Drainage Field Installation & Repair
We are experts at installing drainage fields across the south of England. If you have a septic tank then you need a drainage field!
What is a Drainage Field?
A drainage field is similar to a soakaway but is used to disperse the effluent from a septic tank or sewage treatment plant – not rainwater runoff. It consists of a network of perforated or slotted pipework, running from the septic tank or sewage treatment plant and provides a form of treatment of the waste water, by enabling it to percolate safely through the subsoils and back in to the water table without causing pollution.
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We offer a professional drainage field installation service across the south of England without the expensive bill.
Understand the regulations
Prior to starting work on a drainage field you will need to check the requirements of Local Building Regulations.
It is illegal to discharge effluent from a septic tank to anywhere but a drainage field. You can receive a significant fine if you were to discharge in to a watercourse as this is in clear breach of environmental laws.
Drainage fields have many regulations such as being a minimum of 10m from a watercourse, 50m from a water abstraction point and 15m from a building. They also need to be sufficiently far away from any other drainage fields, mounds or soakaways. A drainage field cannot be in an Environment Agency Groundwater Source Protection Zone.
Drainage Field installation
Firstly an inspection chamber is created between the septic tank and the drainage field, this allows the drainage field to be accessed easily once it is built. Trenches are then dug out from the inspection chamber.
The trenches are part filled with gravel before the solid perforated pipes are laid forming a continuous loop. More gravel is then added on top. The gravel helps ensure aerobic contact between the liquid effluent and the subsoil.
The trenches are topped with a layer of non-woven geotextile to prevent silt entering the gravel. Finally the topsoil is replaced on top to make the area level.
Older septic tank drainage fields did not have to conform to any Building Regulations and may be a simple long trench, a herringbone drainage layout or even, a large stone filled pit. These latter types are often not fit for the purpose as they are for rainwater only.
Frequently asked questions
Want to know more about soakaways?
Would you like more information about the installation of a soakaway? Get in touch with our team of drain specialists today to find out more. We look forward to chatting with you and helping you with your soakaway requirements.
Our specialist drain repair team cover all of Surrey, Hampshire, West Sussex and Berkshire. No matter where you are we will be happy to give you any drainage advice free of charge over the phone.
If you would like to discuss our drain relining and drain repair service with one of our experienced drainage engineers: