The microorganisms used to treat wastewater are the same as those found in rivers and lakes.

• A. True
• B. False
• C. The microorganisms used to treat wastewater are the same as those found in rivers and lakes.
• D. They are not used in treatment.

Answer: (C)

Wastewater treatment relies on microorganisms that naturally occur in the environment. The processes use the same kinds of bacteria and other microbes you’d find in rivers and lakes, simply provided with conditions (oxygen, nutrients, time) that let them multiply and break down organic pollutants. These microbes aren’t exotic or specially invented for the plant; they’re the same community of organisms that naturally live in natural waters. So, the statement is true: the microorganisms used to treat wastewater are the same types found in rivers and lakes.