AWWA ACE71068

To meet future water demands and the requirements of Miami-Dade County's 20-year water use permit (WUP), the Miami-Dade Water and Sewer Department (MDWASD) must implement the design and construction of the 21-million-gallon-per-day (mgd) South District Water Reclamation Plant (SDWRP). The facility will treat filtered secondary effluent from the MDWASD's South District Wastewater Treatment Plant (SDWWTP) using microfiltration, reverse osmosis, and ultraviolet advanced oxidation, to meet primary and secondary drinking water standards. Product water from the plant will be pumped approximately 6 miles to the proposed recharge site at the Miami MetroZoo, where it will be re-introduced into the Biscayne Aquifer, the local surficial aquifer. One of the facilities being considered is the use of existing and proposed lake system on the zoo site. The second facility type being considered is the existing moat that surrounds the Miami MetroZoo. Originally constructed as a secondary containment measure for the zoo, this moat is approximately 8 to 12 feet in width and 9 to 15 feet in depth, with exposed vertical limestone walls. Injection wells are the third recharge facility type under consideration; they would be used to introduce the water directly into the aquifer. The last facility type being considered is a covered rapid infiltration trench gallery. These trenches would be excavated into the limerock, to a specified depth and width, and filled with ballast rock and perforated pipe. These different recharge facilities were considered for single facility alternative or combined alternatives. The alternatives were modeled for mounding and solute transport potential. This paper describes the preliminary design of these recharge facilities. Includes 4 references, tables, figures.