construction/contactor help needed

[hotreds]

I have a 10,000 gallon cistern that has one wall as part of my utility room. That wall has developed a crack, and I have a leak. I have tried to patch with Quickrete water stop cement, Drylock sealer, and the water stop spray you see on TV. I now have a huge pimple on the wall, but still have a trickle of water. Over night, that trickle leaves a nice puddle.

Any suggestions on what to do to finally seal this(these) leaks? Someone suggested roofing tar.

HELP!

[jumper]

I don't think you will ever have any luck patching the wall from the 'dry' side. Can you get into the cistern? Can you stop it from filling in order to inspect the crack from the 'wet' side.

[hotreds]

Supposedly it was sealed from the inside last time it was very low. It has about 7,000 gallons in it right now. I don't want to pump it out at this time, what with rain being so rare these days, and buying water getting expensive. What can I do for now until later in the year when the level lowers and I can get somebody in there? Just suck up the small puddle every morning?

This is my only water source- I do not have city water.

[jumper]

I'd say you have to think of the concrete wall in your utility room as the inside of the hull of a ship. The water in the cistern is causing constant pressure and that will aggravate even the best patching methods. The 'pimple' you speak off is the water pushing through the crack and forcing the patch material away from the wall. Eventually the bond will break and it will leak more. Most interior patch methods are designed for cracked concrete walls that seep rainwater from around the elevation grades and that is rarely under any pressure. The majority of leaking walls are repaired from the outside these days and it always involved excavating the backfill down to the footing and waterproofing the wall on the exterior side.
As well, were I you, I'd check with my local building codes to see what sort of chemical agent you are allowed to use when in contact with your drinking water.
In the meantime I'm afraid you are stuck with the wet/dry vac and hope the humidity doesn't get too high in your utility room.

[mongoose]

You have no choice but to deal with it until it can be drained.

Polyurethane injection would stop the leak but since you use it for your domestic water supply is out of the question because it is toxic and injected epoxy will not bond properly in wet conditions and is also toxic until fully cured.

[Slash McCoy]

Regrettably I believe they are right. It must eventually be patched from inside the cistern. Hopefully it will not get much worse before you are able to do so. Hate to be a gloomy gus about this but it is what it is. As far as patching it from the outside, the pressure from the inside is your mortal enemy. You want the pressure to help you, not fight against you, so patching from the inside is the only practical way.

If the leak is small, maybe you could temporarily patch it from the inside with beeswax or some other non toxic substance, without draining the tank. Of course you would have to be able to find the leak from the inside for this to work. Just guessing from the outside location might or might not be good enough.

[hotreds]

I am looking into a number of options including a liner for the cistern. There are also several products by Ames http://www.amespaint.com/mm5/merchan...Store_Code=AWM that I will look into for the time being. Indeed, looks like a final solution would involve the inside of the cistern.