# Magnolia tree + septic tank question/problem



## Jemo (Dec 24, 2006)

I wasn't sure which forum to post this question....

We just bought a house that has two septic tanks. Thanks to this forum, I had it inspected and the guy said everything was fine except it was long overdue for a cleaning. The only thing he was puzzled by was that the tanks didn't have an access plug. He had to pry the whole lid up and over in order to empty it. (I think he said it was 3-4" thick concrete)

The tank in the back of the house was not inspected but he said that everything indicated that it was fine. The reason he couldn't inspect it or have it emptied is because some person planted a magnolia tree squarely on top of the concrete septic tank. 

It's a beautiful tree and now at least 25 ft tall. He said that he'd definitely cut it down because the weight of the tree would eventually crush the tank plus I obviously can't empty it because there is no access plug and the whole lid can't be pushed out of the way.

Other people say that there is no way the weight of the tree would crush the tank because the weight is displaced through the roots.

Would you (a) cut the tree down or (b) dig around and see if I can drill an access hole in the concrete lid and try to empty it and leave the tree in place?

What kind of tool do I rent to drill a 8" plug into the concrete lid?

Jeff


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## esel (Jan 5, 2007)

Sounds like someone had trouble with the old tank and installed a replacement. You didn't say how much capacity was required for your house. Many people cover over the access clean-out lid. Some old tanks have a short section of lid that goes across the whole tank but can be slid over to allow for pumping but again,people cover these over and it makes it difficult to access for clean out. I suggest you uncover the whole top of the tank,find your access point and put a riser on it for future clean out. Most tanks I'm aware of are only down about 2' as a rule


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## sheeter (Jan 14, 2007)

You pose an interesting question. I have never seen a septic tank that didn't have a removable lid on the top. Most septic systems use a septic tank, 1,500 gallon for a typical two bath house, and a distribution box that the leech field runs off of. The distribution boxes are usually about a 100 gallon size with 2 or 3 lines running out into the yard. The actual septic tank is usually located within 12' to 15' of the house. If this is the approximate location of the magnolia tree, then you may want to consider moving it, which is a bit pricey. I've seen magnolia trees grow to 50' tall and 30' in diameter here in North Carolina. Would you want that up against your house? Keep investigating the situation, drilling an 8" hole will be extremely difficult, requiring the use of a core drill. You can rent core drills and core bits, but that can be pricey as well. I honestly would weigh the factors involved; IE: the potential size of the tree, the cost to have it moved, the cost to drill an access hole, and the cost of buying and planting a new magnolia tree.


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## Jemo (Dec 24, 2006)

Thanks for your help on this. I think I'll just have the tree cut down because it is pretty close to the house and I forgot how big they get! 

I forgot the capacity of the tank but there is one in the front yard and one in the back. The inspector says that it was originally plumbed this way because the sinks and toilet in the front of the house (3BDR, 2700 sq ft) go to the front tank and the toilet and kitchen in the back of the house go to the rear tank. 

I don't remember the capacity of the tanks either but it was 400 gallons that was mentioned. Either two compartments of 400 gallons (800 total) for each tank or maybe 800 gallons total but that couldn't be right. The inspector says that the capacity is fine for this size home.

Those tanks definitely don't have an access plate. They had to remove the whole top cover of the tank to get inside. The inspector says that I might want to rent one of those core drills at some point but that is not anything I've done before.

Both tanks have been found though because the county had diagrams when they were installed so the inspector knew exactly where they were. As large as the tree is, it had to have been planted when the house was pretty new because the home is 20 years old and the tree is at least 25 ft tall. Why would the original owner plant a tree in such a place? It doesn't make sense!

Here's maybe a dumb question but I'll go ahead and ask....it seems that I'll have to be careful about getting rid of the stump - I probably can't use a stump grinder because the tank is right beneath it. Could I have the tree cut down and leave about 3' of stump above ground and then dig up the roots and then cut those out with a reciprocating saw? I am thinking to leave a bit of stump above ground so that I have some leverage and can rock it around a bit?

Jeff


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## sheeter (Jan 14, 2007)

Jeff,

I would recommend that you cut the tree down to about 6" above the ground. You can purchase a chemical at a hardware store or garden center that will rot the stump out. It will take a few years for it to completely eliminate the stump. I have done this in the past when I had a tree in a sensitive area. I also drilled holes down into the stump, then poured in the stump rot chemical, to speed the process up. When I was faced with this problem, I had a nice burmuda lawn and irrigation system and didn't want equipment driving into my yard.


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## Jemo (Dec 24, 2006)

Thanks sheeter, I'll see if i can find this stuff at Home Depot


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## ninja000 (Mar 16, 2021)

Jemo said:


> I wasn't sure which forum to post this question....
> 
> We just bought a house that has two septic tanks. Thanks to this forum, I had it inspected and the guy said everything was fine except it was long overdue for a cleaning. The only thing he was puzzled by was that the tanks didn't have an access plug. He had to pry the whole lid up and over in order to empty it. (I think he said it was 3-4" thick concrete)
> 
> ...


Hi, did you end up having septic tank damage from the magnolia tree. I am buying a house with a mature magnolia very close to the concrete tank and distribution box. I am very concerned about it. The tank is original at 33 years old. I am certain the tree roots can easily reach well in the leach field too. Thoughts? Thanks, Jeff


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## GrayHair (Apr 9, 2015)

This thread is 13 years old.


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