Septic is associated with anaerobic bacterial (sequence of process that use microorganisms to break biodegradable materials without oxygen) setting that builds up in tank. Septic tanks are used as wastewater treatment.



The French initially used septic tank system in 1876. In 1886, automated septic tank sewer system was installed in the USA, which is the same structure as the ones we are using now.

The septic tank system is composed of underground tank and filter structures.

There are two kinds of septic tanks; one is fiberglass/plastic tank and the other is steel tank. A fiberglass tank can last up to 50 years while a steel tank because of rust can only last up to a decade.

Septic tank systems have two divisions: the left and right divisions. The left division is the input pipe from the house and the right division is the output pipe going to the filter field. The tank is also divided into two to contribute into better waste material management.

The role of a septic tank is to strain waste that affects permeability of the soil in its drain field. Wastes are divided into different layers inside the left division of the tank. The solid and heavy waste (feces) forms sludge at the bottom, while light materials (fats, bits of food particles, and grease) float forming a primary layer of scum. A soup like layer forms between the sludge and scum layer. This layer is composed of hanging materials that are too light to sink and a little heavy to float (household chemicals and urea). The right division collects the liquid mixture or load from the left division.

Microbes from humans’ gastrointestinal tracts play an important role in the anaerobic process inside a septic tank. As the microbes set the process in motion, the activity inside the tank produces gas such as methane and hydrogen sulfide. The movement of the gas will then contribute to the anaerobic process stirring the three layers of waste inside the tank. In the end of the process, the solids will be changed into liquid. The liquid will then be absorbed and filtered by the soil in the drain field.

The quality of soil in the septic tank’s location is very important, because the soil microbes manage the wastewater disposal and treatment. Percolation test is done to measure the soils ability to filter wastewater. Soil composed of silt, sand, and clay is the ideal type of soil because of its permeability.

It is important that drain fields and the entire septic tank system are at least 100 feet away from any body of water to avoid any contamination possibilities. Keep drain fields away from plants, trees, and shaded areas. These things affect the wastewater treatment in the soil. Save a large space for your drain fields, just in case you’ll need a bigger septic tank system.

Well-maintained septic tank system can last for decades. Annual septic tank check up would also help prevent your septic tank from overflowing. Avoid clogging septic tanks with grease and solid garbage. Never light a match when checking septic tanks as gasses produced inside are highly combustible.