DESCRIPTION OF APPROACH
This Manual describes procedures that the Agency believes are the most appropriate
for designing, installing, and operating a detection monitoring system. This Manual also
describes the basic approach that an owner/operator should take in designing a detection
monitoring program. Figure 1 outlines this basic approach. Briefly, the steps are as follows:
Define the data that are required from a regulatory perspective, and develop
technical objectives to meet those requirements (Chapter Three).
Steps 2, 3, 4, and 5 are considered the hydrogeologic investigation for the site (Chapter Four).
Perform a preliminary investigation. The preliminary investigation is a
comprehensive review of existing information relating to the site. This
includes a thorough review of available literature and, if available, existing
field data. The purpose of the preliminary investigation is to characterize, to
the extent possible, the hydrogeology of the region and the site, and to gather
information that will be useful in planning field investigations. The
preliminary investigation also includes characterizing the chemical and physical
properties of the wastes or constituents of concern to the extent that this
information is available.
Develop, using regional and site specific data, a conceptual model of site
hydrogeology. The conceptual model should be based on the regional
hydrogeology and on the preliminary investigation, and should be used as the
basis for designing field investigations at the site.
Perform field investigations at the site. The field investigations will include
one or more of the following techniques:
Subsurface boring programs;
Laboratory analyses of soil, unconsolidated material, and rock samples;
Geologic and hydrogeologic analyses;
Electric cone penetrometer surveys; and