Geology is the limiting factor in the study of virtually every waste disposal site. While aquifers and confining layers may be defined by borings, the hydrology is often complicated by channels, faults, clay lenses and other geologic realities. Site input is dependent on sources such as barrels, drain pipes and disposal points. It would seem that the situation is ripe for the application of geophysical measurements. In many cases, the geology and various contaminant sources offer physical contrasts ammenable for study. Geophysics is an ideal, non-intrusive, investigative tool. 

Geophysical techniques for waste site study include seismic reflection and refraction, ground penetrating radar and active and passive electromagnetic, magnetic and resistivity profiling. Applications range from simply finding drums to tracking contaminant plumes. Examples of each of these in the Houston area will be discussed and an application rationale developed. Perhaps more importantly, the role of geophysical measurements within the current regulatory framework will be discussed. There are disadvantages inherent in the uncertainty of interpreted, indirect measurements where certainty is required. On the other hand, a continuous, objective picture of the shallow subsurface is very useful. The role of geophysics is an evolving one, and the future promises to be very interesting.

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