Garbage disposals can be an extremely useful addition to your kitchen as they make it easy to get rid of some food scraps and waste without needing to toss them in the trash. When used properly, a garbage disposal can also help to prevent your kitchen sink and drain pipe from getting clogged by chopping up any food scraps into extremely small pieces. However, you may want to think twice about having a garbage disposal installed if your home isn’t connected to a municipal sewer system and instead has a septic system. While you definitely can use a garbage disposal with a septic system, you should be aware that it can negatively impact your septic system and potentially lead to higher septic pumping, maintenance, and repair costs.

How a Garbage Disposal Can Impact the Effectiveness of Your Septic System

Septic systems work most effectively when the only things you put in them are wastewater, toilet paper, and human waste. Occasionally washing small bits of food scraps down the drain is normally not that big of an issue, but putting lots of food and other solids down the drain can definitely have a negative impact on a septic system and how effectively it functions. To understand why this is, it’s necessary to know a bit more about how septic systems function and how they break down solid waste.

All of the water and waste in a septic tank is always separated into four layers. The bottom layer consists of a thick sludge that forms when the bacteria in the tank break down all of the solids. Whenever new solid waste and wastewater enter the tank, the solids sink down and settle on top of the sludge layer while the water remains on top. At the very top is a scum layer, which consists of things like fat, grease, and oil that always float on top of the water.

The water inside the septic tank is always high enough that any new waste and water entering the tank pushes some water out of the far end of the tank where it then flows out into the drain or leach field. However, all of the scum always remains inside the tank since the outlet baffle is slightly below the top of the water level. When new wastewater enters the tank, it pushes some water up the outlet pipe and out of the baffle.

The bacteria in the septic tank are the more important part of the system as it works to quickly break the solids down into a sludge so that they take up much less room. This is important as, otherwise, the solid layer would build up much faster to the point that you would need to pump the tank out quite often. The bacteria are extremely effective at breaking down toilet paper and human waste. However, it takes far longer to break down other solids, including food and other paper products, and some things won’t ever break down fully.

The more solids other than toilet paper and feces that you put in a septic system, the quicker the tank will start to fill up and the more frequently you’ll need to have your septic tank pumped out. When you’re using a septic system properly and not putting lots of other solids into the system, you should typically only need to have the tank pumped approximately every three to five years, depending on how many people regularly use your plumbing. If you have a garbage disposal and put lots of food down the drain every day, you could end up needing to have your septic tank pumped as often as every year or more frequently.

How Garbage Disposals Can Cause Septic Issues

Putting lots of additional solid waste into your septic system by using a garbage disposal can also cause a number of issues and potentially lead to costly repairs. Again, the only way to really avoid this is to have the tank pumped out more often. If you don’t have the tank pumped out often enough, the sludge and solids can build up to the point where they reach the outlet baffle. This can be a serious issue as it can lead to solids clogging the outlet or flowing out into the pipes in the drain field.

If the outlet becomes clogged, water obviously will no longer be able to drain out of the tank into the drain field. This can eventually lead to the tank overflowing and sewage starting to leak out into the surrounding area. A clogged septic tank will also cause sewage to back up inside the home and flow out of your shower drains and possibly even your toilets. A sewage backup is obviously a serious issue as not only can it cause extensive water damage, but it can also fill your home with potentially dangerous pathogens.

Having solids flow out of the tank into the drain field can be an even bigger issue. The drain field has a series of perforated pipes buried underneath the ground. When water flows into the drain field, it slowly seeps out of the perforations and into the soil where microbes then treat the water and break down any remaining waste. If you have solids flow into the drain field, they can clog up the perforations so that water seeps out of the pipe far more slowly or potentially make it so that the water can’t flow out of the pipe at all. Again, this will lead to the water level in the tank rising to the point where both the tank can overflow and sewage can start backing up inside your house.

If the drain field pipes do become clogged, your septic system will cease to function and you’ll usually end up having sewage backing up in your home every time you use your plumbing. Unfortunately, the only solution in this situation is to completely dig up and replace the entire drain field. Replacing a drain field is a time-consuming and expensive process and will usually end up costing you somewhere between $1,000 and $6,000 on average. As such, it is definitely something you will want to avoid at all costs.

It’s your choice whether you feel the convenience of having a garbage disposal outweighs the additional costs and potential risks to your septic system. You can definitely use a garbage disposal with a septic system without any issues. However, you should always be extra careful about what types of food you put into the disposal and also make sure that you have your septic tank pumped out often enough that it doesn’t overflow.

At Wyman Plumbing & Mechanical, we’re your top choice if you need any plumbing services in the Phoenix area. Our licensed plumbers specialize in all types of plumbing installations and repairs, and we also offer professional drain cleaning and sewer services. Contact us today if you need to schedule a service call or if you have any questions.

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