ABSTRACT
Beyond the in situ geotechnical tests performed to evaluate strength and deformation (discussed in the last chapter) lie field and laboratory tests to evaluate aquifer properties and the environmental factors that affect the hydrogeologic system. Aquifer properties may include hydraulic conductivity and porosity of individual samples, hydraulic conductivity of the area immediately adjacent to boreholes, or larger scale pump testing to evaluate large volumes of aquifer or confining unit materials for a wide variety of indices. These tests can also include chemical and recharge evaluation of subsurface units. A number of factors that must be considered during any environmental sampling and testing program are as follows:
1. Are the tests relevant to the particular problems being considered? For example, when hydraulic conductivity parameters are required, the soil or rock aquifer stressed by the test should be subjected to pumping stresses that are as close as possible to both the initial and resultant changes of stress that will occur in the full-scale situation. In other words, vertical hydraulic conductivity determined from laboratory permeameter tests may have little relevance to the horizontal hydraulic conductivity values necessary to design and operate a full-scale pump and treat system.
