What are the two common strategies for water reuse and their applications?

• A. Water reuse is limited to non-potable applications.
• B. Non-potable reuse includes irrigation and toilet flushing, while potable reuse involves advanced treatment for drinking.
• C. Potable reuse can be achieved with simple filtration.
• D. Water reuse means discharging treated water back into rivers.

Answer: (B)

Two common strategies for water reuse are non-potable reuse and potable reuse. Non-potable reuse uses treated wastewater for uses that do not require drinking water, such as irrigation and toilet flushing, which helps reduce demand on freshwater supplies. Potable reuse treats the water to drinking-water standards, often through advanced treatment processes, so the water can be directly or indirectly consumed as safe drinking water. This distinction matters because the level of treatment and the end use are closely linked: non-potable reuse operates with less stringent quality requirements, while potable reuse requires robust treatment to meet drinking-water quality.

The other choices don’t fit because: limiting reuse to non-potable ignores the reality that potable reuse is practiced in many regions; claiming potable reuse can be achieved with simple filtration underestimates the need for advanced treatment steps; and equating water reuse with discharging treated water back into rivers describes disposal, not reuse.