Septic Tank Cracks 101

Septic tanks are typically made of concrete. For this reason, they are quite durable and damage-resistant, but they aren't completely immune to cracking. Knowing how to spot a crack as well as how they are caused can help you spot problems as soon as they arise.

Symptoms

There aren't always immediate symptoms of a crack, especially if the crack is initially small. Some symptoms can also simply indicate that it is time to pump the tank.

1. Lush Grass

Lush, green grass over the top of the septic tank but nowhere else can indicate a leak of some sort. Tanks that are overfilled will sometimes leach some sewage into the soil and cause greener grass. If you have recently pumped your tank, though, a crack could be the problem.

2. Sewage Odors

You shouldn't smell raw sewage near the septic tank. If you're picking up this odor, then sewage could be leaching out through a crack in the tank.

3. Standing Water

Standing water, especially if it smells bad, over the tank location means raw sewage is somehow leaking out. You will need an inspection to determine if this is due to a large crack, overfilled tank, or failed sewer line.

Causes

Sometimes cracking occurs simply because of age, but not always.

1. Vehicular Damage

A likely cause of a septic crack, particularly for tanks that are accessible by vehicle, is that it was driven over or parked upon. A septic field may look like a good open place for additional parking, but the weight of the vehicles puts stress on the tank. This stress will eventually cause it to crack.

2. Soil Expansion

When the soil around the tank contains a lot of clay, it is more prone to expanding and contracting due to moisture changes. soils of this type are called expansive soils, and steps must be taken to protect the tank from expansion at the time of installation. The soil pressure caused by the expansion can lead to a crack in the concrete tank.

3. Concrete Failure

In some cases, the issues can be with the concrete itself. Concrete mixes must be done in the right ratio and cured properly before the tank is fully installed. Cracks due to concrete failure can affect newer tanks, such as those installed within the last few years. With luck, the tank will still be under warranty if it cracks due to concrete failure.

Contact a septic tank repair service if you suspect a crack in your tank.

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