Sizing a Soakaway - Why it's better to be safe than soggy!

A well-designed soakaway or drainage field is a network of perforated pipes and gravel, installed in a grid system, intended to ensure foul or storm water drains away efficiently, or in the case of foul water it treats the water as it drains to ensure it is environmentally safe to enter the ground. Here at CM Environmental, we cannot stress enough how important it is to ensure your soakaway is designed safely; a poorly designed system, such as the one shown above, can lead to unpleasant smells, flooding of foul waste, and your foul water system backing up.

The Environment Agency and Building Regulations both insist that a drainage field needs to be designed to meet the requirements of the location. This is because ground conditions can vary hugely from location to location, and water will drain away faster in some ground than others. Clay for example takes a great deal of time to percolate, whereas gravel or sand has a high absorption rate. A percolation test assesses the condition of the ground by timing how long water takes to drain away (at the depth you intend to install the soakaway.) CM Environmental can undertake a percolation test for you, or offer the instructions on how to do so for yourself.

Once we know the results of your percolation test, and the expected flow (how much water it will need to drain) we can then help you size the required soakaway needed for your site. Previously, it has always been the home or land owners' responsibility to ensure a soakaway was sized accurately, but under the new British Waters Guidelines, more responsibility is being put on drainage consultants and installers to ensure the soakaways they design or install are fit for purpose. CM Environmental has no problem taking complete responsibility for a drainage field design as long as we have undertaken the percolation test, and evidence is provided of install that our design has been adhered to.

If your soakaway has previously worked with no issues and now you have the earlier mentioned problems, it is worth knowing that a soakaway does have a shelf life; a system that has been installed for a number of years may silt up and fail, or be destroyed by tree roots, meaning a whole new system is required. If this is the case, you may find the works are insurable under your home and contents insurance. CM Environmental works with a company who may well be able to help with this. The staff at CM Environmental can talk you through the installation of a drainage field, or even install this for you if required.

Please contact us at the office on 0115 684 8356 if you would like any guidance with percolation tests or soakaway design. Or any other drainage concerns. It is definitely better to be safe than soggy!