Concrete underground storage tank crack and leak prevention?

Question

I am building my own underground storage tank (UST) out of concrete and have heard that the tank can crack, creating leaks and loosing water. I would like to know if there is a way to prevent this from happening...? thanks!

Answer 1

You can use a product called THOROSEAL.  Thoroseal is a cement based, micro-porous (breathing) , seamless coating used to fill, seal, waterprooof, and protect a variety of substrates including cast-in-place and pre-cast concrete.  Their website: ThoroProducts.com

Answer 2

Use lots of rebar and wire mesh, thick walls, and fly ash to strengthen the concrete.  Order the fly ash mixed in the concrete, and a vinyl admix if they have it.  make sure the tank is poured in place so it can conform to the irregularities of the soil around it.  One thing more to do is to line it with liquid plastic or a tar sealer on the outside if not poured in place.  Would it not be easier to get a large plastic tank and put that in the ground?  Backfill with lots of sand to keep it from moving.  It may be cheaper than the concrete, and easier to replace or repair, or remove later.  I plan to put one under ground where the old cess pit used to be.  I plan on running the Ac copper pipe around it to precool it before going into the condenser.  The tank will be used to store rainwater, and some shower water after it is filtered and run through an above ground concrete tank filled with reeds.  Is yours for primary drinking water, or toilet flushing?

Answer 3

cant use concrete for anything other than  non potable water because of integrity issues

Answer 4

I know that they do make a spray that you can use,I'm not sure of the name of it ,but your local hardware store should be able to help you  find somethig that will work. I have a 1000 gal. tank & a 500 gal. tank made from concrete and never had any prblems with cracking or leaking.The main thing is to make sure you get all of the air out of the concrete foam when your pouring the concrete.You can do that by taking a hammer  and tapping the side of the foam while you are pouring the concrete.

Answer 5

the concrete should only be a containment (secondary) tank.

your primary tank should be fiberglass or plastic suitable for storing potable water.  temperature change and earth shifts will crack the concrete.