The Full form of STP is Sewage Treatment Plant. STP is a facility designed to receive the waste from commercial, industrial, and domestic sources and filters it to remove the harmful substances that deteriorate the quality of water and affect public health and safety when discharged into canals, rivers, and other water bodies. A typical Sewage Treatment Plant is generally made up of a one-piece vessel that performs 3 different functions. It acts as a primary settlement tank, biozone chamber, and a humus chamber. The primary settlement tank separates the liquids and solids by moving the liquid into a chamber, called the biozone chamber.

The sewage and wastewater are fed into the main settlement tank where liquids and solids are separated, and the liquid is then passed into the biozone chamber. The biozone chamber contains the good bacteria that can breaks down the waste. This chamber has the perfect conditions to populate the bacteria and do this job. The bacteria help in digesting organic matter present in the liquids, which purify the water to a high level before draining. The humus chamber receives the treated sewage from the biozone chamber. The waste is around 95% clean when released from the final chamber and is ready to be discharged into local canals, ponds, and land drainage systems.