Filling a cistern

[Number15]

Found what I think is a cistern while mowing the other day. Luckily I saw it as I think it could have been disastrous if a tractor wheel found it first.

it's around 5ish feet in diameter and lined with some kind of mortar or clay and concrete. PO seems to have tried to fill it with tree parts but I am thinking that is not the best solution.

Right now it looks like an awesome burn pit. I will however need to fill this, it is to big of a liability. Should I remove/burn the wood that is in there? I am thinking as it rots it will settle. When filling should I use all dirt? I was thinking perhaps fill it with some kind of rock and topping it with dirt. Or should I go full bore and call the concrete truck I have no idea how deep it is at this point.

 

[Egon]

Fill with dirt and leave mounded for settlement.

 

[DJ54]

Got a gravel pit close..?? Concrete, or fill sand would probably be better to work it's way down around those chunks of wood. Make a slight mound as mentioned, and every time it rains, it will wash the sand down around those pieces of wood. You could pull out what you can to get a good start. Burning may be an option for the very top, but doubt it wil burn very deep, because of lack of oxygen, unless you provide an air source. I'd imagine the wood that's down a few feet is water logged anyway.

 

[4570Man]

I’d pull the wood out or burn in place if it will burn and then fill with dirt.

 

[texas42]

Pull all that wood out down to at least 6’. Look for ladder type inset steps in the sides. Climb down with cordless grinder, when you find the door near the bottom, cut the lock and possibly the hinges if exposed on the outside. Once inside, carefully film and document all WW2 weapons and post on TBN so we can help identify. DO NOT touch hand grenades if found! Look for tunnels leading back to house. Inspect with caution.

I would not go down in it. Too much chance of some type of gas that could overwhelm you. Very dangerous. Do all your work from top where you are in fresh air

 

[Number15]

Don't worry, I have no intention of going into it

 

[grsthegreat]

Ya, you’d probably fall into a farmers home made septic tank

 

[Wagtail]

I forgot to suggest forced air ventilation. Good call.

When working around old cisterns or wells, I'd first check if any neighbours own a collie dog.

Especially if the OP's name is "Timmy".

 

[grsthegreat]

My dad was always rebuilding the tv, but we went to thrifty where they had the tester and spare tubes. Crappy TVs, but could be repaired for a few bucks

 

[jigs_n_fixtures]

pull Most of the wood out. I doubt it will burn in place, it would be hard for combustion air to get in.
knock a couple of feet off the top so it is below ground level. Then back fill with reject concrete sand. It tends to be self consolidating. The other option, but more expensive, would be a Controlled Low Strength Material. Essentially a 3/8-inch minus Portland Cement, with only 1/2 to 3/4 sacks per yard, a high water to cement ratio, and plasticizer added. It should have a 10 or 11-inch slump so it is self leveling.