ASR-MAR Webinar Series

ASR-MAR in Agriculture

Established in September 2019, the Aquifer Storage and Recovery - Managed Aquifer Recharge (ASR-MAR) Workgroup was formed to examine, discuss, and make recommendations to the GWPC Board of Directors regarding Aquifer Storage and Recovery (ASR) and Managed Aquifer Recharge (MAR) issues or topics.

Join us quarterly for webinars focusing on important technical issues surrounding ASR and MAR. 

Next Webinar:

October 3, 2022 | 12:00 PM - 1:00 PM (Central) 

Managed Aquifer Recharge Utilizing Riverbank Filtration and Groundwater Transfer and Injection: A Potential Technology for Sustainable Groundwater-Irrigated Agroecosystems

Andrew M. O'Reilly (Andy) | Research Hydrologist, National Sedimentation Laboratory, USDA, Agricultural Research Service

Long-term declines in groundwater levels in the Mississippi River Valley alluvial aquifer (MRVAA) threaten the sustainability of agroecosystems in the Lower Mississippi River basin dependent on the aquifer for irrigation water. To assess the potential for managed aquifer recharge to support irrigated agriculture in this region, the U.S. Department of Agriculture Agricultural Research Service, in partnership with local stakeholders and the U.S. Army Corps of Engineers, is conducting the Groundwater Transfer and Injection Pilot (GTIP) project near Greenwood, Mississippi. The system consists of one extraction well, a 1.8-mile pipeline, and two injection wells, with a design capacity of 1,500 gpm. Groundwater is filtered by passing through sands adjacent to the Tallahatchie River and subsequently is extracted, transferred, and then injected into a depleted section the MRVAA. Operational tests of 3- and 6-month duration have been completed, injecting a total of 550 and 575 ac-ft, respectively. I will summarize objectives and construction of the GTIP project and, based on some expected and unexpected experiences from the pilot testing, describe preliminary results and lessons learned.


Andy O’Reilly ( is a Research Hydrologist with the U.S. Department of Agriculture, Agricultural Research Service, National Sedimentation Laboratory, in Oxford, Mississippi. He earned a Bachelor and Master of Civil Engineering from Auburn University and Ph.D. in Civil Engineering/Water Resources from University of Central Florida. Previously he was as a Hydrologist with the U.S. Geological Survey Florida Water Science Center and Assistant Professor of Geological Engineering with University of Mississippi. Andy’s current research focuses on sustainability of groundwater-irrigated agroecosystems, including subsurface hydrology, contaminant transport and fate, data-driven and physics-based modeling, and engineering solutions including managed aquifer recharge and green infrastructure.



Innovative Drywell Designs and Applications for Enhanced Managed Aquifer Recharge

Scott A. Bradford, Ph.D. | Research Leader, USDA, ARS SAWS Unit

Managed Aquifer Recharge (MAR) is an important tool to mitigate the adverse effects of drought, floods, and changing climatic conditions. Flooding of agricultural fields (Ag-MAR) has being proposed to sustainably manage groundwater supplies, but potential limitations include low permeability soils, leaching of contaminants in the root zone, evaporation losses, and adverse impacts on crop health. This presentation highlights innovative designs and applications of drywells to overcome these limitations. A drywell is a infiltration system that has a small footprint at the land surface that is installed and releases water at varying depths into the vadose (unsaturated) zone. Field data and numerical simulations reveal that infiltration and recharge from a drywell can occur over a much larger area (e.g., 70 m diameter) than its surface footprint (e.g., <1.2 m diameter). The lowest levelized costs associated with recharging a given water volume occurred for smaller and deeper drywells that recharged water over a shorter timeframe.  Potential novel MAR applications of small diameter and deep drywells, including (i) repurposing of existing dried irrigation supply and domestic wells; and (ii) inclusion of drywells into existing irrigation canal systems. Widespread application of these MAR approaches is predicted to relatively rapidly recharge tremendous volumes of floodwater. Site-specific technical and regulatory hurdles still need to be addressed, and pilot-scale studies are therefore needed before large-scale implementation.


Dr. Scott Alan Bradford ( is a Research Leader and a Supervisory Soil Scientist in the USDA, ARS, SAWS Unit.  He is a fellow of the Soil Science Society of America, fellow of the American Society of Agronomy, recipient of the 2019 Don and Betty Kirkham Soil Physics Award, and the Editor-in-Chief for Critical Reviews in Environmental Science and Technology (2017-2020).

Dr. Bradford has authored over 164 publications on a wide variety of topics in soil physics, contaminant hydrology, and environmental engineering.  His research focus is currently on managed aquifer recharge.

Additional Authors:  

Scott A. Bradford1, Salini Sasidharan2, and Gordon Osterman1
1USDA, ARS, SAWS Unit, Davis, CA, USA
2Oregon State University, OR, USA

Please register for ASR-MAR in Agriculture on Oct 3, 2022 12:00 PM CDT at: 

After registering, you will receive a confirmation email containing information about joining the webinar.

The ASR-MAR workgroup was formed in 2019 to examine, discuss, and make recommendations to the GWPC Board of Directors regarding Aquifer Storage and Recovery (ASR) and Managed Aquifer Recharge (MAR) issues or topics. 

The GWPC ASR-MAR Workgroup has been identified in the U.S. EPA National Water Reuse Action Plan (Action 2.7.4) as a leader to increase understanding of current aquifer storage and recovery practices. As part of the plan, the Workgroup facilitates meetings to study and find solutions to the challenges currently limiting the use of Enhanced Aquifer Recharge (EAR) and ASR-MAR.

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