Blending in with MBT and IVC
Blue skies and sunshine greeted AFOR members when they arrived at BAM Nuttall's offices at Waterbeach in Cambridgeshire. This visit kindly hosted by the BAM Nuttall team was designed to show members both the almost completed Mechanical and Biological treatment facility and the Wasteology in-vessel composting plant.

Innovative
After a brief introduction from Mark Davenport, Managing Director of the Donarbon Group, which also includes Dickerson and Frimstone, we were given an introduction to the history behind the PFI contract which resulted in the construction of the MBT facility. Donarbon secured last year the 28 year Cambridgeshire County Council PFI contract valued at £730 million through their innovative solution of a state-of-the-art MBT facility costing in excess of £41 million.

After splitting the 50 delegates into two groups one for each facility, we set off to see the respective sites.

What struck me as a first impression about the MBT facility was how well it blended in with its surrounding environment. With planning being a key issue in the construction of such a significant building the shape and colouring had to be as inconspicuous as possible, this has been achieved.

The integration of offices and an education centre and viewing area within the main building ensures that the provision of ongoing training and learning objectives in particular for schools will be met in the future.

On entering the processing area we were able to view close up the impressive array of conveyors, bag splitters trommel and star screens and an assortment of separating equipment. The conveyors and all this equipment was sourced from a German company, Komptech who specialise in the waste sector, the machinery alone came to a staggering £7.8 million.

Capacity
The plant has a design capacity of 170,000 tonnes per annum and is designed to process up to 24 tonnes of residual waste per hour. Staffing levels are remarkably low with an anticipated staffing team of 14 working two eight hour shifts.

The input residual waste has up to 80% of the inputs recovered in the form of recyclates such as ferrous and non ferrous metals, plastics and aggregates leaving behind the organic fraction of the waste stream. This is pulverised into a mash which is then transported by conveyor through to the composting halls.

Composting halls
Until you experience firsthand the size of this building from within, it is difficult to comprehend the scale of both the building but also the Kelag compost turning machine. This resembles a machine from a science fiction film with its twin large wheel buckets suspended on an overhead gantry; this machine is at the heart of the process as it moves the compost like output (CLO) over seven weeks from one end of the hall to the other.

Each of the two composting halls has an impressive dimension of 180m long by 35 metres wide; this is filled to a depth of 3.5 metres at the start of the process. After an excellent lunch, provided courtesy of BAM Nuttall, our group was driven by Landrover to the nearby in-vessel composting facility.

This complex which is close to completion comprises of a reception building where the incoming green and food waste is shredded prior to filling into one of the 20 new tunnels. Donarbon have been using Wasteology technology for the last six years and are well versed in its operation. The new site which is designed to treat 60k tonnes of input per annum will be producing a high quality PAS 100 and Quality Protocol compliant compost which will be used predominantly in the agriculture and landscape markets.

You could not fail to be impressed with the level of investment and commitment shown by Donarbon in partnership with Cambridgeshire County Council. Significant thought has been given to the provision of a facility which will provide a versatile solution to the County's waste well into the future.
Thank you to all the Donarbon and BAM Nuttall staff for being so patient with us and answering all the tricky questions!

Article courtesy of Organics Recycling - autumn 2009

Further Info
Peter Bishop - Head of Public Relations & Corporate Communication
BAM Nuttall Limited
St James House, Knoll Road, Camberley,
Surrey GU15 3XW
Tel: 01276 63484
Fax:01276 66060
peter.bishop@bamnuttall.co.uk