The info on this tank is it was installed when the house was built in 1975. The top of the concrete is just 4 feet away from slab outside my back door and a tree was between the slab and the tank. Why anyone would put a tree that close to a tank or a slab just doesn't make sense. Anyway I had the tree cut down 2 years ago and I've been trying to rot it out. Most of the people I contacted about cutting out the stump wouldn't attempt it that close to the tank. I have someone coming to help me cut away as much of the stump as I can get to. My problem now is the field line is not taking all of the water and the tank is overflowing. I understand the field line could be blocked but that's not really my question.

My question is: Once I've cleared that the tree has not grown into the tank or that the tank is not cracked (I hope) how do I seal the tank properly? Is a concrete tank designed to be airtight? Is that possible or desirable in this case? As far as I know there is only one tank, no idea of the size. The house is a 3 bedroom if that gives you an idea of what size tank would have been installed in '75.

Any advice welcome and thanks. Charlotte

 

Generally the tanks are not air or water tight. They are sealed reasonably well by a tight fitting concrete cap to keep out dirt and debris but there is no gasket to make it truly water or gas tight at the lid. Sealing the tank is not necessary.

 

Have you had the tank pumped? most will evaluate the condition of the tank at that time along with anything else they notice.
Many never give a thought to those things just that it looks nice now, not even considering what will happen later

btw - welcome to the forums!

 

If tree roots have grown into your septic tank piping, cutting the tree down will not eliminate them (and the problems they cause!) Depending on the size and construction of your tank, it may have a top "lid" section (this section has the access holes). That lid is often not sealed , since the seam where it sits on the main part of the tank is above the "waterline". As Mark mentions, once the tank is exposed and pumped, you or the tank pumper should be able to see any problem roots. (It may take a mirror and a good flashlight) Good luck, Steve

 

Thank you all for your replies. I had the tank pumped out a couple of years ago and if my memory is right they said there was 3 "lids" on top of the tank. They only pulled off one in order to pump it out They didn't say anything to me about seeing limbs inside but with the trunk of the tree sitting on top of at least one of those lids I don't think they looked down far enough to see. The only thing I remember them saying was there was some dirt in the bottom and they would not pump that out. When they sat that lid back on the tank they laid a rubber strip down the length of the seam between the lids, I assume to stop more dirt from getting inside, it wasn't a air tight seal just a way to stop dirt from getting in the crack. The lid they pulled off did not require a crane, it was approximately 2 1/2 ft wide by 4 1/2 ft long. They just slid it away and we could see the bottom of the tank when they'd finished. On the side of the tank I could see was the hole leading to the field line, it was not blocked and I could not see any limbs. But the tree sat on the opposite side of the tank and I couldn't see under it.

You've answered my question and I'm glad I don't need to try to create an air tight seal. I'm trying to be positive here so if I find the tree has not grown into the tank and I can clear away enough to ensure it won't grow again, do you have advice on what to do? Do I need to do anything other than put the lid back on properly?

I'm pretty sure my field line is blocked, that tree wasn't the only one they put in the yard. Is there a way to add root killer into a field line?

 

It sounds like your tank is similar to my youngest son's tank. It has 2 removable lids, 1 on each end. Because there was dirt that couldn't be pumped out of the bottom of his tank and believing it came thru the top - I laid tar paper [folded over] across joints. The pumper guy said many use shingles. The newer tanks have a smaller lid that is cut on an angle which helps it to seal better.

They have a machine that can go thru the field lines and cut out the roots but I don't really know anything about it.

 

Thanks marksr. Shingles are a good idea, I'll remember that. I'll contact a septic company and see about clearing the field line. Charlotte