The basement of Laura Holder’s 1925 bungalow looks like many others in her Milwaukee neighborhood. Dappled sunlight streams through glass-block windows onto an assortment of exercise equipment and her husband’s woodworking tools. An unfinished corner houses the washer and dryer and a second fridge and freezer. But instead of meat and leftovers, Holder’s basement freezer is full of dirt. Eighty-five bags of sediment, to be exact, double-bagged, numbered, and frozen solid. They were collected by biologists with the Wisconsin Department of Natural Resources (WDNR) and sent to Holder’s home, which…
