Borehole geophysical logging can provide a wealth of information that is critical in gaining a better understanding of subsurface conditions needed for ground water and environmental studies. A geophysical log is a continuous profile, characterizing formation properties adjacent to a borehole or well. Using a logging system allows information to be collected in a fast, reliable manner.

Data is displayed in real-time, as the probe is raised or lowered, for immediate analysis. Multiple logs typically are collected to take advantage of their synergistic nature - much more can be learned by the analysis of a suite of logs as a group than by the analysis of the same logs individually. Brotcke Well & Pump's system can be used to collect gamma logs, single-point resistance logs, spontaneous-potential logs, and many others.

Gamma logs record the amount of natural gamma radiation emitted by the rocks surrounding the borehole. Clay- and shale-bearing rocks commonly emit relatively high gamma radiation. Single-point resistance logs record the electrical resistance from points within the borehole to an electrical ground at land surface. In general, resistance increases with increasing grain size and decreases with increasing borehole diameter, fracture density, and dissolved-solids concentration of the water. Spontaneous-potential logs record potentials or voltages developed between the borehole fluid and the surrounding rock and fluids.