A percolation test is necessary to establish the porosity of your soil so the correct septic system can be installed. You will need documentation signed by the builder and the sign off must be in compliance with the planning conditions established by your Local Authority or County Council. If faults arise in the waste treatment system later, you may need this documentation.

The percolation test is most commonly carried out by a qualified site assessor, however some local authorities may request you use someone from their list of pre-approved assessors. It’s a good idea to consult with your local authority or council before appointing your site assessor.

The percolation test will help determine the best system most compatible with your soil, usually some form of septic tank or on-site treatment system with a percolation or leaching area.