The presence of bad odor is often a sign of a septic system problem.
For the most part, the smell is caused by a full tank.
As such, pumping the tank should take care of the odor problem.
However, there are some cases where you may pump the tank but the odor still lingers.
So, what does that mean and what should you do to remedy the problem?
More of that in a moment but first, let’s understand some basics…
Why A Full Tank May Cause Bad Odors
In an ideal scenario, the anaerobic bacteria in the septic tank will digest and liquefy the solid waste in the septic tank.
Carbon dioxide, methane, and hydrogen sulfide are some of the gases that are released by bacteria as they break down the waste.
Hydrogen sulfide has a strong odor (comparable to the smell of rotten eggs) and is the main reason why tanks may have bad odors.
Strictly speaking, every septic tank that is functioning properly will have bad odors.
Nonetheless, these odors are usually trapped within the tank and will therefore not be noticed.
But as the tank fills up, the gases build up and start escaping the tank and they find their way into the house and the yard.
In such a scenario, emptying the tank is enough to remedy the problem.
However, the smell will not disperse immediately after the tank has been pumped.
It might take a couple of hours for the odor to clear from your house and around the yard.
So, before you panic about the lingering smell, give it a few hours just to ascertain that the problem has not gone away.
What If The Smell Persists After Emptying The Tank?
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If the smell lingers even after the tank has been pumped, then it means the odor was not only being caused by a full tank.
Here are a couple of other issues that may be causing the septic tank odor.
Dry Drains
A septic system typically uses U-shaped pipes which are designed this way to hold gases and water from backing up.
If the septic system remains unused for a prolonged period, the drain pipes may dry up and be clogged up with debris.
If this happens, odors may rise in the pipe and into the home.
If you run water through the drains, the problem should remedy itself.
However, if there was too much debris, water alone may not be sufficient and you may need to use additives or get the help of a plumber.
Vent Stack Clog
Vent stacks are a useful part of the septic system as they help to release excess gases from the system.
Apart from the foul-smelling hydrogen sulfide, flammable gases are also released via the vent and this helps to avert unnecessary accidents like septic tank explosions.
If the vent stack clogs up, the gases may not be vented out and this will cause the odor to remain in and around the house.
Vents are typically clogged up with leaves and other debris and so unblocking them is relatively easy.
As a rule of thumb, always clean your gutters and roof as that will help avoid clogging up the vent.
Cold Weather
Just as the vent can clog up with dry leaves, it can also be clogged up due to ice buildup.
If you live in an area where ice storms are common, a clogged-up vent due to cold weather is highly probable.
The ice buildup will seal the exit and make it impossible for the odors to escape as they usually do and this will cause an odor buildup in your home.
If you live in a region that often gets ice storms, you will want to inspect the vent regularly to ensure it is not blocked.
A little ice on the vent shouldn’t be an issue but you should be worried if it accumulates to the point of sealing the exit.
Defective Seals/Gaskets
A defective seal or gasket on one of your pipes may also cause an odor problem.
Even though defective seals can happen anywhere, the commonest area is around the base of the toilet.
If this is the case, the odor problem will be particularly bad in the bathroom.
Two main problems might be affecting the seal—either the seal has gotten loose or it has rotten.
A loose gasket only needs a toilet wax seal to get it back to normal but a rotten one would need to be replaced.
Whichever the case may be, it might be a good idea to consult a plumber to avoid making the problem worse.
It might also be a good idea to ask the plumber to inspect your entire system to ensure there aren’t any other loose or rotten seals.
Broken Pump
Another reason why septic odor may persist even after pumping the tank is a broken pump.
Septic systems may have a pump that helps in moving wastewater from the tank to the drain field area.
If the pump wears outs, it may no longer be efficient especially as the needs of the household grow over time.
You may need the help of a plumber or a septic tank professional to help you diagnose any issues with your pump.