Sewage treatment plants are becoming increasingly common as a method of off-mains drainage. Alternatives such as septic tanks are now subject to much more stringent regulations thanks to the General Binding Rules.

Gilson Environmental Services provide expert sewage treatment plant servicing from our base in Ipswich. Here we look at some of the key reasons why regular maintenance and servicing are essential for this type of off-mains drainage.


A Build-Up of Sludge

Sewage treatment plants operate by separating out solid and liquid waste in a primary tank before the effluent flows into a secondary tank, where it is aired and purified before being released. However, over time a build-up of scum – rather like a crust – can occur on top of the effluent in the primary tank, whilst a sludge settles at the bottom.

Eventually, the sludge will build up and effectively reduce the capacity of the tank due to less space between the sludge and the scum. If there’s no room for the effluent to enter the tank, this can lead to blockages further back in the system which can result in leaks and burst pipes connected to the tank (and potential damage to the environment.)

One tell-tale sign of this is that your drains are taking longer than usual to clear; and if you can smell any foul odours in the vicinity of your treatment system then it may be full or very close to capacity.

So regular desludging will ensure that the system continues to operate efficiently. This is particularly important for larger installations which come in for a lot of use. Some treatment systems require a certain amount of sludge to encourage the ‘good’ bacteria to grow and flourish. It’s essential that this work is carried out by qualified professionals.


The Electronic Parts

Sewage treatment plants all have some electronic parts and their precise nature depends on the make or brand. For instance, disc systems use a motor to turn a belt-driven chain or sprocket attached to a rotating shaft which encourages bacteria growth on special discs, while air operated and pumped systems both use an electronic air pump or blower.

A service will determine whether the pump, motor or alarm is operating efficiently and whether it needs replacing (some manufacturers may recommend this after a number of years anyway, whatever condition the unit is in).

Specific problems which can be encountered include:

  • The blower operating but not pumping air – this may be because a filter is blocked, the blower itself is damaged or because of a problem with the power supply.
  • The blower operating but not delivering effluent through the system – this is usually caused by a blockage somewhere, either in the tanks or in the pipework leading to them. Failure to rectify this could lead to a costly breakage somewhere.
  • The blower stops and starts erratically – this may be due to the pump overheating, in which case it should turn itself off automatically until it has cooled down sufficiently. It could also be a sign that an air supply vent has become blocked. Another reason could be that your system has not been used for a while and has ‘run dry’; sometimes under-use can be as big a problem as over-use.


Sewage Treatment Plant Maintenance in Ipswich from Gilson Environmental Services

At Gilson Environmental Services, we can service all types of sewage treatment plants. We are fully accredited, aren’t tied to any particular manufacturer and we have an excellent knowledge of all the major brands, including their disc, air or pumped treatment systems. Generally, we would recommend servicing all systems at least once a year but some manufacturers’ service intervals may vary.

We are also one of the leading sewage treatment plant installers in Suffolk and further afield – so if you ever need a completely new system, we are the people to call. For further information about any of our services, email us at or call us on 01473 741530.