If it is put below ground the weight of the earth around the tank will cause the walls to collapse.
Above ground water tank installation.
Concrete and compacted material.
Flexible hose from pumps to allow movement if installed installation considerations.
It is also recommended to use a heavy duty grade of tank hdt for its extra wall thickness.
1 prepare the tank base there are 2 types of bases you can prepare for a water storage tank.
To maximise the life of your tank you can prepare your site as follows.
Tanks specifically designed for above ground use cannot be put underground.
Consult factory for above ground installs.
It is important that tanks be buried into ground up to only three quarters 3 4 or 75 of its wall height.
A 3 step process on how to install a water storage tank.
Install 90 degree elbows at outlet bulkhead fittings to allow pipes to deflect with tank expansion water tanks.
See water waste management tanks under the products tab at the top of the page.
Tanks can be either placed on a 75 100mm bed of crusher dust not sand levelled boxed and compacted or 100mm thick concrete pad.
Installation of a new 5 000 gallon poly water tank at the ranch.
We do make septic and cistern tanks that are designed to be buried.
Tank must then be filled with water above ground height then back filled with bedding sand or metal dust.
Above ground water tanks.
All water tanks must be vented with minimum 2 diameter pipe.
Site preparation and maintenance.
Tanks are for burial.
Cement stabilise this fill medium.
Here is a quick process that i found very easy to understand.