Above Ground Pool Possibly Over an Old Seepage Pit

by Jack
(Bergen County, NJ)

Mr. Pool Pro, I am a homeowner with a backyard that can easily fit a small 12'round Pool. We recently discovered the backyard might possibly have an old Seepage pit from the 1940's, we discovered this from an old survey we obtained from our town dated 1967.

There was an old septic system underground buried in the front lawn, with a seepage pit and well in our backyard which were all connected. Then in 1970, the town installed a sewer system on the property.

Here is my question, this 'seepage pit', which is 10' x 10' x 10' underground (According to the diagram), would it affect us installing a 12' Round pool with 3,000 gallons of water?

What are the chances this pool might collapse, although there might possibly be (we are not sure) a seepage pit almost 6 feet below ground?

We are also unaware if this seepage pit was removed or even filled up if left underground. I did discover a very large rock near the back right hand side of the yard, possibly used to cover a very large hole, however that has nothing to do with the same location of the pit, which is situated in the middle of the yard.

Lastly, we were told by two of our neighbors that the previous owner discovered an old 'well' dropping 7 feet down, I say 'well' because it had the characteristics of a well with a round brick wall with no top, the prior owner had an excavation company fill it with rock and sand for no more hole.

With all this in mind, do you think its safe to install a 12' Round pool with 3,000 gallons of water on our back lawn? We are so desperate to have a pool with this hot weather and all, but do not want to make any mistakes or cause any bodily injury. The location of the property is in Bergen County, New Jersey. Any advise would be appreciated.

Thank you, Sweating in NJ

Hi Jack

I would have no problem setting a 12' pool up in just about any yard. There is just not that much water weight to worry about.

If you are concerned I would level the area and then water and pack, water and pack, for a period of a couple of weeks. If the ground remains firm and solid it should be fine for a pool.