In need of a new sewage system but can't decide whether you need a Septic Tank or a Sewage Treatment Plant?
Well, here are some basics on how they work and how they differ:
A septic tank is a very simple device, essentially it’s a trap for solid waste with a run-off for waste water and because it’s cost effective it remains a very popular solution.
What will you need to install a septic tank?
First of all you will need to find out whether you are allowed to discharge from a septic tank to the ground (via a soak-away).
For this you will need to perform some percolation tests in the ground to establish if your ground conditions will cope with the waste water discharged from the septic tank. Because this waste water is untreated, the Environment Agency is quite strict about where you discharge and here are the requirements:
Your septic tank soak-away must be at least:
- 10m from a watercourse or ditch
- 50m from any water abstraction points
- 15m from any building
- sufficiently distant from any other soak-away, including roof water
- 2 metres from a boundary
The soak-away or drainage field area should be down slope of any groundwater sources and no water supply pipes or underground services should be within the soak-away area. No access roads, driveways or paved areas should be within the soak-away area.
The water table or bedrock must not, at any time, be within 1 metre of the bottom of the soak-away pipe itself. This usually means it has to be a minimum of 2 metres below ground, at all times. No rainwater must be allowed to enter the septic tank system.
Sewage Treatment Plant
A sewage treatment plant works in a similar way to a septic tank by acting as a trap for the solid waste and discharging the waste water but with a big difference.
Sewage Treatment Plant units are designed to treat the waste water before it is discharged, thus a sewage treatment plant is permitted to discharge to a watercourse such as a river, stream or pond and in many instances can be discharged into a storm water soak-away.
There are still regulations that a sewage treatment plant must meet in order to be legal.
Requirements for a sewage treatment plant:
- Must conform to EN12566-3
- Discharge is subject to approval from the Environment Agency
- Must be at least 7 meters from a property
- The discharge point shall be more than 10m from any habitable property
- If the discharge is to a soak away a sampling chamber must be provided before the soak away.
For more information and help please call our support team on 01296 326111.