Septic System Design
The main function of a septic tank is to collect, treat and dispose of sewage produced in the bathroom, kitchen and laundry rooms. Septic tanks are mostly designed for rural and suburban homes where sewage treatment plants are not available. The main function of the septic tank is to treat the household wastewaters and get rid of disease-causing germs and pollutants.
A septic system design will have a septic tank, a drainfield, and the soil under the drainfield. The septic tank is normally made out of concrete and holds about 1,000 gallons, but the number of bedrooms in the house is what legally determines its capacity. Buried outside the home, the septic tank is connected to a buried pipe that moves the wastewater to the drainfield for further treatment. The wastewater is delivered to the soil where the germs and chemicals are removed before they reach any other adjacent water.
The main function of the septic tank is to retain the solids inside and release the liquids to the drain field. This is done after the heavier materials sit on the bottom of the tank (forming a sludge layer) and the lighter greases float at the top of the tank (forming a scum layer). The liquid that leaves the septic tank is then filtered at the drainfield where germs and viruses are filtered by the soil until they are destroyed.