London’s Luton Airport has installed the Uk’s first stormwater treatment plant in an aim to change the way surface water run-off is treated. The system integrates attenuation tanks and sustainable drainage (SuDs) with the SDS Aqua Swirl - equipment that uses vortex separation to extract substances such as oil and de-icing chemicals from the water to mitigate pollution. The leftover water will then be sent to one of three receptors: the River Lea, an underlying Chalk Aquifer or Luton Hoo Lake.

£110 Million Project

Planning for the project began with a long-term surface water drainage strategy, commissioned by London Luton Airport Operations Limited (LLAOL), for the airport during September, 2014.

One part of the £110 Million project aiming to redevelop the airport was the expansion and resurfacing of car parks which would create more impermeable surfaces and increase the risk of flooding. A new sustainable drainage solution was therefore required to safeguard the quality of the water running into the environment.

The System

During April 2016 a new SuDs system was developed and installed to control surface water run-off from Luton Airport’s car parks. Five SDS GEOlight attenuation tanks were added with a total capacity of up to 4,277m3. The water will be cleansed by two SDS Aqua-Swirl hydrodynamic vortex separators designed to eliminate up to ninety five percent of total pollutants in the water run-off.

The installed SuDS system has cut down the volume of water and frequency of the flooding that arose in the underpass of the neighbouring Airport. Although the flooding hazard for both carriageways remains in the ‘significant’ category for a 1 in 100-year storm event, the severity of flooding throughout the access route in a thirty year event has reduced to ‘moderate’ for one of the carriageways, while for a 1 in 10-year event, the second carriageway is considered completely clear, while the installation of a pump which is able to transfer flows to the SDS GEOlight tanks ensuring that emergency access is clear at all times.

Water tanks within the underground storage facility are installed to cater for excess airside surface water run-off - which will be highly contaminated with substances such as deicing chemicals - and will be directed towards the Thames Water foul system for treatment.

What Next?

While landside and airside run-off are typically considered as two entirely separate wastewater streams, LLAOL are developing plans to manage all sources of surface water collectively, especially the control of their distribution, in the most environmentally conscious way.

Belmar Technologies design, build, install, commission and service complete industrial wastewater treatment systems for a wide range of sectors. For more information or to discuss our services further, please feel free to get in touch either by email to or by calling +44 (0) 1327 586 008.


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