Once a septic tank is full, it should be emptied, but because a septic tank is below the ground and not visible, it’s hard to tell what you can get away with in terms of usage. Shower water is generally not very dirty and contains soap and nice-smelling liquids. So, in this article, I will explain if you can shower when your septic tank is full.
As a general rule, you should not shower if your septic tank is full. When a septic tank is full with solids, any water that enters the tank will carry the solid into the runoff that goes underground. This causes too much waste to enter the runoff area and can cause nasty smells.
It’s recommended to have a septic tank emptied before it reaches capacity but provided it’s not completely full, it’s OK to keep using it.
Below, I will explain in detail what happens when your septic tank is full, so you can understand why it’s not a good idea to shower if your septic tank is full. I’ll also cover if you can flush a toilet when your septic tank is full and how often, on average, a septic tank needs to be pumped.
What Happens When a Septic Tank Is Full
When a septic tank is full, it’s still possible to use the plumbing in your home. However, it is recommended to have your septic tank emptied sooner rather than later to avoid issues. Here’s what happens when a septic tank gets full.
Overall, the solids will accumulate on the top of the septic tank, and more and more of the solids will get into the soil absorption area. If it’s not emptied, it will form a biomat that clogs this area and causes water to overflow into the soil absorption area. When this happens, it’s expensive to fix.
Taking a shower, using a toilet, doing the laundry, running water down basins, and washing dishes in the sink can still be done when a septic tank is full. But, once you’re aware that your septic tank is full, it’s best to make the least amount of wastewater possible until you have it emptied.
As you may know, with septic tanks, there is a soil absorption area. Which is the area where the wastewater flows and seeps into the soil. These are designed so that they can process wastewater. But not the solids that are meant to settle at the bottom of a septic tank.
When a septic tank is full, the solids accumulate all the way to the top of a septic tank. So, when new wastewater enters the septic tank, it carries the solids and the water into the soil absorption area. Solids take a long time to break down.
According to Penn State University, there are a few different types of solids that will be present in larger or smaller amounts in the wastewater produced from a home. For example, some types of solids, such as toilet paper, break down somewhat quickly. Whereas others, like hair, will virtually never break down.
Although, these do eventually break down. They break down far too slowly for the soil absorption area to handle. As a result, the soil absorption area will get clogged up, and water will begin to pool in the soil.
If the plumbing in a home continues to get used, the water can begin to get seen on the surface of the soil and garden above where the soil absorption area for a septic tank is.
Empty a septic tank sooner rather than later [when and how to check it]
According to Penn State University, a septic tank should be emptied when the amount of solids is 30% of the entire tank. As you may know, a septic tank has a layer of water and a layer of solids. The solids settle to the bottom. It’s possible to test the amount of solids in a septic tank using a long pole.
You insert it into the septic tank. The layer of solids is dark in color, so it will leave a dark color on the poll. You can see roughly how thick the solids layer is. If it’s over about 30%, you should have your septic tank emptied.
Will a Toilet Flush if the Septic Tank Is Full
If you’re aware that your septic tank is full, you should have it emptied immediately. However, it can take a bit of time before a company can send someone out to empty it, and during that time, you may need to use the toilet. So, this is whether it’s OK to flush a toilet when a septic tank is full.
As a general rule, a toilet will flush if a septic tank is full. But it’s best to get a septic tank emptied as soon as possible. When a septic tank is full, the solids will also flow into the soil absorption area, which will cause it to clog. If this happens, it’s expensive to fix.
If your septic tank is full and you flush a toilet with solids in it, it is virtually guaranteed these solids will flow into the soil absorption area. The reason is the septic tank is full of solids. Therefore, the only place the solids can go is into the soil absorption area.
How Often do Septic Tanks Need To Be Pumped
If it stays full for too long, then it can cause issues that are expensive to fix. Therefore, it’s a good idea to know how often, on average, a septic tank should be emptied. So, here’s how often a septic tank should be pumped.
On average, every 2 to 3 years. But, it can be more or less often depending on how many people live in the home a septic tank is attached to and how big or small a septic tank is. Below is a table that shows how often it should be emptied based on how many people use it and how big it is.
This table shows how often a septic tank needs to be emptied. However, it is for the smallest septic tank size – 500 gallons (1900 liters).
| How many people live in the home | How often it needs to be emptied |
| 1 | 6 years |
| 2 | 2.5 years |
| 3 | 1.5 years |
| 4 | 1 year |
| 5 | 1 year |
| 6 | 6 months |
| 7 | 6 months |
Most septic tanks are quite a bit larger, and therefore, for an average family, they will only need to get emptied every 2 to 3 years. There is a helpful table available here from Mr Rooter, where they show how often, on average, a septic tank needs to be emptied based on its size and the number of people that use it.
Amos Christen graduated with a bachelor’s degree in Interior Design from Drexel University — Philadelphia, PA. Since 2003, Amos has worked with top interior design professionals in this area, including architects and interior/graphic/lighting designers. As a skilled interior designer, Amos Christen is highly versed in fine arts and crafts and uses that to supplement his main area of expertise. He often publishes articles related to home décor on several websites, including Sprucetoilets.com, Sprucebathroom.com, and Mybesuitedhome.com. He also contributes to leading interior design magazines.