the reclaimed water storage tank at the head of the AWTF if the treated water is determined not to meet the water quality requirements for aquifer injection.
A pilot study is necessary to develop design criteria prior to finalizing the AWTF process design. Additional treatment processes that may be incorporated into the AWTF include softening ahead of the RO process to remove calcium and other ions that could potentially precipitate on the membranes at higher water recovery rates. Operating the RO system at a higher recovery rate will reduce the amount of brine reject produced as well as increase the amount of water available for aquifer injection. An ion exchange could potentially be incorporated if the RO process did not adequately remove specific ions.
National Research Council, Committee to Evaluate the Viability of Augmenting Potable Water Supplies with Reclaimed Water. Issues in Potable Reuse. National Academy Press, Washington, DC: 1998.