More than 20 Department of Infrastructure (DoI) schemes across the island are currently being delayed because of the ongoing issue of coal tar waste, Infrastructure Minister Dr Michelle Haywood has confirmed.

Coal tar, historically used in road surfacing, is categorised as hazardous waste and cannot be disposed of in landfill.

There are no licensed facilities available to store any more coal tar, leaving the DoI unable to excavate roads containing the material until a safe processing method is available.

Two of the most significant projects affected are in the south, the long-awaited Balthane roundabout and Ballasalla bypass scheme, which has already faced disruption due to persistent flooding and failed drainage.

Speaking in the House of Keys on Tuesday morning, Dr Haywood said specialist advisers had now identified a solution that would allow the department to safely reuse large quantities of coal tar on the Balthane project.

She said: ‘The Department will reuse approximately 1,100 tonnes of asphalt waste containing coal tar within the completion of Ballasalla bypass and the construction of the new Balthane roundabout.

‘The coal tar waste material will be processed at Turkeylands Quarry, a licenced facility with strict environmental controls, before being incorporated into a bound sub-base layer beneath the road.’

Dr Haywood explained that the material would be ‘fully encapsulated within a stabilised cement, bound or foamed bitumen mix and sealed under multiple asphalt layers and a bitumen spray, creating a low-permeability structure that greatly reduces water ingress and leachate risk.’

She said the approach was supported by site investigations, which ‘identified no groundwater within a metre of the finished road level,’ and that ‘additional safeguards such as dilution with virgin aggregates, rapid coverage after placement and positive drainage further minimises any environmental risk, ensuring robust containment that protects groundwater and surrounding ecosystems.’

All handling and storage will take place under hazardous waste regulations with impermeable hardstanding, controlled drainage and monitoring under a disposal licence issued by DEFA. Dust suppression and PPE for operatives will also be required.

Dr Haywood added: ‘At the moment, we have so much coal tar waste stored that we do not have any more licensed facilities in which we can store it.

‘It is holding up more than 20 projects across the island where we cannot go and dig up roads because of the coal tar waste that’s underneath them, and we have nowhere to put it or any way of reprocessing it.’

Asked by Tim Glover, MHK for Arborby, Castletown and Malew, as to when construction of the new roundabout would begin, she said she anticipated works starting ‘somewhere next year,’ adding that the timetable must take into account TT and Southern 100 traffic restrictions.

The update comes amid renewed concern from Ballasalla residents about the worsening flooding at Balthane roundabout.

One resident recently reported being ‘unable to get home’ during heavy rainfall on November 12 due to both approaches becoming impassable.

A DoI spokesperson confirmed earlier this month that no permanent fix to the flooding will be possible until the new roundabout is built.

The bypass project is currently expected to start in early 2026 and take six to nine months to complete.