Sewage treatment plants come in many different sizes. While most are for domestic properties and are fairly small-scale, some need to be ‘sized up’ for a variety of reasons. Here Gilson Environmental Services, who are leading sewage treatment plant installers in Suffolk and across East Anglia, examine why homes and businesses may need this type of system.


You Can’t Connect to Mains Drainage

The reason why people need sewage treatment plants in the first place is because they can’t be connected to the mains sewage system. This applies to about 5% of all properties in the UK.

This may be for geographical reasons where it isn’t economically feasible for the water authorities to connect you up, such as in very rural areas where no existing pipework exists. There may also be infrastructure reasons in more built-up areas, such as the logical place for pipework associated with mains drainage may be blocked by other underground facilities, such as railway lines.

So you may need a treatment plant, but do you need a larger one?


It Has to Cope with A Larger Number of People

Commercial properties such as offices and factories often have large numbers of people working there. This will be reflected in a larger amount of sewage, particularly if there is a staff canteen.

Working patterns may also affect the amount of sewage the plant has to deal with. If everyone starts and clocks off at the same time, this could put a strain on the treatment plant, particularly if it is under-sized.

Some residential properties also need bigger sewage treatment plants because there is a large number of people living there. For example, some shared properties such as blocks of flats and houses have been divided into multiple residences.


It’s the Law

This issue of size is also reflected in the Environment Agency’s own recommendations on dealing with non-mains drainage for larger sites. While cesspits and septic tanks may be a possible solution for some smaller sites, the only alternative for systems that have to deal with the sewage of more than 15 people are sewage treatment plants.


The Issue of Sizing

You can’t simply assume that, if you need a sewage treatment system that will be used by 50 people, it will need to have a capacity 10 times larger than one which is only used by five people. This is because there are a lot of variables you need to take into consideration.

An office with 30 workers is thought to be the equivalent to around 10 domestic residents.  These figures take into account factors such as the time they actually spend in the office (lunch hours/visits to other businesses), staff holidays, etcetera.

This process is known as sizing. In general terms, it’s always better to round up in terms of system capacity rather than round down, although it is worth bearing in mind that some sewage treatment systems actually suffer if they are under-used.


Gilson Environmental Services – Sewage Treatment Plant Installers in Suffolk

But don’t worry if you don’t understand all the complexities involved, as Gilson Environmental Services will be able to work out what size you will need. And this isn’t just larger sewage treatment systems but smaller ones as well. We have many years of experience in installing, commissioning and decommissioning, and maintaining all types of systems, including cesspits and septic tanks from our Ipswich base.

Because we aren’t tied to any particular brand we can give independent and impartial advice, meaning we will only recommend the type (and size) of system that meets your exact needs.

If you would like to know more about our services, you can call us directly on 01473 741530.