We carry out two types of soil investigations for our clients to discharge planning conditions and to design drainage solutions. These are Percolation tests and Infiltration tests.

Percolation Test

This test is the test to comply with BS6297 and Part H of the Building regulations. Percolation tests are undertaken to support the design of foul water drainage fields used with a septic tank or sewage treatment plant (STP).

Percolation Tests are undertaken for septic tank installations and STP. The tests are undertaken in 300mm square hand dug trial pits. These are then used to take the necessary readings to calculate the Percolation Rate (sec/mm).

Infiltration Test

Infiltration tests are different to percolation tests and are required to support the design of storm water soakaways, used to disperse water from roofs, roads, and driveways. We undertake these tests in accordance with BRE365.

Our on-site excavator digging the trial pits for our on-site tests. Large quantities of water are needed for undertaking the site tests. It is often easier for some clients to provide the excavator and on-site water.

A trial pit is excavated with an excavator to represent the soakaway to enable the test to be carried out, then we take the necessary readings to calculate the Soil Infiltration Rate (m/sec) enabling soakaway design to be undertaken.

Tests need to be undertaken in strict accordance with BRE365 and BS6297 including correct depth and dimensions.