Final plans to demolish houses on one of Wales’ most polluted streets in a bid to improve air quality have been backed by the Welsh Government.

Caerphilly County Borough Council has submitted a revised version of its final plan to tackle air pollution on the A472 in Hafodyrynys, where nitrogen dioxide levels have been recorded as the highest in the UK outside central London.

The proposal will see the council buy 23 properties for 50% above the market rate to ensure residents do not lose out financially.

Nineteen of the 23 homes to be demolished have already been bought by the council, with sales agreed for the remaining four.

Welsh Government has pledged funding for the project, which is estimated to cost a total of £6.7 million.

Lesley Griffiths MS, minister for environment, energy and rural affairs, said the council’s submission of a revised plan was a “significant final step” towards meeting air quality targets.

“I commend the authority for meeting challenging timescales to deliver this,” Ms Griffiths said.

“The updated assessment has established, with greater confidence, the preferred option is likely to achieve compliance with nitrogen dioxide limit values in the soonest time possible.

“This assessment has been supported by our independent expert review panel.”

The plan will see all residents in the affected properties leave their homes before the end of this year, with demolition work planned to start at the beginning of 2021.

Air quality requirements will be met by 2022 under the plan, more quickly than an alternative approach which relied on vehicle emissions improving without further intervention.

The scheme will remove the ‘street canyon’ effect in the area, reducing pollution concentrations, and will see residents in the properties worst affected by poor air relocated.

Cllr Philippa Marsden, leader of the council, said the proposals “really are a ‘win-win’ for all concerned”.

“Demolition of the properties will allow us to achieve air quality compliance in the shortest possible timeframe and the residents affected have been offered a fair financial settlement,” Cllr Marsden said.

“It has been a long and complex process to arrive at this stage and I would like to thank the community for their co-operation and feedback in helping us reach this conclusion.”