Do Septic Tanks/Systems Leak?

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Do Septic Tanks Leak?

Perhaps you’ve noticed sewage seeping out and contaminating your soil. Or perhaps you are noticing slow drains and flushing, especially in rainy weather. These are highly undesirable situations to be in and they could be indications of problems with leaks in your septic tank system. A number of the causes of septic tank leaks may be undetectable until the problem has turned severe.

Do septic tanks leak? Any septic tank can develop a leak either out of the septic tank if there is a hole (due to rust corrosion) or if there is damage (for concrete, fiberglass, or plastic tanks). A septic tank with a leak results to effluent that is not properly treated because it is not reaching the drainfield. Also, leaks into the septic tank is possible whenever there is any opening that allows surface runoff water to enter the septic tank. This risks flooding the tank, reducing its ability to treat sewage.

As soon as you notice sewage backup, slow drains, and/or foul odor from your yard where the septic system is situated, you will want to check on two areas for leaks immediately: the sewer line entering your septic tank, or the effluent outlet leaving the septic tank. There is a likelihood that the pipe is not sealed suitably in those locations. Modern septic tanks may include a rubber gasket that helps seal the tank’s inlet and outlet openings. But note that if the sewage lines entering or the effluent lines exiting the septic tank are at sharp angles respective to the tank, your septic gasket may not be fixed well in place.

You will also want to check for any damaged sewer piping or effluent piping that could be permitting groundwater or surface runoff to flow into the septic tank or into your drainfield.


Also, if what you have is a steel septic tank, you should check for rust corrosion. Rust damage can allow effluent out of the tank and surface water to leak into your tank, especially in heavy rainfall.

If what you have is concrete, fiberglass, or plastic septic tank, you will want to check for cracks. Cracks or any other damage on the body can allow effluent to leak out of the tank or water to leak into it.

Signs of a Possible Septic Tank Leak or Damage

Foul Odor. Sewage gas and sewage water stench can come from a septic tank lid that is out of position or that is damaged. If your septic tank body has a hole, is cracked, or deteriorated, gaseous odors may escape and will last over a long period of time. Damage is potentially where are the odors are the strongest. So check near your tank, drainfield, or even from your near neighbor’s septic system, if close enough.

Lush vegetation. Especially lush grass or flowerbed over your septic system can be an indication of a leaking septic tank. This may also be caused by a septic system that’s overflowing or a pipe running to or from the tank that has come loose or has been damaged. A wet soggy area over your septic tank may indicate a clogged effluent filter or clogged drainfield.

Stagnant water. Soil tends to compact when exposed to extended wet conditions. If a septic tank has a leak, the water leaking out could cause the soil in your septic tank area to settle and drop. This allows surface water from the rains or your sprinkler systems to create puddles. Take note, however, that odor or stagnantly wet areas may not be from a damaged or leaking septic tank. You should likewise check your sewer lines near the tank for cracks or damage because the sewer waste may be the cause of the problem. Sewer lines are typically situated in a trench coming from your house of facility going to the tank. If there is a leak in your sewer lines, the trench itself could be allowing the wastewater to migrate toward the septic tank.

Backed-up or slow-draining toilets or sinks. These can be indications of septic tank damage. Check for growing tree roots that may be blocking or damaging the area where the effluent leaves the tank. Before actually pumping and inspecting your septic tank, know that some experts recommend that you video the sewer line coming from the house or establishment to the tank. This is so you can view if the line is cracked, clogged, off-post or has collapsed.

Unseen Causes of Septic Tank Leaks

Damaged Baffle. If one of your septic tank’s baffles is damaged, this can cause a hole that allows water from the septic tank to escape through. This is possible when a concrete baffle corrodes due to the gaseous matter in the tank, or if the baffle was not sealed to the inlet or outlet pipe properly, or if the baffle detaches somehow.

Crushed Pipe. Check your inlet and outlet pipes and ensure that they are securely attached to the septic tank. Pipes can become damaged near or exactly at its connection to the baffle, typically from heavy machinery or vehicle being driven over the septic spot. Even your septic tank itself can become damaged and develop a leak due to the weight of driving over this area. Take note, too, that driving over your septic tank could cause it to collapse.

Corrosion. Regardless of the type of septic tank you have, it could be susceptible to natural corrosion due to rust, weather-aggravated damage, or from the acidic gas inside the tank. The concrete in septic tanks can also crack from pressure or from improper installation. It is important to know what material your septic tank is made of. Steel septic tanks have a relatively shorter lifespan, as these are more susceptible to rust corrosion and eventual collapse. Collapsed septic tanks can create sinkholes and will definitely require total replacement.

Tree Roots. As good as trees are for the environment, they can actually cause problems when growing too close to your septic tank system. Besides that raw sewage is high in nitrogen that it can burn the tree’s roots, very robust trees can keep on growing roots that can get into your septic tank. It is possible that high levels of wastewater dilutes the sewage and actually “nourishes” the tree roots to grow and get inside your septic tank, opening up or aggravating an already-existing leak. Often, tree roots enter the septic tank through the seal around the tank lid, through damaged inlet and outlet pipes, or through compromised baffles.

Unfortunately, since all these causes occur beneath the ground, you often won’t be able to tell what’s happening until problems present or until you actually have the system dug up or initiate a video line inspection. If you have trees in your property, you should be vigilant as trees’ roots can have a surprisingly enormous reach and you may not realize that they can reach any part of your septic system from where they stand.

Can Septic Tanks be Repaired?

When sewage is backed-up or you start to notice overwhelming foul odors in your yard, you know there is a problem with your septic system. Depending on what’s causing the actual problem, the main thing is you’ll be needing to make decisions about whether to repair your septic system or replace it entirely.

If the septic problem is caused by a broken pipe, patching the damage might cost you just a few hundred dollars. But if your drainfield needs to be replaced, prepare to shell out about $2,000 to $10,000. The worst case scenario is that you need an alternative treatment system, and this rings to a bill of around $15,000, minimum.

Some septic system problems can be solved pretty easily. Stagnant water or sewage odor between the septic tank and the drainfield may be indicative of nothing worse than a broken pipe.
If what you have is an advanced treatment system, it is possible that your septic maintenance company will need to adjust or replace a part.

If you have an aerobic treatment unit (where aeration helps break down the waste) and were away over a long period of time, it could happen that the beneficial bacteria inside your septic tank might have died off. In this case, you will just have to use your septic system sparingly for the next few weeks and allow the bacteria population to replenish.

Visit the websites of your local health department and state environmental agency and learn if there are applicable provisions or restrictions to comply with on the procedures you need done in repairing or replacing your septic system. You may even find a reference of accredited and licensed septic system maintenance providers.

Contact a couple of septic system maintenance providers and schedule consultations. If what you have is an advanced treatment system that comes with an annual maintenance contract, get in touch with the company that’s overseeing your system and schedule routine checks or maintenance.

The difficulty is that there usually are no easy-to-spot indications of a leaking septic tank. The reality is most home or business owners will not know that there is a leak in their septic tank unless they have it opened and pumped out. Regular maintenance of the whole septic system is perhaps one of the best investments any home or business owner can make for their property. Routine and religious maintenance will certainly save you from the inconvenience and worry of very expensive emergency septic system repairs. 



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