It was a 10 foot tank,
I would put the stairs entirely out side of the tank, if doing again, currently it is about 50% 50% as I used the stem wall as a step,
I am not sure if I could fine the correct tank, 10 to 12 in diameter if I would not just roll the whole tank in the hole on a level bed of gravel, (water poof ed, tared first) and then put a floor in it and weld on some brackets for shelving, Would have been less work, may be even fill with gravel and a cement floor.
we like the cellar, and have no water problems, but we are 280 feet deep to water,
we did need to add some aeration to the system as condensation was some what a problem, added a intake vent of about 6" and a exit, with a wind powered ventilator on it,
I did put a sump pit in the floor never have needed it (yet), fingers crossed,
I do like the square walls on the base of it tho, but
but using the tank some thing like this would not be to bad.
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