Can a geothermal energy system raise the temperature of nearby groundwater? If it does, could that affect a nearby trout stream? Will higher temperatures dissolve more chemicals into the groundwater? Dave Hart, a hydrogeologist at University of Wisconsin – Extension’s Wisconsin Geological and Natural History Survey, is collecting the data to answer these questions.
In cooperation with Professors Dante Fratta and Jim Tinjum, of the UW-Madison College of Engineering, and Prof. Chris Choi of CALS, Dr. Hart will install five monitoring wells to evaluate the effect of a large groundsource heat pump system on groundwater temperature and groundwater quality.
“Groundwater remains at a constant temperature – unless you constantly change its temperature with a heat pump system” said Hart. Depending on the design of the system, the groundwater temperature may not recover from the heat pump system and that could result in higher temperatures where the groundwater discharges to springs, streams or lakes. Increased temperatures may also result changes to the water chemistry, as well. “We will be looking at this system to see if its temperature impact extends to local surface water,” said Dave.
The results of this study will be used to design more efficient and environmentally friendly geothermal systems.