By John Bilotta
For parts of the state, groundwater recharge may be a necessary tool for meeting the water needs of growing communities, competing uses and natural systems. Evaluating the economics, policy, engineering and hydrogeologic considerations now will allow us to consider enhanced aquifer recharge when, where and if it is needed. A team led by the Water Resources Center has brought together experts across science, engineering, economics, and policy disciplines, along with outside experts and stakeholders to evaluate the need for managed aquifer recharge.
Changes in groundwater dependence and need, the magnitudes of the expected change in the seasonality and intensity of precipitation, evapotranspiration and altered hydrology are key factors that impact future recharge of aquifers. The study team will draw on successful examples of recharge to surficial aquifers and active recharge to confined or buried aquifers. These will be translated to the specific geologic conditions present in four study areas in Minnesota. Water sources like treated surface water or wastewater will be evaluated for their potential to recharge groundwater. Energy use and infrastructure costs are part of the equation and least easily understood.
Policy changes may be required to deploy recharge as a tool. The Groundwater Protection Act of 1989 has an anti-degradation clause that is interpreted by some to prohibit groundwater recharge. EPA ultimately gives authority for injection wells (except to sovereign nations like the Shakopee Mdewakanton Sioux). These and other policy barriers need to be evaluated before managed aquifer recharge can be deployed.
This project is assessing the possibility of aquifer storage and recovery (ASR) in four pilot areas:
- Straight River Groundwater Management area
- Southern Washington County
- Great Rochester region
The project is funded by a $350K grant from the Legislative-Citizen Commission on Minnesota Resources (LCCMR) and has an 18-month timeline that will conclude with a report to the 2021 legislature.
The interdisciplinary team includes:
- Carrie Jennings, Research and Policy Director, Freshwater Society and Adjunct Assistant Professor, Department of Earth Sciences
- John Bilotta, Senior Research and Extension Coordinator, WRC and Extension Educator, MN Sea Grant
- Lucia Levers, Research Associate, WRC
- Brian Bohman, Research Fellow, Freshwater Society and WRC
- Tony Runkel and a Hydrologist, Minn. Geological Survey: Aquifer and aquitard characterization
- Bill Arnold, Faculty, CEGE, U of M: Engineering analysis
- Peter Kang, Faculty, Earth Sciences: Aquifer storage and recovery through wells
- And three postdocs and research specialists