Proceedings of the 2022 Mississippi Water Resources Conference

Year: 2022 Authors: Mamud M.L., Hickey C.J., Holt R.M., Wodajo L.T., Rad P.B., O'Reilly A.M., Bolton W., Wren D.

Groundwater flow induced by pumping from an aquifer near a river generates Streaming Potential (SP) signals that can be recorded at the ground surface around a pumping well. The SP signal produced by pumping near a river is influenced by groundwater flow within an aquifer, water flow from the river into the aquifer, and mixing of waters with different chemical compositions and temperatures. SP measurements can be used to identify and quantify characteristic time scales associated with these processes. SP measurements were conducted around a groundwater extraction well drilled for an Aquifer Storage Recovery pilot project located about 40m away from the Tallahatchie River in Shellmound, MS. SP data were recorded at 5 minute intervals using 80 non-polarizing CuSO₄ electrodes in a radial pattern centering on the extraction well. Pumping rates varied from ~300 to ~1500 gallons per minute over a ~4 hour period. Time series and spatial distribution of SP data shows that the river might have interacted with groundwater after 1 hour of pumping at an extraction rate of ~1500 gallons per minutes. This preliminary study suggest that measured SP data can be used to identify surface-groundwater interaction. Furthermore, hydraulic conductivity of aquifer, aquitard and riverbed; specific storage; and hydraulic head could be estimated from inversion of SP data.