IT cost £15m, employs more than 100 people and plays a vital environmental role.

But most people who drive past every day have never seen its cavernous interior and have no idea what goes on behind the anonymous grey walls.

The only clue is a small sign bearing the name SCA, one of the UK’s biggest recycling firms.

Opened by Olympic athlete Roger Black in 2009, every year the Materials Recycling Facility (MRF) overlooking the A326 near Totton handles up to 200,000 tonnes of commercial and domestic waste that might otherwise go to landfill from as far afield as Plymouth, Cardiff and Exeter.

Inside the huge, hangar-like building the waste is sorted by man and machine. A non-stop river of rubbish flows in on fast-moving conveyor belts that operate 24 hours a day, six days a week. The material is continually divided and sub-divided to separate paper from plastic, glass from metal.

The building is equipped with laser beams, magnets and air jets to ensure items are identified, separated, and sent to the right place.

The end result: individual mountains of paper, plastic and other materials that can be used again.

The whole process is run from a small control room. SCA spent £15m o n installing American-made recycling equipment. It is already operating at between 80 and 90 per cent capacity and the figure is set to rise even further.

Simon Barnes, recycling business development manager, said the facility even has an education room to: “Inform visitors of the key issues surrounding recycling today, such as the savings that can be made by reusing materials.

We’re encouraging people to see materials as a re-source, rather t h a n waste.