I bought a new house in July and this is my first experience with a septic sysyem. I'm hoping somebody can give the some insight into the most likely cause of the periodic drain back-ups we have been experiencing. Most of the time, everything seems to drain just fine. No slow draining sinks, tubs or toilets (although there does seem to be some minor "gurgling" at times). Yet 3 times since July, we have had waste water coming up through the garage floor drain, the laundry room floor drain and the floor-level shower drain. It's a 40 year old, three full bath house, but there are only 4 people in the family, so I can't imagine that our water usage is excessive. The water stands until we we can get a plumber in to snake. At first we assumed that it was a simple clog, but now the plumber says something must definately be wrong. There are no signs problems outside around the septic tank area (no dampness, smells or especially green grass). The plumber says we probably need to hve the tank pumped out, but that was supposedly done just 6 months before I bought the home. Any ideas ?

 

I would have the septic tank pumped. I would not rely on "supposedly pumped". When the tank is pumped the pumper will be able to tell you the size of the tank and by what is seen in there can give you some idea as to the condition of the system. It will also let you know for certain that the tank was pumped.

40 years ago systems were generally sized much smaller than today's standards and it could have had problems before you bought the house (possibly the tank was pumped just before the house was sold). Just in case I would start setting some money aside just in case.

If the plumber is able to get things working again by snaking your drain lines then it might just be a broken pipe or tree roots (not a failed septic system). You might only need a new drain line/pipe from the house to the septic tank which is much less expensive than a new septic system.

 

I would also definitely have it pumped and checked out by a septic pro. You could have something wrong with your drain field (IE not draining)

 

Scope (using a camera) the line to the system,that will definitely tell you whats going on. Also,a 40 year old house may have a Cesspool,not a Septic tank. Cespools are much more temperamental. I have one,but thank fully it still works okay. And it`s around 90 years old too.

 

A septic tank and drain field are sized on the number of bedrooms and the number of people who are expected to live there.

As you have an intermittent fault, it is likely that it is down to rain.

The ground is getting soaked, the water table is rising and the waste water is not getting away.

Is this what is happening? Heavy rain, followed by slow draining?

It is also possible that too many people are using the drain field? Or too much waste water from washing?

Drain fields are sized according to the national average usage, are you using more?