Groundwater-Kalamazoo River Interaction Near the Parchment City Wellfield, Parchment, Michigan
A detailed hydrogeologic study of the Kalamazoo River and its interaction with the groundwater was completed near Parchment, Michigan. The Kalamazoo River between Portage Creek and Allegan Dam is a Federal superfund site due to PCB contamination trapped in its sediments. The City of Parchment pumps all of its drinking water from a glacial aquifer 850 feet from the Kalamazoo River. This study focused on the hydrogeology and groundwater/surface interaction of the area through the use of surface and downhole geophysics, installation of monitoring wells and peizometers, seepage meters and chemical sampling. It was determined that the Kalamazoo River is receiving recharge from the adjacent aquifer, however, it was seen in the seepage meter results that this recharge can fluctuate with pumping rates and river stage. The chemical sampling data demonstrated the interaction of the river with the wellfield and the variability of groundwater movement. Although the data does not show impact to the wellfield, it does show that pumping in the wellfield does cause shifts in the hydraulic gradient in the aquifer and in the distribution of chemical species. These pumping induced gradients coupled with high stream stage appear to induce river water to flow towards the wellfield.