Millions of American homes that do not have access to a municipal sewer system rely on septic systems for the treatment and disposal of household wastewater. A septic system is a relatively simple, low maintenance system that ordinarily works well when the system has been properly designed, installed and cared for.
A septic system has two main components: a septic tank and a drain field (also called a leach field). Most septic systems operate solely on gravity and do not have any electrical components. A septic system has to be designed and installed to allow household waste to flow from the home to the septic tank and then on to the septic field.
Household waste water is collected in a large drain line which routes it to the septic tank. Once in the tank, the solid material sinks to the bottom forming the sludge layer and oily or greasy material floats to the surface and forms the scum layer. The middle layer, called the effluent, then flows thought an outlet pipe to the drainfield which is a series of perforated pipes buried underground in a bed of gravel.
The effluent percolates through the gravel and into the soil below. As it percolates through the soil, the effluent is filtered and treated through natural biological processes.
Meanwhile, the septic tank has baffles that prevent the scum layer from flowing out of the tank with the effluent. Bacteria and enzymes naturally reduce the amount of sludge and scum in the tank, but eventually the accumulation of sludge and scum will need to be pumped out of the tank. Septic tank pumping every three to five years will keep most septic systems in good shape.
