USGS Scientist Conducts Groundwater Slug Test

In this photo, USGS scientist Martha Nielsen conducts a slug test in a groundwater well completed in bedrock. During a slug test, a hydrologist causes the water level in a well to increase or decrease rapidly, while measuring the water-level response in the well over time. Hydrologists use this experiment to better understand how groundwater moves through the aquifer in the area of the well.

This October 2021 field work in Split Rock Lighthouse State Park, Lake County, Minnesota, was part of a USGS Upper Midwest Water Science Center study in collaboration with the U.S. Environmental Protection Agency Great Lakes Restoration Initiative to assess the importance of groundwater in the movement of chemical contaminants to Lake Superior.

You can also learn more about USGS groundwater technical procedures for slug tests and other field operations.