AWWA REUSE52085

The Biscayne Aquifer is a G-2, sole source aquifer, located in Broward and Dade Counties in southeastern Florida. It is the only freshwater source in the area that is capable of providing sufficient quantities of water to meet the needs of a human population. As a result, most utilities located in southeast Florida rely on the Biscayne Aquifer System for their raw water supplies. Fortunately, it is one of the most prolific surficial aquifer systems in the world. The quality of the water along the coast is relatively good, although it diminishes inland and at the saltwater interface near the coast (due to higher total organic carbon and higher chlorides, respectively). Recharge occurs primarily via rainfall, with some lateral movement from the Everglades and canal systems from Lake Okeechobee 100 miles north. Extensive canal systems are used with the intent on providing both drainage and stability in water levels. However, the 'stabilized' water levels are up to four feet lower than historical levels, and many flow directly to saltwater bodies which now allows saltwater to migrate inland, displacing or replacing the native fresh water. As a result, areas of the aquifer are no longer usable as a drinking water source. The City of Hollywood, Florida, has attempted to address this problem by investigating the use of a hydrodynamic barrier to retard or reverse the saltwater intrusion, using reclaimed water as the injectate. However, an issue of concern is the risk of recovery of pathogens in groundwater from the aquifer. This paper discusses the risks posed by pathogens and work completed to date to define the geologic parameters for injection wells.