A dedicated advisor has been appointed to oversee how the island deals with the issue of coal tar.

Coal tar, a by-product from the Douglas Gas Works, was widely used in road construction up to the 1980s, but is now considered a hazardous material that’s classified as carcinogenic.

It presents no risk to the public or the environment while it is in the highway but when the material is removed from the road construction, creating dust particles, it is deemed a hazard - although even then the risk to the public is minimal.

Around 20 highways projects have had to be postponed as a result of finding coal tar present.

One such project is the construction of a new roundabout at Balthane Corner which will finally create a by-pass around the village of Ballasalla.

Work is due to start on the roundabout in early 2026 in a scheme which is expected to take between six and nine months to complete.

Asphalt Waste Containing Coal Tar (AWCCT) cannot currently be disposed of on-island as there is no facility available to dispose of hazardous waste.

Around 1,000 tonnes of coal tar waste is currently stored in temporary licensed locations across the island.

The Department of Infrastructure’s preferred solution is to re-use the material by mixing it with other stable agents such as cement or bitumen and then using in the lower layers of new road construction.

This requires a specialist mixing plant to carry out the process.

At Balthane it is proposed to use cement to hydraulically bind the coal tar for use as the sub-base layer of the new roundabout and road. Detailed mix designs and specifications are being prepare by UK specialists.

The DoI is currently drawing up a planning application to develop an existing facility for the temporary storage of coal tar waste.

Once sufficient material is stored it will be processed and incorporated into a highway construction project in the same way as proposed for the Ballasalla bypass roundabout.

Some £40,000 of funding has been approved by Treasury to appoint a dedicated coal tar advisor who is is now in post.

Their remit is specifically to advise the DoI on treatment for the Ballasalla project, writing specifications and supporting the department and contractor in waste licensing.

Infrastructure Minister Dr Michelle Haywood said: ‘DoI have a specialist engineer advising them on which method would be most appropriate for treating the asphalt containing coal tar waste that we have in storage.

‘There are several possible methods and this is the first time the island has started to deal with the coal tar waste, so it's a very sensible step to get expert advice to make sure that what we do is appropriate and the end product can be safely reused as we have planned.’

A one-way system affecting access to the airport is to be introduced during construction of the roundabout at Balthane - and motorists have been warned to face months of disruption.