Electricity, Groundwater Flow and Leak Detection in Landfill Liners An Environmental Geology Laboratory Developed by: Dr. Gregg Bluth, Michigan Technological University Objectives Demonstrate and learn about the similar properties of electrical and fluid flow. Analyze systematic measurements and learn how to draw contour lines and flow paths. Apply the above techniques to an environmental geology problem - that of locating landfill liner leaks quickly and efficiently through geophysical analysis. Introduction This laboratory was originally designed for an introductory environmental geology course. Waste management, pollution prevention systems, and groundwater systems are all interrelated, and so this laboratory would fit with any one of these topics. The main focus of this lab is to demonstrate how basic science principles, for example electrical flow, can be adapted to study natural systems and thereby provide valuable and unique information. Ideally, this lab would form part of a unit including theory (text and lecture), laboratory (modeling experiments), and field observation (trip to landfill). Landfills are designed to contain manmade waste products and isolate them from the environment. They are typically constructed with a layer of some type of synthetic membrane or lining under its base. This is a technically difficult process to install and most landfill systems develop leaks resulting from incomplete seams on the liner and weaknesses in the liner itself. Once the landfill is in use, the liner can also become damaged from loading and settling. If the leakage is severe, the liner must be repaired. The problem is, how to find the leak? A colleague of mine, Dr. Charles Young, adapted this technique to analyze the Delta County, MI landfill. Local wells were being contaminated, but it was not certain if the culprit was the landfill or some other dump site. Using the same methods demonstrated in this lab, Dr. Young was able to very quickly establish multiple leaks in the landfill, and their locations, thus saving the county a great deal of time and expense. I am writing this lab assuming little previous knowledge of electrical circuits or of voltage testing. This laboratory is divided into four sections: 1, the voltage meter; 2, a primer on taking measurements of a circuit and using them to make a contour map; 3, the lab itself; and 4, analysis of the data, and a few suggestions for future experiments. Everything in this write-up, along with links to related web sites, can be accessed through a web page we designed for PACE:http://www.geo.mtu.edu/outreach/landfill/ One last thing: remember in this laboratory experiment you are not dealing with a perfect system. Batteries wear out, connections are not complete, meters break. Sometimes you get some unusual results, but part of the learning process for this lab is dealing with unexpected conditions and problems. Be ready for anything, don't be afraid to stray from the directions and try things out on your own... oh, and have fun!