Feasibility of Using Reclaimed Water for Aquifer Recharge In the Tampa Bay Area

In 2008, the Southwest Florida Water Management District (SWFWMD) initiated the Regional Reclaimed Water Partnership Initiative Project to work with utilities in the Tampa Bay Area to identify options for maximizing the beneficial use of available reclaimed water flows.  One of the options identified was to use highly treated reclaimed water to recharge the Upper Floridan aquifer (UFA) to improve declining water levels and provide the opportunity for additional groundwater withdrawals.  Because aquifer recharge using reclaimed water has been successfully implemented in other areas of the country, a feasibility study was conducted in 2009 that assessed the practicability of implementing this option in the southern Hillsborough and Polk County areas.  The scope of work involved three main tasks:  (1) assessing regulatory requirements; (2) quantifying water level improvements and potential groundwater withdrawals; and (3) performing cost analyses. 

Findings from the study indicate that it is possible to develop direct and indirect aquifer recharge projects to improve UFA water levels and provide opportunities for additional groundwater withdrawals in the area.  Direct aquifer recharge (e.g., recharge wells) is most optimally located in coastal areas where the native aquifer water quality is poor and regulatory requirements are less stringent than more inland areas.  Indirect aquifer recharge (e.g., rapid infiltration basins) would be most beneficially located in areas where the surficial sands are thick and a good connection to the underlying UFA exists.  Depending on location, potentially up to 90 percent of recharged water quantities could be used as drawdown mitigation offset for future additional groundwater withdrawals.  Estimated costs are comparable to costs of other planned alternative water supply projects. Results from this study can be used by water suppliers to determine if these concepts can be incorporated into their water supply plans.  More site specific assessments including aquifer metals mobilization studies are needed, however.