# Mystery Underground Water Tank



## evansbrothers (Mar 3, 2007)

Hi,
I'm wondering if anyone can help with iding this tank. I'm doing a project on a rental property that has had foundation leaks in the basement for years. We are correcting the poor grading, leaking gutters, the broken underground pipes, replacing all the black corrugated flexible crap with pvc ,installing new galavanized window wells,etc. That should rectify most of the problems. 
What I cannot figure out is what this underground tank off the side of the house is for. The owner says it was there when he bought the place 25 years ago & doesn't know what is for either. The only problem is: Its leaking from inside & the water has eroded the masonry joints on the basement brick stairwell wall & even managed to get into the basement foundation block walls which now have begun shifting.
It looks to be a galvanized tank, app 8' x 5' & 8' deep. There is a small 2" open pipe coming up through the bottom(see pic) which I believe is where the water comes in. The corner of the tank bottom nearest the house looks rusted & pitted which is where the water leaks out toward the house.
The house has a backyard pool but the pool company said it has no connection with the pool. Is it possibly some kind of a pressure relief tank for an underground spring or stream? The cast iron manhole cover say "Sweetwater, Tenn" & the cover size. Thats the only info anywhere on it. 
The water on the basement stairwell wall (both the OUTER wall & inner wall) are constantly wet & I was checking when we had a 3 week drought here last month, not a drop of rain and the walls were wet. I've checked all the plumbing lines, even shut the water main off since the house is vacant while we're renovate the interior. Still wet.
I've attached pics. Any thoughts? Thanks!
Steve
(I think this link will work but if not there is also an album with photos in my profile.)
http://s255.photobucket.com/albums/hh134/evansbrothers/water tank/


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## dayexco (Mar 4, 2006)

is it a cistern? any signs of piping from downspouts to it? have water tested to make sure it wasn't a fuel tank, if just water, pump it out, and fill full of k-krete


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## Sweebs (Jan 31, 2011)

cistern


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## tgeb (Feb 9, 2006)

Tracing the pipe that you say is where the water comes in, would be key to how to abandon this. You don't want to make matters worse.

If you can find the source of that pipe, and the water, and can find another remedy for the reason why it is there in the first place. Then you can configure a plan for abandonment.

Just filling it with out knowing its original purpose would be a mistake.


I'm local to you, call me if you need further advice, I'll be glad to help you figure this out.


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## evansbrothers (Mar 3, 2007)

*cistern*

Isn't a cistern basically a tank for storing rainwater? The only way water gets in is through that 2" pipe on the bottom. There is no piping into it from any of the downspouts or yard drains. 
There is quite a bit of silt & sand on the tank bottom which must be coming in also along with the water. The water itself that is in the tank is perfectly clear & there is no algae or anything that I can see on the walls. 
This house is in Washington DC, not exactly an arid location, so storage of water is would not have been a concern for installing this thing. The house was built in 1952 in a section of DC that does have quite a few creeks & streams. However, It is located well above any nearby waterways.


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## woodchuck2 (Feb 27, 2008)

Water storage tank? Never heard of one under ground but i have one in the small basement under my home. Mine is at least 1k gallons and was put in before the house was built. The home was built in 1902 and the small town i live in had a town water system that was fed by a large spring on top of the mountain. Later a well was dug and pipe ran from that to the tank. The tank i have is black steel and is riveted together.


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## dayexco (Mar 4, 2006)

think about this...only 3 reasons to have a buried tank on property...does it smell like diesel fuel? does it smell like sh!t? or is it an orderless fluid? if it smells like sh!t, it's no doubt something to do with the septic system....if it smells like diesel fuel, it was no doubt a buried fuel tank for the heating system....if it has no odor...still be my guess it's some form of a cistern or other water storage device.


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## mudpad (Dec 26, 2008)

Cistern. Anything else would be made of a different material. But get it checked out and make sure. You don't want the EPA all over your keester.


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## evansbrothers (Mar 3, 2007)

*tank*

Thanks for the responses. I pumped out what water was in the tank and raked up the bottom today.There is a 3" layer of black sludge (btw there are no odors at all of crap/fuel/rot/etc) under the top silt layer. From what I can tell, this mud is seaping in through the seams that have rusted away flowing down the sides. 
While I was there the next door neighbor came over and I asked if she knew what it was. She had never noticed it before BUT said there is indeed an underground stream in the area and that all the houses along this section have had damp basements & drainage issues. The houses were apparantly built on an incredible amount of fill dirt (clay mostly) in order to level out the valley somewhat. From looking at an old map of the area, it looks like the stream was filled in along with everything else. I'm going to run a snake down the pipe to see how far it goes tomorrow.
She also said there was never a septic system because her house was the oldest one, built in the 40's, & the city installed sewer lines in the area at that time.


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## cexcavation (Apr 17, 2008)

My guess is a de-watering tank AKA Water Table Sump. Due to the hole in the bottom and the aforementioned underground creek, they may have been trying to penetrate the water table and place a pump in this well. Sort of an isolated french drain. Not saying it would work all that great, but that may have been the idea behind it. Otherwise it is just a cistern like everyone else stated.


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## tgeb (Feb 9, 2006)

Sounds like you're getting it figured out, bit by bit.

I bid an addition in an area of DC that, although the property was quite a ways from the stream valley, I was confidant there was a spring on the property and had a plan to deal with it.

I did not get that project and when the other guy did the dig.....water flowed in from the banks of the foundation hole and brought the neighbors yard with it. :blink:

It's been kind of a dry summer so far, you might not base your decision on how to deal with this on the fact there is no water "now" coming into the structure.

Tracing the pipe back is key to figuring out the purpose of this......thing.

You are on the right track, let us know what you find.


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## evansbrothers (Mar 3, 2007)

*tank*

I thought exactly that as well when I first saw it Cex, that it was installed as sort of a massive french drain. Tgeb, it still is filling with water, as I say, it makes no diff if it rains or not, it continues to fill up a few feet. I'll see tomorrow if the water is back to the pre-pumpout level. Where was the job you bid? This is in Rock Creek off Oregon Ave in NW.


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## Cuda (Mar 16, 2009)

I would use a sewer camera in the pipe (not to see anything) but to trace where it goes. Maybe restore the ability to drain if it is a water cistern.


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## tgeb (Feb 9, 2006)

evansbrothers said:


> Where was the job you bid? This is in Rock Creek off Oregon Ave in NW.


Yep, same area. 

This site had water running out of the ground all the time.I had a plan to lower the water table below the foundation prior to excavating the basement addition.......the other guy had no plan or clue as to how to handle the wet conditions, I heard it turned into a small disaster.


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## evansbrothers (Mar 3, 2007)

*tank*

Well, as of today the tank still has water seeping into it through the sides. Not much since yesterday, but its there. The owner, who is cheap as rat s*** wants me to install an elevated sump pump on the bottom & run the line out to the middle of the front yard, about 70' away. I had suggested getting a sewer cam to be certain whats in there, but the guy is cheap. 
The whole yard is a sponge, the concrete pool deck is heaved up & has major cracks everywhere & the side of the driveway has about 5 inches of standing water on it constantly. "Its a rental" says he. Okeedoke.


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## griz (Nov 26, 2009)

I know the Golden Rule is that one has to work to make money....:thumbsup:

But, when you have a cheap/dumb A$$ who has a problem & doesn't want to resolve it IMO it is best to walk, no run away. The cheap/temporary fix will not work or fail & the last one to touch it will be on the hook. And the HO/Slum Lord will make sure every one knows how "you" screwed him over.


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## AustinDB (Sep 11, 2006)

you mentioned sludge in the bottom of the tank. any chance this is a grey water tank-accepting water from the tub/sinks? In Kentucky it was more common to see cisterns as a means of holding water for the house pump.


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