Pool-So I have a concrete, inground pool in my back yard. 3' deep shallow end, 12' deep deep end. Very old, leaks like a civ, and is very expensive to replace or fix.

Backyard-large, open; trees hang over the deep end. Try to picture in your head, I think this matters. Shallow end facing deep. The woods behind the deep-end slope down, wetlands, and slope back up. Picture something that must have been a river thousand of years ago, and is now just a small creek with cedar water running through it. I'd say the creek is 30-40' below the level of the pool in my backyard. When the pool is filled, the water level is about 6" away from the top concrete edge in the shallow end, and about 2" from the edge in the deep end...I think the deep end of the pool sank over the years.

The water doesn't drain out anymore. It naturally drained down to a level of about 4' in the deep end, and stopped. This was awhile ago and we actually have to treat it for mosquitoes now to be safe. My concern is the water table. If a hole were drilled into the very bottom, would it drain, or would water come up?

How can this be taken out/caved and filled in? Will extra weight of stone or dirt hurt the deep end more, and leave me with settlement?

Just tossing this out there, I figure there might be someone whose an engineer or who has experience with this. I'd like to see about a garage over the sight, nothing serious, just for my baby. (On that note, see Suspension rebuilds for musclecars...in the General Auto Forum...help me spend my money and build my car...need some ideas, and it's fun to think ahead)

Thanks all.

 

I have no experience with this, but would it make sense to remove the pool entirely, pump out the water, then fill it in? That's probably a pricier option. I'm not sure if you'll get very good drainage if the concrete remains there.

 

That's where the holes come into play. A few in the deep-end to drain is first, and then some more for regular drainage. My concern is with the first hole in the deep end for draining. I'm not sure where the water table is, and I don't know whether or not water will drain out through the hole, or seep in from the ground into the pool.

We don't know why it stopped at 4'...it's either a crack in the middle of the pool, or what I am afraid of, a crack in the bottom, and the 4' is leveled off with the water table. This level of water is about 8' below ground level, and we do not have a basement, presumably (I guess) due to water table concerns (the house is almost 40, the pool must be about 30-35).

*Assuming the ideal occurs, and everything drains out, we figured on drilling holes throughout the concrete for rain water drainage if we fill it in. Don't forget, the next plan of attack would be a garage over it. Nothing fancy though.

 

the best thing to do is to pull the whole pool out of the ground. if that is not feasible, punch some big holes throughout the floor and push sides in to pool and fill with sand and wash it in. if you don't push holes through it, it can pop out of the ground. i would check with a soil engineer on the feasibillity of building over it however way you go. will be expensive.

 

Like stvneil said....bore holes in the bottom and cave the sides in then fill with dirt. of course the fill has to be compacted if you're going to build on it. I have seen it done here in the south with just filling in with dirt. Pools are a pain in the rear to take care of anyway. I have an above ground pool that needs a new liner and a new liner is 350 bucks....uninstalled. Then there is chemicals....what a pain if you have no help.

 

Chemicals...none in there, last time it was filled (after being cleaned the Fall before), we didn't waste time with them. We were pretty sure that the water was going to leak quickly.

The holes aren't the question, though I agree, it will need drainage.

I guess the question may be...if the pool stopped draining at 4 feet, is it possible that it met the water table? If this is the case, what will happen by drilling more holes? Can water seep up through the holes rather than drain?

Concrete also surrounds the pool, so we'd remove that as well. I don't know about using that as backfill, but will cave the sides. Also, I assume it will require a lot of fill, and anything built on top would need a good amount of time beforehand to let the ground settle and see what it will do. Other than the foundation, the structure would be made as light as a structurally sound building will allow. Possible drainage for cleaning in there, but nothing like in ground lifts. Would a few feet of stone be more sound than dirt?

 

We fill holes where fuel tanks are removed with gravel. There is no settling time with it. If it were mine and I didn't want it, I would get an excavator to pull the concrete from the walk way into it or take a dozier and push it all in.
.02 cents worth from a southern boy.

 

Chances are the water has drained down to the water table in the ground. Best bet would be to call a well drilling outfit and ask how far down the water level is.
It could also drain down to where the leak is. Only way to find out is get in there and look for a crack at or just above the water level. In all it's going to be a costly job. There are places here where pools have been filled in and you can still see the decking and tops of the pool walls.

 

A good excavator in your area can help. For starters to fill the area correctly the pool needs to be pumped, then broken up, and then the area filled in. The water table is now apparently to high for the pool to drain on it's own. If your plans are to build in that location an approved structural fill should be used and compacted in lifts to get an adequate base for a foundation. You can't just push fill in the hole and expect it to be stable. Consulting an engineer for specs and codes in your area might not be a bad idea. If you were a little closer than 3 hrs. away I would consider giving you a price on the excavation.

 

In most states its code to have a pressure equilizing plug in the bottom of the pool. It should be under the drain grate, and is probably a 2" PVC plug. This is to relieve the ground water pressure if the pool has to be drained to work on it. Pool companies have automatic pumps to keep the water pumped out while they refinish. Also pools can be releveled by pumping concrete under them. They are tough to break up do to all the wire, rebar and gunite concrete in them.

 

Pump it out, and jackhammer a hole in the bottom. If the water runs in, there's your answer. Or, can you dig a 5 or 6 foot deep hole next to it?

Regardless, I think you need to break this thing up, get the concrete out of there and backfill with gravel if you're going to build over it.

 

If the water table rises far enough, it could fill the pool til it equalizes. If the water table rises far enough, it can pop an empty pool up out of the ground, from an inch to a fewe feet. If caving the sides is too expensive, why not just bust enough holes in the bottom as well as the sides, then back fill?

I'm not an engineer, nor do I play one on TV. But I did clean pools and repair equipment for a few years, in another lifetime.

If you're gonna build on the site, you wanna make sure it's not the whole hill that's settling.

hmmm...if the pool had a leak at the settling end, could the settling have been caused by saturated ground over a period of time?