Percolation tests for septic tank soakaways are performed to determine whether a new septic tank and soakaway system can be installed or to determine where a replacement of an existing system can be replaced and renewed on the same property.
You must first do the Ground water source protection zone check ,then a trial site assesment hole and then you can perform the percolation tests.
The percolation test for septic tank soakaways , should begin with invert level of the outlet pipe on your new or existing septic tank, example 500mm. Dig the first test hole to 900mm deep x 300mm x 300mm as this will be the level of the ground that will take the actual liquid run off from the tank.
On day one fill to a depth of 300mm with water and leave for 24hrs to soakaway.
On day two fill to a depth of 300mm and set your stop watch and time how long it takes the water to soakaway.
The size of tank for the size of property and the calculation from the percolation test will determine the size of the soakaway system required in mtr sqared. you can then divide this by 0.3 for a 300mm wide trench or 0.6 for 600mm wide etc etc and then the lenght perforated pipe soakaway system you require in mtrs . please see pic example of the soakaway layout. eg only shown.
you should never use soakaway crates or soakaway tunnels on a septic tank soakaway.
our polybed and polyagg combinations have all the relative building pass paperwork for both septic tank and sewage treatment plant soakaway systems.
On our website it clearly states which products are used for foul drainage systems and which are for rainwater use only , please dont hesitate to call asap septic tanks to avoid confusion.