If you live in a city, you may not have heard about septic tanks. A septic tank is the main component in a septic system. A septic system is a small standalone sewage treatment system. Septic systems are used in areas without any main sewer system run by the local authorities or a private company. Septic systems are common outside densely populated areas. In most cities, the use of septic tanks is very rare.
Most septic tanks are very simple, without any moving parts. But a septic system requires on-going maintenance anyway. A septic tank is generally fairly large, a few thousand liters, and has one input pipe through which the household waste enters. On the other side of the tank is the outlet pipe through which the relatively clean water flows to leaching field. The soil purifies the waste water before it reaches the groundwater. In some places, local regulations dictate the required size of the septic tank, often based on the number of bedrooms. Note that local regulations may also dictate how often the septic tank has to be emptied. Septic tanks are made of concrete, fiberglass or polyethylene. Modern tanks typically have two compartments, which makes it harder for the sludge to reach the drain field.
At the top of the septic tank, you have the scum layer which is made up of oil and grease. If the scum layer gets to thick the grease and oil start to flow out of the tank, damaging the leaching field.
The solid waste settles at the bottom of the septic tank, creating the sludge layer. There it is broken down through natural anaerobic processes. Not all solids can be broken down, the tank needs to be drained before the solid waste overflows it. How often the septic tank needs to be emptied depends on a lot of factors. Some of the factors you can control, for example how much and what kind of waste that goes into the septic tank.
A properly designed septic tank will last for decades, as long as it is regularly emptied, without any need of adding any stimulator or enhancer. By inspecting the septic tank every year, you can make sure that the tank is pump before the scum or sludge layer grows too large.
So can you use a garbage disposal with a septic tank? Unfortunately, the question is not easy to answer. A waste disposer will put an additional strain on the septic tank. But how much is impossible to say, it depends on how much and what you feed the disposer. If your septic tank is properly sized, you may not notice any significant difference. If on the other hand, you are already pushing the limits of your septic tank, a garbage disposer may push it over the limit.
Some people say that after starting to use a garbage disposer, they have to empty their septic tank much more often, while others say that they have not noticed any difference. But by limiting the amount of fat and oil you pour into the disposer, you limit the growth of the scum layer in the septic tank. The use of a garbage disposer will also increase the size of the sludge layer. By limiting the amount of food waste that takes a long time to break down, you limit the growth of the sludge layer.
Regardless if you have a garbage disposal or not, you need to be careful what things that go into the septic tank. And be careful not overloading the septic system. Using too much water at the same time can make the water go through the tank too quickly. Put paper, tissues, tampons, dental floss into the trash, not down the toilet. Don’t waste water and use small amounts of soap, shampoo and detergents.