Within the scope of larger projects there is sometimes a requirement to improve the existing wastewater setup or as an addition to what is already installed instead of a new standalone unit. This often happens due to the existing site undergoing expansion or increased footfall.

The former was the case with one recent installation we undertook for an industrial commercial customer in North Yorkshire whose site had increased its footfall and thus the daily flow has increased as well meaning a new wastewater solution need to be implemented.

Due to the size of the existing set up and the required upgrades the environment agency needed to be consulted in order for the works to be ascertained.

The Klargester Bioficient 55 commercial package sewage treatment plant can be used on sites as a standalone unit or part of a modular set up, as a singular system the commercial Bioficients can serve up to a PE (population equivalent) of 300 and up to 1000 in a combined setup.

For this project we looked to install the Bioficient 55 which would act as an additional treatment process to the systems already in situ, this unit is certified to BS EN 12255 meaning the system has undergone stringent testing to be able to be treated to a minimum standard. The sizing was based on the maximum flow rate of 48.2 metres per day.

For this site in particular the requirement was for the system to be able to treat to a 20:30:15 (BOD:SS:Ammonia) standard which was easy enough based on the effluent standard based on the testing carried out on the system. The Bioficient incorporates the usual 3 stage treatment process, this is done across 6 zones; 1-2 being primary settlement, 3-5 being biological treatment and 6 being the final settlement, this is done using blower driven aeration.

Despite the large excavation there was no additional requirement for any ground stabilisation due to the primarily clay ground holding its structure well during the installation process, whilst this was great for the excavation this did mean that the rain that fell during the installation a submersible pump was required to remove any surface water.

Along with the Bioficient package sewage treatment plant a pump station was also required to lift the treatment effluent from the plant to the discharge location, a twin effluent pump station was therefore installed on the outfall on the system.