Effluent is the wastewater discharged from a plant after treatment.

• A. Influent
• B. Coastal water
• C. Fresh water
• D. Effluent

Answer: (D)

In wastewater treatment, water that enters the plant is called the influent, it’s treated, and the water that exits after treatment is called the effluent. The term effluent specifically describes the discharged water after processing, which is exactly what the statement defines. The other terms refer to different concepts: influent is the untreated wastewater coming into the plant, while coastal water and fresh water describe types of water in the environment, not the discharge from a treatment facility.