How to Get Rid of Septic Tank Odor Outside? Causes and Prevention

It might begin with the smell of sewer after the rains. And then, you wake up the next morning to find your entire house smelling like the sewer. Eww!

Perhaps the washing machine stinks?

But no! Ultimately, you find out, the septic tank is the offender.

A well-maintained septic tank isn’t supposed to emit any type of odor. The stink is an indicator that something is amiss.

That means you need to fix the issue without any delay.

How to Get Rid of Septic Tank Odor?

In most cases, septic tank odor is concentrated in four main locations.

• Near the septic tank
• Around the drain field
• Inside the house
• Near the yard

When organic waste is broken down by bacteria inside a septic tank, the various gases are a natural byproduct. However, the design of the septic tank ensures that these gases aren’t released into the atmosphere.

If you’re using a septic tank, you need to have an idea about how the septic system works. So, if there’s an odor from the tank, you can take some corrective measures.

• Check the manhole of the septic tank. Gases can escape from the tank if the manhole lid is loose.
• At times, sticking to the pumping schedule for the tank, may not work. If you suspect that the tank is full, go for scum and sludge level test. This is a DIY process that will tell you if the tank needs to be pumped. Warning: it’s not a pleasant task. 
• The septic tank is designed to hold human waste and toilet paper. Non-organic materials flowing into the septic tank might harm bacterial life. It may lead to the incomplete breakdown of the waste materials. This might also increase the sludge volume that will need more frequent pumping of the tank. You can use dye tracer tablets to check if the system has any such problem.

Other than these, there are a few more steps you can take to fix the issue.

Add Baking Soda

Adding baking soda to the toilet can help in maintaining the right pH level inside the tank. This allows the microorganisms to function best. Cleaners based on bleach and ammonia can be harmful to the bacteria in the system.

A cup of baking soda per week should be good enough. For the best results, add 1/2 cup of vinegar into 1/4 cup of baking soda. Then put two tablespoons of lime juice in it. The mixture is not only good for boosting the bacteria but will also help in cleaning clogged drains.

Beyond that, there are septic tank enzymes and probiotics that can be used to speed up the chemical process inside the tank. 

Jammed Plumbing Vent Stack

One possible reason for the smell is clogging in the vent stack on your roof. This vent helps in maintaining the right air pressure in the plumbing system. It also allows fresh air to enter the system to keep the odors under control. 

If the vent clogs up, it can result in an imbalance in the entire system. And I have seen plenty of vents being clogged by bird nests. Clogging can also be due to debris and dirt.

Sometimes, if your house is in a low-lying area, the vent pipe may not be long enough. Increasing the height of the pipe is the only solution.

If you can access the roof to inspect the pipe, fine. If it’s risky, best take the help of a professional plumber to get the job done.

Problems in the leach field

Blocked pipes in and around the leach field can be a reason behind the smell. If you find the soil to be soggy, or water pooling over the grass, something is wrong.

Take the help of professionals to check the underground pipes in the septic system. You will need to do the necessary repairs to get rid of the smell.

Dried out pipes

Generally, there’s some amount of water that remains trapped in the pipes that connect with the septic tank. These spaces are called P-traps and the water prevents the smells from accessing your toilet system.

If you smell septic odors in the bathroom, this water might have dried up. Check the drains and pipelines to see if they appear dry. If so, pour some water into them. In case there are toilets or sinks that you don’t use, make sure to run them periodically.

Is It Normal to Smell Your Septic Outside?

No, it’s not. If the issue isn’t an overflowing tank or a choked vent pipe, there are other reasons that can be the cause.

Let’s take a look at some of the main ones.

Wrong pH levels

A newly installed septic tank might have the wrong pH. Ideally, the tank should have a pH between 6.8 and 7.6. If the environment is too acidic, the system will malfunction.

In addition, a new system may not have enough bacteria in it. Contact a qualified plumber to check if th problem can be solved by adding biological additives.

Blocked Drains

If the drains that carry the waste into the tank are blocked, the gases will backflow and enter your home. Cleaning up the drains is the only solution in this case.

Note, if you notice clogging in multiple drains in different rooms, the issue isn’t due to a clogged pipe. That means there’s something wrong with the septic system.

On the same note, damaged seals around the toilet or rotted gaskets in pipelines can also be the reason for septic odor. Get the system checked by a professional and replace the necessary components

Heavy Rains

If the rainfall is exceptionally heavy, the groundwater might seep into the tank and cause it to overflow. This may cause the gases to escape from the tank and result in an odor.

This problem can be solved by constructing another drain that can direct the groundwater away from the tank. You’ll need a qualified plumber to get the job done.

Extreme Cold

The septic system can freeze during the winter and the vent pipe can get blocked by snow. Besides, the drains and the leach field can also freeze up. This makes it difficult for the water to percolate in the ground.

Sometimes, the system might smell in winter if you’re not using it for long periods. Reusing the system should solve the problem.

Frequently Asked Questions

Why does my septic tank smell outside?

The septic tank can smell if it’s full or the drains are blocked. Other than that, the vent pipe might be blocked. If these aren’t the reasons, you should consult a professional to check the entire system.

Are septic fumes harmful?

Yes, they are. Exposure to septic gases like hydrogen sulphide, methane, and ammonia can lead to eye irritation, breathing issues, and asphyxiation. However, even if these gases can stink, they aren’t present in dangerous concentrations unless you enter the tank.

How to get rid of septic tank odor in the house?

To get rid of septic tank odor, you need to maintain the chemical system in the tank properly and clean it at regular intervals. Also, check for clogged or dry pipes, blocked vents, and loose manhole lids.