Warning Signs Your Septic Tank is Going to Flood

by Allied / Friday, 10 July 2020 / Published in Flood Restoration, Water Damage

Take care of your septic tank and it will take care of you. Primarily, your wallet. Routine maintenance and services are definitely a fraction (hundreds of dollars) of what repairing a system failure costs (thousands of dollars).

How do you know whether or not your septic tank will flood? It’s not just walking out your front door and doing the tried and true sniff test. Though, like many problems in life, it is true that you can sniff out a septic tank issue if you stick your nose in the right places, so to speak.

Symptoms of problems aren’t always simple or straightforward to look for, here’s where to start.

Septic Tank Failure Warning Signs 

The warning signs of septic tank problems can be sussed out. The Washington State Department of Health recommends checking if:

  • There is back up from toilets, drains, and sinks
  • Baths, showers, and sinks are draining much slower than they normally do
  • Gurgling sounds are coming from the plumbing system
  • There is standing water near the septic tank or drainfield
  • A stink is coming from around the septic tank, drainfield, in the house, or around the yard
  • There is an abnormal presence of spongy, bright green grass over the septic tank at any time, even during the summer or dry weather
  • Grass is growing faster in one particular area of the yard
  • Algal blooms are in nearby water, be it ponds or lakes
  • High levels of nitrates or coliform bacteria are in water wells

Another problem is if there is compacted soil from driving on the drain field.

There are a few reasons as to why those bulleted items could be occurring, but first, let’s discuss how a septic tank works, in order to gather an understanding of the bigger picture.

How Does A Septic Tank Work

Wastewater drains from places in the home in hard pipes through the use of gravity. This wastewater enters the septic tank below. The septic system is generally a watertight container that collects the waste through an inlet from the home and disperses effluent through an effluent filter that keeps solids from entering the drain field (commonly known as a leach field) where water is dispersed.

If solids enter the drain field, the soil could get clogged and the water won’t naturally disperse.

Once wastewater comes from the home to the septic tank, the watertight container holds three layers. At the top is scum, which is oils and grease that are lighter than water. The middle layer, effluent, is wastewater that flows out of the tank through perforated pipes that slowly disperse it into the drain field. The bottom layer is sludge, or solids.

The septic tank (which is generally made from concrete, fiberglass, or polyethylene) separates water from solids in a natural process to treat and dispose of wastewater generated in the home. Though there is some biological breakdown and purification in the septic tank, most of that happens in the drainfield.

That’s a basic overview of the form and function of a septic tank. Its infrastructure has a few weak points.

Some Common Failures in Septic Tanks

Given that pipes from the home drain to the tank below, that could be a symptomatic area to look at, particularly if they’re clogged. This is important in identifying if a septic tank is not flooding. A professional can come “snake the line” or unclog your pipes if solid matter is being disposed of through the drains, which, by the way, don’t do that. 

Similarly, the inlet to the tank could be clogged due to solids just outside the tank in the pipe or a build up of solids in the tank. The effluent filter, mentioned above, could also be clogged by solids in the tank that rise up to it. Annual inspections and filter cleaning is a way to resolve this.

The septic tank could be back-flooded as well. Keep in mind that weather and flooding events can subsequently cause a septic tank flood by oversaturating the drain field, so keep an eye out for this as a warning sign. The water cannot disperse into the field, so as the tank fills up from regular water use, it will likely back up into the home.

“Most septic tanks will not be structurally damaged by flooding since they are below ground. However, flood water may enter your septic tank through a flooded lid or when flooding causes ground water to rise and your tank becomes immersed. In either case, water can enter your home through toilets, showers, or floor drains if the water covering the flooded tank is higher than these openings in your plumbing system,” according to the Independent-Observer in Conrad, Montana.

According to Dr. Andrea Albertin from the University of Florida IFAS Extension, if you open or pump out the tank after flooding occurs, silt or mud can get in and impede drainage, the tank could also try to pop out of the ground.

If your home is experiencing a septic problem it’s best to get it checked as soon as possible to prevent basement flooding. If it’s too late, make sure to have the water damage repaired by an expert and not to try and manage this biohazard yourself.