Cistern Leaking

[mindless1]

I need to fix a leaking cistern. This was the sole source of water for a building that now has city water, and an interior wall of the cistern has cracked from the top down and is leaking into the basement.

This is not a high value building so expensive foundation work is best avoided. We do not need to and don't use the cistern any longer.

Can I just pump the water out and leave it empty? There is no reasonable chance of animals or children falling inside. Must it be pumped out, at least below the level of the crack to patch the crack? One concern is that while we don't have any feed to it, no gutters or anything, that it might still be picking up water over time.

I tried using hydraulic cement to patch the crack but it wouldn't hold with water seeping through. It is seeping at a low rate, a few drops a second.

Is there something else best to use to patch it, or can I just empty it as much as possible, and then do I need to fill it with dirt?

Thanks!

 

[Blain]

Why not pump it out and cap it?

 

[mindless1]

Yes pumping seems inevitable but it would be nice to patch it then wait to pump until it's above 20F outside and not snowing. Then I wouldn't be out in that weather and the water would have a better chance to dissipate. I guess I could pump it into the sewer or are there likely to be laws against that?

As far as capping this is a fairly old and poorly constructed building which may have areas on the cistern that are leaking in water besides where it would be capped. The fill hole for it is already under a porch overhang that is slightly above ground level with a downhill grade nearby so if it is refilling from ground water it may be doing so from somewhere else.

 

[Blain]

I guess I don't understand your need to patch it after pumping it out.
As long as no water is being diverted into the cistern, it would only collect a minor amount of natural ground water.
The same ground water that would be in the area anyway. If the ground water is leaking into your basement, the cistern wouldn't be much of an added issue.

 

[mindless1]

I want to patch it before pumping it out if possible, to buy some time until it's warmer outside, and for the time being to keep water from soaking some equipment in that room which has some value but isn't easily moved.

I (or someone) has to pump it a fair distance (minimum 160') if it's going in the ground (making an ice pond for the time being) instead of a sewer and I had a thought that in these temperatures the 3/4" hose I'd otherwise use at a different time of year might freeze up, clog

I suppose I could rent a higher flow pump with larger diameter hose to increase odds it won't freeze up... not sure what the temp. is in the cistern right now, it is in-ground except the porch over it, but the building heat was turned down low for the winter due to no occupancy for more than short periods, basically kept only high enough to keep pipes from freezing while still having running water available from the city.

Anyway there is a guy on-site for another reason today and he'll let me know if the leak is being kept in check with the fans I have drying the area out after shop vac'ing up standing water.

 

[waffleironhead]

Iirc, decommissioning a cistern usually involves busting holes thru the bottom to ensure drainage, then filling with soil/gravel/rock. Then capping the inlets with concrete. I'd check with your municipality for their specific requirements.
For the time being you could pump it out, but until you figure out how it is filling, it is just going to refill once spring thaw comes.

 

[mindless1]

Heard back from a guy at the site and the fans are keeping it in check, though I would assume the longer it leaks, the higher the humidity rises and less effective the fans will be.

At least it's looking like I can wait to get a contractor out Monday or later, originally to estimate repairing something else but now having him look at the leak and cistern while he's there.