Sewage Treatment Plants (STP)
A Sewage Treatment Plant (STP) is a facility that cleans the wastewater from households,
businesses, and sometimes industrial sources. The purpose of an STP is to remove
contaminants from the wastewater and produce an effluent that is safe to discharge into the
environment or reuse for other purposes. An STP also reduces the pollution and health risks
caused by untreated sewage. 1.An STP usually consists of three main stages: primary,
secondary, and tertiary treatment. In the primary stage, the wastewater is filtered to
remove large solids and grit. In the secondary stage, the wastewater is treated by
biological processes that break down organic matter and pathogens. In the tertiary stage,
the wastewater is further purified by chemical or physical methods to remove nutrients,
metals, and other pollutants.
