A Forensic Approach to Solve a Ground Water Contamination Problem

In 2000, a subdivision outside a small city in southeast Texas discovered that the water supply wells that individual households had drilled were contaminated with trichloroethylene or TCE as it is commonly called. Since the extent of TCE contamination seemed to extend for over a mile in length, it was thought the “event” or “events” leading to the contamination had occurred some years ago. The shape of the plume seemed to indicate that the source of the TCE contamination originated at a closed industrial facility located approximately 600 yards north of the subdivision. However, the width and shape of the plume implied that there might have been more than one source or that ground water flow had shifted direction in the past. Finally, one particular well serving a small commercial facility located at the western edge of the plume seemed to have the highest concentration of TCE.While the closed industrial plant was already subject to a state-led voluntary cleanup, the subdivision residents and nearby facilities whose wells had been impacted joined forces and sued the closed plant's owners for damages. The closed plant's owners, while not admitting any liability, agreed to install temporary carbon adsorbers on each contaminated well while the field investigation to determine the plume's parameters proceeded under state guidance and oversite. Since the timing of the field investigation and the lawsuit did not precisely coincide, it was necessary to accumulate data to support the plaintiff's lawsuit while at the same time refute the defendant's attempt to deflect responsibility for the TCE contamination. Superimposed on this scenario was the constraint to not independently conduct a field investigation to support the plaintiff's allegation. Thus, it was important to analyze the existing and evolving data to support the case, ensure that the conclusions reached were scientifically supportable, and refute the defendant's attempts to “blame someone else” for most if not all of the ground water TCE contamination. The result was that forensic methodology, which is the application of the art and science of engineering in matters that will or may ultimately appear in court, was used to characterize the history, source, movement, and present disposition of the TCE ground water plume.