Which statement correctly describes indirect potable reuse?

• A. Directly into the drinking water supply
• B. Groundwater or surface water
• C. Water treatment facility effluent used for irrigation
• D. Industrial cooling water

Answer: (B)

Indirect potable reuse hinges on using an environmental buffer between treated wastewater and the drinking-water supply. Treated water is released into groundwater or a surface water body, where natural processes provide further treatment and dilution. It is later withdrawn and treated again to meet drinking-water standards before distribution. This buffering step is what makes it indirect rather than direct potable reuse, where treated water goes straight into the drinking supply without an environmental buffer. Using treated effluent for irrigation is a non-potable reuse scenario, and industrial cooling water is another separate reuse purpose. So the statement that best describes indirect potable reuse is that water is returned to groundwater or surface water and later recovered for potable use.