Planning for the deluge

The Up-Flo Filters in twin wall chambers, verified to remove 80% suspended solids but with demonstrated removal rates of up to 98%.
The Up-Flo Filters in twin wall chambers, verified to remove 80% suspended solids but with demonstrated removal rates of up to 98%.

A new food production facility needed a drainage strategy suitable for an industrial site, to control surface water runoff and remove pollution. An advanced stormwater treatment solution was customised to meet site requirements.

The Eastways project in Witham, Essex, UK was an existing industrial unit that was being upgraded to include the construction of a new food production facility with internal offices, a new site entrance, and a new vehicle turning area. This construction had to include drainage to control surface water runoff and remove pollution. 

The stormwater runoff from the roofs, roads, car parks and ground area could not be infiltrated so needed to be stored within the development site for storms up to a one in 100-year event, with an additional allowance for climate change. With no nearby watercourse, the stored runoff will then flow off the site into a public sewer.

Sustainable drainage Bell Munro Consulting worked with Hydro International to find a solution. It was agreed that all site runoff was to be via conventional drainage to a public service water sewer and would include Sustainable Drainage Systems (SuDs) in underground storage with limited flows into the public sewer, and in-line control measures to remove pollution from the runoff.

Working together they developed an effective and advanced stormwater treatment solution that was customised to meet site requirements, by combining two 1.2 m Up-Flo Filters and one 1.8 m Downstream Defender. To meet the tight delivery deadline and keep the project on schedule, the Up-Flo Filters and Downstream Defender separator were supplied in twin wall plastic chambers.  The strength of the twin wall chambers meant that there was no need to back fill with concrete and it also made them lighter and easier to move around on site.

The Downstream Defenderis an advanced hydrodynamic vortex separator that captures and retains coarse and fine sediment, oils and floatables from stormwater runoff, in a small footprint. As a compact and low-maintenance stormwater treatment solution, it enables engineers to deliver effective pollutant removal at a single point in the drainage system.

The Up-Flo Filters provide an advanced stormwater treatment solution that delivers multi-stage, high performance treatment in a small footprint. Each Up-Flo Filter combines sedimentation and screening with fluidised bed filtration to deliver surface water pollution removal.

 “Working with Hydro International’s technical team, we were able to provide an advanced treatment solution that met not only the hydrocarbon pollutant removal requirements, but also removed Total Suspended Solids and metals. The flexibility of material choice for the chamber enabled us to keep to our project schedule.” - Alan Morris, Associate civil/ structural engineer at Bell Munro Consulting.