Hello aspirant

Wastewater refers to the spent water that is discharged by sources such as domestic (homes), commercial (shopping malls), industrial (factories), infiltration and inflow (pipes) and stormwater (excessive rainfall/snow melts). It consists of 99% of water and 1% waste. Depending on the sources, the wastes may include organic matter (human faeces), detergents, heavy metals, solid matter, microorganisms and floating debris among others. Sewer systems involving drains, pipes, and pumps then carry the wastewater to a treatment facility.
Wastewater treatment plants are very important. Their role is to remove as much as possible the amount of pollutants and solids from the wastewater, restore its pH and disinfect it before discharging in water bodies such as rivers and seas. This process is carried out within technical and financial feasibility. Therefore, the treatment of wastewater is primordial; otherwise, the polluted water will infect fresh water bodies, disrupting their ecological balance and endangering the flore and fauna.

Hope this helps. All the best.