Until recently, surface water reservoir construction has been the answer to extending transient surface water supplies. This option is now receiving greater attention in Texas. Most ASR applications involve storing water in a suitable aquifer through wells during times of excess for future recovery to meet demands. A schematic of a typical potable water ASR system is presented in Figure 1. Cost Savings A significant advantage of ASR over other alternatives is lower capital costs for equivalent peak capacity.
Costs are dependent primarily on storage zone depth and well yield.
Other considerations are design lift, well completion, and recovered water disinfection requirements. Examples of ASR costs compared with conventional approaches are presented in Figure 2. The utility serving Kitchener-Waterloo, Canada was considering constructing a lengthy pipeline to either Lake Ontario, Lake Erie, or Lake Huron to meet projected demands. Potable water supplied to the Florida Keys is produced at a wellfield and water treatment plant at Florida City on the mainland. The water is piped as far as Key West through a 120-mile long pipeline which crosses 45 bridges.