Septic Tank backed up into basement

[Hendu87]

A couple weeks ago we had a really bad rainstorm and my septic tank backed up through the floor drain in my basement. Cost me $2500 to clean... I'd like to make sure this never happens again

We moved into this house about a year ago - never had a septic tank before. It was emptied last May. Any ideas why this might have happened?

My best guess is that we had a river of water running through our back yard - over the covers - and water leaked in that way. Whats the best way to waterproof them? A little Flex Seal(TM)?

Is there some other explanation for this? Or something else I should do to prevent?

Thanks

 

[GoodSheperd]

You should be aware of what type of Septic tank you have ... You can contact the owner to know clearly .Some tanks are of the soak type that allows water to drain away in the soil , but if any source of water is near like a river or a pond , water will fill it from outside .

 

[Hendu87]

You should be aware of what type of Septic tank you have ... You can contact the owner to know clearly .Some tanks are of the soak type that allows water to drain away in the soil , but if any source of water is near like a river or a pond , water will fill it from outside .

Thanks for replying - according to the documents I have it is a concrete aeration tank. After I took a closer look, one of the covers is in very bad shape and definitely not water tight. When hard rain falls and it drains through our backyard I am certain water can enter via these openings. Appreciate any other insight you may have

 

[Diehard]

There could be a number of different reasons for the backup.
Won't hurt to seal the covers better but I would look into installing a backwater valve(a septic system check valve) to help insure no backflow into the house piping.
An easier approach, which may be effective, would be a backflow device in the floor drains to prevent backflow.
Just Google "floor drain backflow devices" and look at the choices available to you.

 

[haloflood]

If the disposal method of the system is located underground (some form of leachfield or lateral lines), then the wastewater going out of the tank into the lateral lines will either drain very slowly or won't drain at all when the soil is saturated with water. Normally the wastewater drains into the soil, but if the soil is already filled with rainwater then the wastewater has nowhere to go except up and back. Regardless, making sure the tank is as watertight as possible will help prevent extra water from entering the system from above ground.

 

[Jeff Handy]

Diehard had a good idea about putting a back flow preventer in the floor drain, kind of a one-way stopper, like a check valve type of drain insert.
The ones I have used have a captive float that rises to seal the drain from below.

But I have sometimes had these things fail, because the water trying to back up is not clean, it’s mixed with TP and poop. Which can block the seal.

There is a more reliable type of backwater valve that is installed in the drain line under the floor, but you would have to bust the floor up for that.

Maybe the pros on here could advise if a standpipe fitted into the floor drain would be legal, or advisable.
After fixing everything outside to try to exclude rain water, of course.