Polk County Groundwater Recharge Investigation
Jones Edmunds conducted a Groundwater Recharge Investigation with Polk County Utilities in the County’s Northeast Regional Utilities Service Area (NERUSA). The project was cooperatively funded by the County and SWFWMD and examined the benefits of using reuse water to indirectly recharge the Floridan Aquifer via rapid infiltration basins (RIBs).
Jones Edmunds conducted extensive desktop and field investigations and developed a subregional groundwater model to better evaluate the effects of recharging the Surficial Aquifer System (SAS) and Upper Florida Aquifer (UFA) and to quantify the additional groundwater that could be available as a result of beneficial recharge of the aquifer system. As a result of this project, the County should have an option for offsetting the potential impact of future groundwater withdrawals and be able to beneficially use 100% of its reclaimed water flows while providing opportunities for developing additional water supplies in an area where water supply options are limited.
The first phase included the preliminary assessment of two sites within the NERUSA – the Northeast Regional Wastewater Treatment Facility (NERWWTF) and the Polo Park RIB site. The Preliminary Site Assessment included compiling and reviewing available regional and local hydrologic and hydrogeologic information and developing a preliminary groundwater model. The suitability of two sites for aquifer recharge was also investigated. Building on the Preliminary Site Assessment, Jones Edmunds prepared a Detailed Field Investigation Plan that provided guidelines for testing objectives; proposed locations for additional monitoring wells and boring logs; and developed data collection plans, aquifer performance testing (APT) procedures, multi‐electrode electrical resistivity (MER) survey, and load‐testing procedures used in the Detailed Site Assessment.
We conducted the detailed field investigation of the NERWWTF site to collect the information required to further identify and better understand the subsurface condiDraft Outline and Preliminary Texttions at the NERWWTF site and to help us calibrate the site‐specific transient groundwater model using the site-specific aquifer properties so that it could be used to predict the site’s ability to offset the potential impact of future groundwater withdrawals through beneficial recharge of the aquifer system. The site‐specific field tests included SAS and UFA performance tests, slug tests, double-ring infiltrometer tests, soil analysis, MER survey, and full‐scale loading test. Using the this information, Jones Edmunds prepared a subregional groundwater model to evaluate the potential for recharging the UFA via RIBs, including how the proposed recharge can offset the potential impact of future withdrawals in the NERUSA. The model was calibrated for steady‐state and transient conditions.
Jones Edmunds performed a GIS‐based wellfield siting analysis to determine the most suitable withdrawal locations to take advantage of the County’s beneficial recharge. This analysis included evaluating potential sites’ proximity to wetlands, MFL and stressed lakes, and the potential recharge locations.