Garbage Disposal with Septic

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A septic system is a crucial disposal system that allows for the return of wastewater and its accompanying microbes and nutrients back to the soil. On the other hand, garbage disposal is an appliance created to ease the disposal of solid scraps of food and food waste.

Now, on the surface, it might seem like a garbage disposal with a septic tank is the perfect combination for efficient mess-free disposal but is it? Though the  garbage disposal Trusted Source Garbage disposal unit - Wikipedia garbage disposal unit (also known as a waste disposal unitgarbage disposergarburator etc.) is a device, usually electrically powered, installed under a kitchen sink between the sink’s drain and the trap. The disposal unit shreds food waste into pieces small enough—generally less than 2 mm (0.079 in)—to pass through plumbing.  helps to aid the disposal of kitchen waste, some of the solid materials that would be dumped into it are either not degradable or take too long to degrade. As such, these materials settle to the bottom of the tank and form sludge.

This sludge constitutes one of the problems associated with the use of garbage disposal, and it is these problems and their potential solutions that necessitate the writing of this article.

How do garbage disposals work?

Garbage Disposal with Septic

Garbage disposal has become a highly indispensable appliance in every modern kitchen. Long gone are when scrap food and certain waste constituted a nuisance as this machine has made it easier to keep a clean kitchen. But, how exactly does a garbage disposal work?

The garbage disposal is usually fitted under the kitchen sink in such a way that it collects scrap food and food waste in its grinding chamber. After the accumulation of enough waste and the garbage disposal is turned on, a spinning disc or an impeller plate (possessing a pair of blunt metal teeth) turns at high speed. It causes the food waste to accumulate to be mashed against the walls of the grinding chamber.

During this mashing process, the food materials are crushed into tiny bits that are more suitable for disposal. These little bits are thereafter washed by running water through holes in the walls of the grinding chamber.

The use of this machine has many advantages, and some of these are:

  • It prevents the spreading of unpleasant smells that are associated with rotten foods.
  • Prevents the clogging of drainage pipes that may result from large food particles being unable to pass.
  • It helps the environment by reducing the amount of garbage bags used in waste disposal, reducing the amount of plastic material that would have ended up in landfills.

Things to never put or run through a regular garbage disposal

Despite the garbage disposal being utilized as an appliance for the easy disposal of waste food, not all food scraps are suitable for disposal to act on. This means that the garbage disposal while being functional, should not be mistaken for or used as a trash can.

Most of the foods and materials that are best left out of the garbage disposal are so classified because of their ability to cause jamming or clogging of the appliance and their inability to degrade once within a septic system correctly. This inability to degrade quickly enough is a big deal and could have significantly pronounced effects on the longevity and maintenance costs of using a septic tank.

Some of the best left out of the garbage disposal include meat bones, greases, and oils, fibrous food, potato peels, fruit pits, etc. The list goes on, and the best method to avoid putting in the wrong types of waste is to check that food that absorbs and expands in water has the ability to wrap itself around the blades or get between the teeth of the grinders are left out.

Features to consider in the purchase of a garbage disposal

Garbage Disposal with Septic

Buying garbage disposal is one thing, but getting one that fits the way you like to work or conduct your cleaning is another. To achieve this compatibility between your system of cleaning and effective function, here are a couple of features to look out for in garbage disposal:

The type of motor it utilizes

There are two types of motors used in garbage disposals; the induction motor and the permanent magnet motor. The permanent magnet motor is the more recent of the two technologies and is widely considered more effective. This is because it possesses almost twice the speed of performance demonstrated by induction motors. This would mean that the disposals powered by the permanent magnet motor would use less water and less electricity than the induction motor garbage disposals.

The type of feed mechanism

The feed mechanism of the garbage disposal could be batch feed or continuous feed. The suitability of any of these mechanisms depends solely on the person using the appliance. The batch feed, as the name suggests, allows for the disposal to grind food waste in batches, and while a batch is being worked upon, the device is required to be closed to prevent the addition of more waste. On the other hand, the continuous feed system allows you to keep adding waste to the grinding chamber even while the appliance works. Such disposal can keep working until it is switched off, unlike those with a batch feed mechanism.

The material used in making the mount

The material used in making the mount of the garbage disposal would determine how much noise the disposal would make while working, along with the regularity with which it would need to be changed or maintained. To be more specific, purchasing a mount made of sturdy material like metal would result in minimal wear and tear or the need for regular replacement. It would also result in less vibration and, consequently, less noise. If, however, you decide on garbage disposal with a plastic mount, the cost of the disposal is likely to be lesser, there would be little to no change in the appliance’s effectiveness, but the noise produced would be more compared to those made with metal mounts.

The power of the motor

Another big feature to take note of is the power. Different garbage disposals are made with different power requirements depending on the regularity with which they are to be used or just how extensive their functions would be required to be. The number of users can also affect the frequency of usage, and so it can also be used as a criterion in determining the power rating that is needed. The three classifications for garbage disposal according to power ratings are light use (1/3 HP), medium use (1/2 and 3/4HP), and heavy use (1HP). The models should be adequate for a maximum of 2, 4, and 6 users, respectively, with the heavy use model being the strongest and indicated to be capable of handling most types of food scraps.

The number of grinding stages

The garbage disposal function is to grind food into small particles to aid their efficient disposal. To better perform this primary function, some garbage disposal possesses more than one grinding stage, with some even having up to three. The number of stages would imply that the food would be ground down to even finer particles, reducing the chances that drains could be clogged by food waste. Sue to this classification, the more powerful garbage disposals have multi-grind stages and use two or three grinding stages, while the less powerful models possess just one grinding stage. The type to purchase would depend on the kind of food waste that would be passed through; if you anticipate that you might need to deal with many types of food and some might be on the hard side, a multi-grind stage garbage disposal would better serve you.

The size of the appliance

The size of the garbage disposal to be purchased would depend on the size of the space beneath the sink and whether or not the garbage disposal would fit. As such, the size of your garbage disposal might also require you to compromise on certain features you might have fancied and change certain cleaning habits. Based on this, it is to be expected that deep sinks, such as a farmhouse sink, would require a smaller garbage disposal unit that is more compatible with its design.

A dishwasher inlet

Not all garbage disposals possess an inlet to facilitate a connection to a dishwasher, but they must do. This is to allow for the dishwasher to be used with the garbage disposal due to the likelihood of food particles being washed out along with the wastewater from a dishwasher. This inlet is usually plugged with a cover that needs to be removed before the connection can be made.


A warranty protects the client in the purchase of an item. It guarantees that in the event of a fault, the appliance bought can be replaced or repaired at no extra cost provided that the warranty period has not been exceeded. This is usually an important feature to note in the purchase of appliances, and the garbage disposal is no different. Different models would have different warranties, which should factor in your decision to leave you better protected. Some manufacturers offer a warranty of a few years, while some might even offer limited lifetime warranties.

How do septic systems work?

Garbage Disposal with Septic

Many modern cities possess a centralized sewer system that allows for the efficient management of human waste on a huge scale. However, in the absence of such a centralized system, as is seen in many rural areas, many people make use of septic systems, which are underground wastewater treatment structures that cater to the needs of a significantly smaller group of people.

A typical septic system would consist of a septic tank and soil absorption or drain field. The tank contains microbes that action and degrade organic matter, separating the wastewater from the solid material. If a spoil-based system is being operated, While this solid material settles to the bottom of the tank, the wastewater would be released into a network of perforated pipes that have been buried underground in units that enable the slow release of their liquid load into the soil.

Other septic systems commonly use pumps or a gravity-based system to aid the release of the wastewater through sand, organic matter, constructed wastelands, and other media. During this downward movement of the wastewater, the media pointed out above would neutralize pollutants such as nitrogen, phosphorus, disease-causing pathogens, and other contaminants.

There also exist less popular systems that eliminate the wastewater by evaporating them or, at least, disinfecting them before they are released into the soil. The specific mechanism by which a home septic system operates is detailed below:

  1. All wastewater accumulated in the bathrooms and kitchens of the house passes out from the main drainage pipe into the septic tank.
  2. The septic tank, which is a watertight structure made of fiberglass, concrete, of polyethylene. Its job in the system is to allow for the solid waste to settle, leaving the wastewater on top. Oils and grease also float to the top and are observed as scum.
  3. The wastewater accumulated is released into the drain field. This drain field is a covered excavation made in unsaturated soil, and it is into this excavation that the pretreated wastewater is discharged via perforated pipes.
  4. The wastewater filters through the soil and is dispersed deep into the soil as groundwater. During this dispersal and percolation into the soil, the bacteria, viruses, and nutrients within the wastewater are removed naturally.

Septic system vs. sewer lines

Many homeowners do not have much choice in the selection of whether or not their home should utilize a septic system or should be connected to a centralized sewer line. This is especially true of cities with a developed sewer system. However, if a choice could be made, a well-informed decision should be made.

For one, being connected to the centralized sewer system or sewer lines would eliminate the need to pay a monthly wastewater fee. Also, the sewer lines are less prone to clogging, and though it is advised that, regardless of the system employed, one should avoid flushing certain items down their drains, sewer lines can take way more abuse than septic tanks. More advantageous to the bank statement is that maintenance, spillage clearance, or pumping costs that might accrue from the use of a septic tank are avoided.

On the other hand, is the septic tank. Though they might require more maintenance and more financial effort from the homeowner, they save energy and reduce the carbon footprint as they do not pump wastewater over long distances for treatment in special water treatment plants as is done with the sewer lines. Other than that, using a septic system rather than the sewer lines negates the need for dependence on municipal sewage systems. As such, any disruption within the sewer lines would be of no concern to a household using a septic system. Furthermore, there would be no need to pay a monthly fee or sewage management.

Can you use a garbage disposal with a septic tank?

Regular garbage disposals are widely alleged not to be suitable for use with a septic tank Trusted Source SAGE Journals: Your gateway to world-class journal research Subscription and open access journals from SAGE Publishing, the world’s leading independent academic publisher. , but specialized garbage disposals designed to counter this disadvantage are being made.

We have established that certain food waste that, even after passing through a regular garbage disposal, would not be broken down as efficiently as the human waste that septic tanks are made for. As a result, the solid materials would settle and accumulate much faster, putting a strain on your septic system and requiring your septic tank to be pumped out more frequently than normal. To avoid the extra costs associated with pumping out and maintaining a septic tank and system, it is best to know how to use your garbage disposal with your septic system.

The last statement implies that the garbage disposal can be used with a septic system, and it also points out that this would require some adaptations on your part. Some garbage disposals are being manufactured to possess specifications that make them less damaging to use with a septic tank. In some cases, people are starting to consider alternatives to the use of garbage disposals.

Specialized garbage disposals designed and manufactured for use with a septic system are referred to as septic assist garbage disposals. They are produced with a need to facilitate the degradation of the slow-decomposing food material that settles. This is to slow down and, if possible, prevent the accumulation of sludge-forming solid and greasy materials.

To achieve this, the septic assist garbage disposal discharges an enzyme while grinding the food waste. This enzyme is contained within a cartridge, connected to the grinding chamber, and is used to aid the degradation of the solid food waste within the septic tank. One of such garbage disposals that come highly recommended by experts is the InSinkErator Evolution Septic Assist 3/4 HP Household Garbage Disposal.

As expected, the enzymes within the cartridge don’t last forever, and when it finishes, it can be replaced. For instance, the above-recommended septic assists garbage disposal uses the InSinkErator CG Evolution Septic Assist Bio Charge Replacement Cartridge when such a replacement is necessary.

Alternative to the use of a garbage disposal

If you are utilizing a septic system, the use of garbage disposal (even the septic assist garbage disposals) might be too much of a risk to the safety, longevity and effectiveness of your system. All of this might also lead to you running up bills for repair work and the pumping of your septic tank. As such, rather than put pressure on your septic system and consequently your pocket, why not consider other alternatives to the use of garbage disposal.

One of such alternatives is composting. This is more than an alternative to many people as it also represents an environmentally friendly strategy to the problem of waste control. More attractive to a mother running a family is the ease with which it can be performed or utilized. The use of composting in managing food waste could also benefit your garden or lawn if you have one, and it could be further used to manage paper and other carbon-based waste also.

Composting can also be done in various ways, and you could read up on it to help you start up your operation. To facilitate the collection of the food and paper waste for compost formation, you could use your garbage disposal provided it isn’t connected to the drainage system or septic tank, but seeing as the effectiveness of the garbage disposal in such a situation is to be reduced, and an under sink trash can would serve the purpose just right. The trash can is easier to empty into compost bins at intervals or when it is filled up.

Final thoughts

The use of garbage disposal with a septic system is not advised in many situations because it puts too much of a strain on the septic system, and trying to adapt the machine’s usage not to put much of a strain would be too much work.

Despite this, some garbage disposals are still designed to be quite helpful without possessing this disadvantage. The best garbage disposals for septic systems have been specially designed to deal with solid food waste.

This has been achieved by manufacturers who have come up with new garbage disposals labeled ‘septic assist’ because they provide extra enzymes to aid in the degradation of the food waste passed through the garbage disposal.


Garbage disposal unit - Wikipedia
garbage disposal unit (also known as a waste disposal unitgarbage disposergarburator etc.) is a device, usually electrically powered, installed under a kitchen sink between the sink’s drain and the trap. The disposal unit shreds food waste into pieces small enough—generally less than 2 mm (0.079 in)—to pass through plumbing.
SAGE Journals: Your gateway to world-class journal research
Subscription and open access journals from SAGE Publishing, the world’s leading independent academic publisher.

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