Homes on one of Wales’ most polluted streets are set to be knocked down next month as part of a plan to improve air quality.

Caerphilly County Borough Council has lodged a planning application to demolish 23 properties on the A472 in Hafodyrynys, near Crumlin, where nitrogen dioxide levels have been recorded as the highest in the UK outside central London.

As part of a plan to meet air quality requirements in the quickest time possible, the council bought the houses which are to be demolished for 50% above the market rate to ensure residents did not lose out financially.

The Welsh Government, which is contributing funding towards the £6.7m scheme, issued a direction to the council in 2019 for the homes to be knocked down “without delay”, with a deadline of December this year.

Now a planning application setting out the plans says demolition work is expected to start on Tuesday, May 18.

Demolition work and site clearance is expected to take 14 weeks, and is due to be completed by August 27.

It is proposed that demolition of the properties will take place first, before work to build a re-aligned footway.

“The majority of properties that are to be demolished form a continuous block of terrace houses to the south of Hafodyrynys Road, comprising numbers 1 to 20 Woodside Terrace,” a planning application says.

“These properties are of three-storey construction with basements.

“In addition, there is a detached property – Yr Adfa – and a pair of semi-detached properties – number 1 and 2 Woodside Shops.”

It is proposed to give the contractor two access options on to the site to demolish the homes.

One would require creating a temporary access road from a layby, and the felling of several trees, while the second access would be from a layby next to Yr Adfa.

The work will take place between 8am and 6pm Monday to Friday, and 8am to 1pm on Saturdays.

The plan to knock down homes and re-align the footway is expected to help the area meet air quality requirements by 2022.

It is intended the scheme will remove the ‘street canyon’ effect in the area, reducing pollution concentrations and improving air quality.