Microbial Processes Contributing to the Clogging of Aquifer Storage and Recovery (ASR) Wells in South Florida

This metadata record describes data collected from laboratory experiments designed to characterize the microbial processes that contribute to clogging (i.e., bioclogging) of wells used for recharge (i.e., injection) of fresh surface water into specific aquifer zones (Upper Floridan Aquifer [UFA] and Avon Park Permeable Zone [APPZ]) as part of water storage technology of aquifer storage and recovery (ASR). Solid rock core samples were collected from three wells (ASRC38S, ASRL63S and ASRC59; abbreviated to C38S, L63S, and C59 henceforth) near Lake Okeechobee, Florida, that have been designated as injection well sites for ASR wells as part of the Comprehensive Everglades Restoration Plan, on July 22, 2022 (C38S/UFA), May 22, 2023 (C38S/APPZ), July 7, 2023 (L63S/UFA), July 13, 2023 (L63S/APPZ) and November 15, 2023 (C59/UFA and C59/APPZ). The cores were crushed and sieved to a specific size, and this sized material was used to pack four columns: two columns for each well and aquifer storage zone (e.g., C38S/UFA and C38S/APPZ) (ATSM International, 2020; Rinck-Pfeiffer and others, 2000). Within each set of paired columns, one column was allowed to be colonized by native groundwater microbial communities (i.e., C38S/UFA Biofilm Positive column) by being connected to a continuously flowing source of native groundwater, either the UFA or APPZ, depending on the source of the packed core materials, for between two and four months. Prior to starting each experiment, pressure sensors were inserted into each column (Rinck-Pfeiffer and others, 2000). Each experiment was initiated by respectively pumping native groundwater from the UFA or APPZ into the UFA/Biofilm Positive and Negative and APPZ/Biofilm Positive and Negative columns for one week to geochemically condition the columns before starting the recharge phases of the experiments. Water collected from the Kissimmee River confluence with Lake Okeechobee was used as the recharge source water and was pumped through both the UFA Biofilm Positive and Negative and APPZ Biofilm Positive and Negative columns. During each experiment, pressure data in kilopascals (kPa) were recorded at specific locations along the vertical axis of all columns (Rinck-Pfeiffer and others, 2000). Additionally, pump rates into the columns were closely maintained at 5.00 milliliters per minute (mL/min). These data were used to calculate the hydraulic conductivity (meters/day) for all experiments (Sanchez-Vila and others, 2006). In addition to column pressure and flow rate data being collected, samples were also collected from native groundwater sources, Kissimmee River and from the column inputs, discharges and porewater after a static storage period for geochemistry, nutrients, dissolved gases, and organic carbon substrates to characterize microbial community preferential growth rates on selected organic carbon substrates.