Water Reuse

Indirect Potable Reuse

Groundwater Recharge

Groundwater Recharge is an application for reclaimed water that can be implemented in order to accomplish many goals. Those goals include stopping saltwater intrusion, providing further treatment for future reuse, augmenting aquifers, storing water for future use and to prevent ground subsidence. Clearly, some of these are related to future use of reclaimed water and others have a more direct and immediate purpose. For this reason, groundwater recharge is often used as part of a broader reuse strategy. In addition, groundwater recharge may also be a byproduct of some of the other reuse strategies such as agriculture reuse. There are several methods that can be used to recharge groundwater with reclaimed water. These include surface spreading, soil aquifer treatment systems, vadose zone injection and direct injection. Surface spreading, as the name implies, is simply allowing the water to flow naturally from the surface to the groundwater. Soil aquifer treatment systems (SATs) are similar to surface spreading, but they are designed in such a way that all the water can be recovered later in wells, drains or surface water. Vadose zone injection is similar to he first two in that the reclaimed water still flows through the soil. However, the main difference is that a well is used to deposit the water below the surface. Finally, direct injection involves injecting the water directly into the aquifer. This requires higher quality water since no filtering will take place in the soil. All of these activities should not be considered without appropriate attention paid to issues of contaminant transport and public health.

Sources:
Guidelines for Water Reuse. US Environmental Protection Agency. EPA/625/R-04/108. September 2004.