How Septic Systems Works
Septic Systems are an additional improvement to homes used when sewage treatment plants are not accessible, mostly in rural or isolated homes without a sewer system available. However, the treatment is not complete as it is in a Sewage Treatment Station.
Septic Systems are fundamental when combating diseases, parasites and endemic diseases is a must, because they prevent the release of human waste directly into rivers, lakes or even on the soil surface.
A Septic System consists of two main components; the Septic Tank and a Drain Field.
The Septic Tank consists in a buried tank, that receives sewage (waste and wastewater mainly from the kitchen, bathroom or laundry), and retains the solid part of the sewage as it settles in the bottom. Once this is done the anaerobic bacteria acts on the solid part of the decomposing sewage. The result of this decomposing of the sewage waste is that it becames less organic thanks to the bacteria in the tank removing about 40% of the biological oxygen demand.
As the water enters the tank, the water that was already inside moves and flows into the drain field. The drain field is typically made out of a series of perforated pipes that distribute the effluents into the soil to supplement the biological process of purification and to eliminate any risk of contamination; this liquid cannot be released directly on the ground as it still contains organic matter and germs.
Septic tanks should not be placed too close to houses (to prevent bad smell) nor too far away (to avoid very long pipes, which are more expensive and require deeper tank due to the trim of the pipeline).
They must be built on the side of the bathroom to avoid bends in the plumbing. Should also be built at a lower level of the ground and away from wells or from any other source of water abstraction (at least 30m away), to prevent contamination in case of a possible leak.
The septic tank has been used for little more than 100 years. It was the first unit invented to treat sewage and today is the most extensively used.
The frequency of cleaning that a Septic System needs can be estimated by the size of the tank and the amount of people residing in the house. The use of garbage disposal can also increase the amount of solid residues.
Preventive and Periodic cleaning and maintenance of the septic tanks and system is the best approach to maintain the Septic System working as the solids will build up in the tank over time.
