This is what your septic tank looks like. It's dimensions depend on the number of bedrooms (not bathrooms) in your house. Generally, it measures 8 feet long, 4 feet wide and 5-1/2 feet overall in height (liquid depth 4-1/2 feet).

It can accommodate anywhere from 750 to 1500 gallons, depending on the provincial codes applied by your local municipality.

The material going into the septic tank is divided into three general categories:

The gas is released through the vent system of the house and the liquids ordinarily flow by gravity into the drainage field.
In theory, this process can go on indefinitely if the system is properly maintained. This maintenance will be discussed later.

REMEMBER, THE SEPTIC TANK NORMALLY IS FILLED TO ITS LIQUID TOP LEVEL IN ORDER TO FUNCTION PROPERLY.

A drainage field is a trench or bed excavated just beyond the septic tank to a sufficient depth to provide natural drainage for the effluent (the technical name of the partially treated liquid coming out of the septic tank.) The ability of the ground to accommodate the liquid usually has been determined by running a percolation test at the house site. The results of this test plus the size of the house(again, number of bedrooms) determine the depth and square footage of the drainage field. The septic tank is connected to the drainage field by a pipe at the outlet end of the septic tank. Perforated pipes run the entire length of the drainage field over a bed of filter media (usually rock or coarse sand) having a minimum depth of 12 inches. Poor soil conditions (impervious soil muck, marl or tight rock) could cause the depth of the material to be substantially more than 12 inches.

When impervious soil is present, not allowing the installation of a conventional septic system, there are two alternate solutions available:

Research is constantly being-carried out to discover a more efficient baffle to minimize the amount of minute solid particles allowed into the drainage field.

OVERLOADING

A two-bedroom house is designed for four persons or less. In the case where the family continues to grow, bunk beds are added or a sunroom is converted into an additional bedroom,the system which originally was designed and installed to handle four persons adequately, now is attempting to do the work for more individuals. It will do for awhile, but eventually the system becomes overloaded. This results in a saturated drainage field and a tank that is receiving more solids than it can dispose of.

It must be noted here that the tank itself fills to the inlet and outlet point within just a few days of being put into use. When you stop to consider that the average household of four will use approximately 200 gallons daily in bath and showers, washing machines, cooking and toilet flushing, not to mention the countless other times per day that water is turned on and off, it becomes obvious that the tank fills quickly. An important part of its job is the transfer of these liquids to the drainage field which has a much larger capacity for storage and further treats the effluent by filtration. Increasing the number of people (or waste going into the tank) by as much as 50% over an extended period of time is sufficient to overburden both the tank and the drainage field. A faulty plumbing fixture such as a running toilet, with which you are no doubt familiar, can force hundreds of gallons of wasted water to go through the tank and into the drainage field, thus causing saturation of the earth under the drainage field and complete cessation of function.

WASHING MACHINES

Many residential clothes washing machines are connected to septic tanks. Washing machines are responsible for the highest volume of water going out of your house at one time. Some of the more sophisticated, newer machines discharge as much as 45 gallons at one time compared with a commode flush (three to five gallons). This obviously will have a great effect on your septic tank especially if two or three washes are done consecutively. A continuous deluge of water could create a hazard to the smooth operation of your septic tank system.
How can you use your washing machine and still not overtax your septic tank?
The one thing you can do is to space your washings throughout the week rather than several loads on just one or two days.
Another solution to washing machine heavy surges is the dual septic tank system (one for grey water and one for black water waste).

GREASE

If there is any one factor that causes more trouble in septic tanks and drainage fields, it is grease. For one thing, the type of bacteria that lives, eats and multiplies in septic tanks does not thrive at all in solidified grease. For another, all animal fats congeal or solidify at room temperature. You have no doubt had occasion to leave a pan on a stove temporarily after frying bacon, hamburgers, etc. As soon as the fat remaining in the pan cools, it becomes a grey, solid mass.This very same thing happens when the leftover fat is poured down the sink drain or into the garbage disposal. It begins to congeal in the sewer line on the way to the tank and a major portion of it forms a big solid chunk in the tank. After successive deposits of grease over a period of months, the sewer line passage has become very constricted, if not closed up completely, and the tank now contains a tremendous mass of solid fat which cannot be converted by bacterial action. To make matters worse, the homeowner notices that drainage from within the house is becoming slower. Suspecting that if "pipes are clogged", they use one of the commercial preparations in crystal powder or liquid form with a strong acid base. This treatment may or may not eat a temporary narrow opening in the sewer pipe, but when the strong chemical gets to the tank, it promptly kills what few bacteria are left, attempting to survive on the small amount of sewage not completely wrapped in solid grease. The damage has now become two fold. Chemical action has died in the tank while grease sludge packs the tank, obstructing both the inlet and outlet so that water cannot get into the drainage field, which is ruined by grease, and no new sewage can flow into the tank. To prevent this problem, we suggest the installation of a pre-filter at the exit point of your tank, as well as having it emptied every 2 years.

MAINTENANCE OF YOUR SEPTIC SYSTEM