East Midlands Diamond Drilling turns to Siltbuster to solve its dirty water problems at Birmingham New Street station

The Gateway project will transform Birmingham's New Street station into an iconic landmark with a stunning façade. As part of the project, the concourse and platforms will undergo considerable redevelopment. The concourse will be three-and-a-half times larger than at present, enclosed by a giant light-filled atrium with better access to the redeveloped platforms. More than 12,000 tonnes of concrete in total will be removed from site in order to create this atrium, with 7,5000 tonnes of concrete removed in phase 1. Work on the atrium will commence in January 2011 and the new concourse is set to open in 2012, with work due to be completed in 2015.

Siltbuster Limited, the total wastewater management specialist, has been appointed by East Midlands Diamond Drilling (EMDD), to treat silt laden wastewater generated by concrete cutting activities at the Birmingham Gateway project to upgrade New Street station. EMDD, one of the UK’s largest concrete cutting and controlled demolition specialists, is responsible for phase 1 of the demolition works. This involves the complete removal of the concrete floor slab on the mezzanine level of the NCP car park adjacent to the station.

EMDD is subcontracted by demolition contractor Coleman & Company Ltd to diamond saw cut the current car park structure, which comprises reinforced concrete beams and slabs into pre-determined 10 tonne sections. Water is used throughout the cutting processes as a lubricant for the diamond cutting blades and wire and also as a means of dust suppression, but by doing so, solids are taken into suspension. During the cutting process, in total four wire saws are utilised, creating up to 1,920 litres of waste water per hour.

In line with guidelines set by the Environment Agency (EA), EMDD is well aware of its responsibilities to treat silt laden water prior to discharge. In autumn last year, EMDD turned to Siltbuster for a solution to its dirty water problems. After reviewing the main issues on site – specifically the predicted volumes of slurry that might be produced and the weight restriction on the existing floor slab – it was decided the HB10 unit was most suitable for the project in question.

The HB10 stills the incoming waters and routes it upwards between a set of inclined plates. Fine particles settle onto the plates and slide down to the base for collection, while treated water flows to an outlet weir. The Siltbuster settlement unit offers a large effective settling area on a small footprint, making it ideal for a cramped site such as New Street station