BS6297 Percolation Testing
What is the Difference between Soakaway (BRE365) & Percolation (BS6297) Testing?
What distinguishes a soakaway test (BRE365) from a percolation test (BS6297) is their respective purposes.
A BRE365 soakaway test is necessary to assess the suitability of a new or substitute soakaway for the discharge of surface water runoff, while a BS6297 percolation test is necessary if a septic tank or sewage treatment plant is being proposed for the treatment of foul water.
What is a BS6297 Percolation Test?
A BS6297 Percolation Test is a shallow in-situ soil test carried out to determine a site’s suitability for shallow drainage fields serving septic tanks or package treatment plants.
The procedure measures how long it takes a measured volume of water to drain away from a trial pit; the result determines the suitability (and permeability) of the soil, and ensures that the ground has sufficient drainage capacity to handle the amount of water that will come from the drainage field you intend to install.
If drainage is too slow a system will not function and cause flooding, but If drainage is too fast there is a risk that effluent may adversely affect groundwater.
By performing a Percolation Test, the correct drainage systems can be installed on the property, ensuring efficient wastewater disposal.
The British Standard Code of Practice for the Design & Installation of Drainage Fields for Use in Wastewater Treatment, BS 6297:2007+A1:2008, sets out in detail how a percolation test should be carried out.
How is BS6297 Percolation Testing undertaken
Excavate trial holes 300mm square to a depth 300mm below the proposed invert level (bottom of pipe) of the infiltration pipe along the proposed line of the subsurface irrigation system.
Each trial hole is filled with water to a depth to at least 300mm and the time for the water to seep away from 75% full (225mm depth) to 25% full (75mm depth) will be recorded. The Percolation testing is repeated up to 3 times in each hole.
JAYSTONES will carefully excavate the trial pits and undertake Percolation Testing in accordance with BS6297.
It is normally recommended that the worst case results is used for design.
We can supply all materials and labour including water supply.
Alternatively if a sufficient water source is available on site we can simply undertake the required testing and provide the results.
Jaystones only use Licensed Water Authority Standpipe to obtain clean water.
