The first—and perhaps greatest—challenge in addressing ground water contamination is gaining an accurate understanding of the pollution plume’s likely flow path. Unfortunately, traditional methods for determining the potential routes of subsurface pollution require extensive drilling, a time-consuming and environmentally traumatic process. The imaging procedure detailed in this presentation provides accurate groundwater maps but requires substantially less drilling. As a result, this method entails fewer costs in terms of time, money and ecological disruption. Initial case studies indicate that this rapid and minimally invasive technique may be particularly well suited to the task of environmental diagnosis and remediation.

This procedure relies on the principles of Controlled Source-Frequency Domain Magnetics. First, electrodes are used to charge the groundwater in question with a low voltage electrical current. As the current flows through the water between the electrodes, it emits a magnetic field whose size, shape, magnitude and direction are characteristic of the surrounding aqueous system. This field is then read at the surface by a specially tuned receiver. The data thus generated can be used to create maps indicating the attributes of the subsurface water network, including potential flow paths. That same data can also form the basis of three-dimensional models of the site, which provide detailed insight into the depth and character of the aqueous network. Such information is of tremendous value in the difficult effort to remediate ground water pollution.

This technology has recently been deployed in a number of projects involving subsurface contamination. This paper discusses the results of its deployment in various ground water environments, from karst terrains in the upper Midwest, to the desert plains surrounding Nevada’s Lake Mead, to the resource-rich environs of southern Wyoming. This presentation offers both the theoretical science behind the methodology and the lessons learned from its recent applications.