Pumped from the vast layers of bedrock beneath our feet, groundwater is the source of drinking water for two-thirds of people living in Wisconsin. According to geochemist Matt Ginder-Vogel, what’s in that water is largely influenced by what’s in the rock. [caption id="attachment_3949" align="alignright" width="175"] Matt Ginder-Vogel is researching geogenic contaminants in public wells across Wisconsin. Photo credit: UW–Madison Department of Civil & Environmental Engineering[/caption] “Groundwater is not a lake underneath the ground. It’s water that’s in tiny pore spaces in the rock,” said Ginder-Vogel, an associate professor in the UW–Madison Department of Civil and Environmental Engineering. “So, it really interacts with the rocks around it.” Under the right conditions, this interaction can cause naturally occurring or “geogenic” contaminants—like radium, arsenic, uranium and manganese—to leach from bedrock into groundwater. Just…