Basic Septic Tank Exposure

Septic tanks have become Marion County's latest preoccupation. An article on The Septic Tank and Its Use was created by the county Chief Sanitarian to educate the residents on what to expect from his septic tank. The purpose of the said article is to give information on what one can expect from his septic tank.

Septic tanks provide for a decent sewerage system for rural areas and newly built subdivisions. The use of a septic tank involves a set up of a filter bed or a tile disposal field for the excretion of effluent.

An appearance similar to that of soapy water but with a menacing shade of dark grey is what fresh sewage looks like. One pound of solids is present in each 150 gallons of sewage.

Fifty percent of the solids are minerals and the other fifty percent consists of vegetable and animal matter. Decomposition of the vegetable and animal matter component of the effluent gives way to a forty percent suspension that settles in time and a sixty percent solution that does not.

Waste material has portions that decompose and don't and its disposal becomes a major issue in sewage treatment. Sewage is brought to a septic tank which permits the faster decomposition and decay of waste matter. Scum is formed by the lighter parts of sewage plus grease while the solid parts of the waste matter descend to the base of the tank where decay takes place almost immediately.

The action of decomposition is brought about by certain types of bacteria known as aerobic and anaerobic bacteria that thrive in the absence of air. The organic solid component of waste matter is reduced to liquids and gases after the bacteria have acted upon them. Not all of the waste material is digestible so those that remain undigested sink to the bottom and form sludge.

Decomposition cannot take place without the presence of bacteria in the septic tank. Chemicals that are flushed into the tank hinder the decomposing activity of the bacteria. Clearing drains with the use of chemical substances and lye is not advised.

A balanced volume of liquid sewage is always present in the tank because raw sewage pushes an equal amount of liquid out onto the discharge side of the tank. Incoming sewage is diverted towards the base of the tank through a baffle in the inlet.

This allows fresh sewage to decompose in time and not be discharged immediately and also to keep the scum settled. This aim is completed through the help of the baffle at the outlet of the tank.

The effluent that is discharged carries with it a fetid smell even if most of its components have decomposed. Rain water must never be drained into a septic tank. For the average two bedrooms home, a 500 gallon septic tank should be large enough to be satisfactory.

A 1000 gallon tank would be most useful to large houses. A septic tank can produce good results if it is cleaned regularly every three years.