THE millionth cubic metre of chalk was laid close to the southern portal of HS2’s Chiltern tunnel in early September.
A total of 2.6 million cubic metres of the substance, which is being excavated during the creation of the tunnel, will be used to create one of the largest areas of chalk grassland in the Chiltern hills as the area is returned to nature. It will form part of a 1.27 square kilometre (314 acre) site also incorporating woodlands, wood pasture and wetlands.