Another classroom activity, this one using a scenario of investigating groundwater contamination at a gas station to reinforce some basic concepts about hydraulic head and groundwater flow. It’s based on a lab by Karen Kortz at CCRI which I stumbled across on the SERC website. I expanded the grid a bit, put together a slick spreadsheet that can be used to recall the data efficiently, shortened it up to take up a little less class time, and added a few questions related to real-world site investigations. It’s probably appropriate for any intro-level class that discusses groundwater, be that high school or college.
It goes like this: student groups select three locations to drill monitoring wells at a gas station where underground storage tanks were found to have leaked. I tap the locations into the spreadsheet (i.e. K7, M22, Q13) and it brings up the head in the well and the concentration of benzene in a sample from the well. They work out flow direction and then get to pick three final monitoring wells. After that, they’ve got to make a best guess of flow direction and contamination extent, and think about risks to surrounding homes. If you can, it’s great to show them a map (or some examples) of contaminated sites in your site after this. (Here’s Wisconsin’s, for example.)
Feel free to use/adapt. Ideas to extend or improve the activity are also welcome.
First sheet of spreadsheet is data lookup form to use in class. Second sheet shows head gradient (slightly distorted geometrically), and third shows benzene concentrations. One interesting thing to do is compare estimates from different groups to “reality” to demonstrate how imperfect interpretations from real-world data are.