CHAPTER TWO

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:

STEP 1

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).

STEP 2

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.

STEP 3

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.

STEP 4

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;

Mapping programs;

Electric cone penetrometer surveys; and

November 1992

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