In response to Ian West’s recent letter in the Salisbury Journal (December 14), we would like to address and correct any concerns regarding the ‘dumping of 1.25 million cubic metres of spoil…causing a permanent blight on the landscape’ as part of our plans.

All the excavated material from the tunnel boring operation will be predominantly chalk and will be treated, and excess water will be removed.

In keeping with our cut and fill methodology and sustainable practices, the material will be retained on site to avoid transportation off site and the unnecessary export and import of material, representing significant carbon reduction and cost efficiency savings.

The material will then be re-used for landscaping and the creation of new areas of chalk grassland, including an entirely new area adjacent to Parsonage Down Nature Reserve (north of Winterbourne Stoke).

Far from ‘creating a looming presence’ and ‘associated noise and air pollution’ these chalkland areas will integrate into the landscape and increase biodiversity by creating new wildlife habitats.

Many different options and sites were considered for placing tunnel arisings, the site chosen provides the opportunity to sympathetically place material hidden within a rolling landscape, with visible gently sloped embankments to enable the bridging of the sensitive Till Valley.

Located to the north of Winterbourne Stoke material will be placed to blend in and maintain the character of the area.

In total we will be creating more than 300 acres of new chalk grassland, and enabling the isolated area around Stonehenge to be reconnected to Salisbury Plain, one of the world’s largest areas of chalk grassland.

It’s also worth pointing out that the tunnel construction method for the A303 Stonehenge scheme will prevent any damage to the landscape.

A tunnel boring machine, similar to the type of machine used to construct tunnels for major infrastructure projects all over the world, will be specially designed for the exact chalk ground conditions within the World Heritage Site. 

The proposed tunnel, as part of the A303 Stonehenge scheme, is a ‘twin-bore’ tunnel – two tunnels, each carrying two lanes of traffic in each direction and connected with safety passages approximately every 150 metres.

National Highways’ contractors will be using a specialist tunnelling machine called a tunnel boring machine (TBM) which will dig the tunnel without disturbing the ground directly above. 

The tunnel will also be further away from the monument than the current road – more than 200 metres away and up to 40 metres underground – and by burying the road, our aim is to reunite the World Heritage Site landscape. 

This is a very sophisticated machine which will be specially designed for the exact ground conditions we'll be going through.

Its design has been informed by extensive geotechnical surveys and groundwater monitoring, all included in the Environmental Impact Assessment submitted as part of the Development Consent Order application.

This type of tunnel boring technology has been used for many years around the world, notably on the Crossrail tunnels in the middle of London.

For anyone wanting further information on the scheme, I would also recommend checking out our scheme web page at nationalhighways.co.uk/our-roads/a303-stonehenge/about-the-scheme.

David Bullock

A303 Stonehenge Project Director, National Highways

Send letters by email to newsdesk@salisburyjournal.co.uk or by post to Editor, Salisbury Journal, Suite B (Ground Floor), Milford House, Milford Street, Salisbury, SP1 2BP.