
plumes over time. The implants accurately define the vertical and horizontal distribution
of vapors, identifying varying sources, whether in soil, ground water or as a dense vapor
from surface sources. Vapor implants can be installed either singly in a hole at a
specified depth, or nested at up to 5-6 discrete depths, sealed from each other. The
implants are connected to the surface for sampling. The implants are steel, aluminum, or
plastic, and are equipped with inert tubing for sampling. Implants have been installed as
deep as 80 feet.
Ground Water Wells
Small-bore monitoring wells are significantly less expensive than traditional 4" wells,
saving installation time and money, and are constructed with NO IDW. Monitoring of
ground water can be accomplished using a variety of permanent and temporary small
bore well systems, deeper than 100 feet. PVC or steel screen and riser can be installed to
great depths and be set up with sand packs, bentonite seals, and bentonite-grout
construction. They can be finished with riser or flush mount completions. Peristaltic
pumps or bailers (including dedicated SS bailers manufactured by ESN) are used for
sampling. Under some circumstances, bladder pumps can be installed, as needed.
In addition, “PrePacked” well sections can be installed. These consist of small diameter
screened PVC with a sand pack and contain steel mesh screen. Available in 3 to 5 foot
sections, they can be threaded together to provide for nearly any screened interval. They
have been installed vertically and at low angles.
Both methods of using small diameter wells (ranging from 0.5" to 2" ID) are widely
accepted by State and Federal agencies.
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