A MASSIVE concrete tunnel being built over the railway line at Gerrards Cross is around 90 per cent complete.

The development of a Tesco superstore directly over the railway line will soon start to take shape, with the completion date expected sometime in late summer.

Graeme Richards, the system and planning manager for Jackson Civil Engineering, is in charge of the project.

He said: "It is progressing well. It is quite a complicated tunnel. There are still some sections to finish."

Mr Richards has reassured concerned villagers that the Incinerator Bottom Ash Aggregate (IBAA) used in the project is safe and is commonly used in major developments after reports of smells coming from the aggregate.

Mr Richards said: "IBAA is used for construction and the environment agency have given it the go-ahead for us to use it here.

"It may be that passers-by see steam coming off the material but that steam is simply the water evaporating and it poses no health risks at all."