Septic tank

A septic tank is a pre-treatment structure designed to retain settleable matter present in black water (WC) from residential homes.
It consists of a plastic tank buried in the ground, which is divided into two compartments. Wastewater enters the first compartment, where solids settle to the bottom and form a layer of sludge. Fats and oils float to the surface, forming a layer of foam. The wastewater then passes into the second compartment, where it undergoes a second settling stage. Anaerobic bacteria in the septic tank break down the organic matter in the wastewater, reducing the amount of solids and grease.
​Treated wastewater exits the septic tank and is discharged to the leach field, where it is filtered through the soil. The leach field consists of a network of perforated pipes buried in the ground, allowing the treated wastewater to infiltrate into the soil. The soil acts as a natural filter, eliminating bacteria and viruses present in the wastewater.