Wastewater reuse is the use of treated wastewater to replace or augment the use of water for non-potable uses, such as landscape and agricultural irrigation and industrial water supply, and for indirect potable uses, including groundwater recharge and surface water augmentation. Indirect potable reuse), involving the discharge of treated wastewater to public sources such as rivers, lakes, or aquifers, is more widely encountered. However, direct potable reuse (e.g., The Omni Processor, toilet to tap) is an increasing trend worldwide, particularly in water scarce areas, if membrane treatment, advanced oxidation, filtration, and disinfection are provided. Secondary treatment water, with or without nitrogen and phosphorus reduction, is filtered and then disinfected for irrigation use for landscape or other non-potable (and sometimes potable) needs. The treated wastewater from cluster systems, satellite systems, or centralized systems can be used for a broad range of community sizes for irrigation or other non-potable uses. Small scale wastewater reuse is also being employed at, for example, resort communities or for agricultural purposes.

‍