Preparatory works began in September and the process of remediating the soil will begin this month.

The site is now being used exclusively by contractor Sanctus Ltd - which has worked on numerous brownfield and infrastructure projects across the UK- and local people are being reminded that access to the site is no longer permitted.

Councillor Tony Gurney, cabinet member for Green Environment and Economy, said: “We are aware that members of the public, particularly dog walkers, are still using the site and we would like to remind them that this is now a construction site and access is not permitted.

“We are delighted that Sanctus is now on site and beginning the process of remediating the site. While we know that the site has a long legacy of industrial use, a portion of the site was remediated to residential standards in 2011, and it is encouraging that the remainder of the site will now be brought up to the same standards.

“We are very much taking a belt and braces approach on the site as public safety is our absolute priority.”

The vast site is central to North Ayrshire Council’s ambitious £170 million regeneration plans for Ardrossan.

The site will be the location for the new Ardrossan Coastal Quarter, including the new Community Campus.

Sanctus will follow a detailed plan drawn up by the council and environmental consultants EnviroCentre. The remedial works will be licensed by SEPA.

The process will last just under a year and will incorporate a range of environmental improvement measures which will ensure the land is ready to build on next year.

The remediation works incorporate treatment of soil and groundwater to meet the highest standard according to UK Government Environmental Guidelines.

This means they will ensure that the land is fit for residential use with gardens – which is the strictest criteria laid out within these guidelines.

In addition, it incorporates stringent criteria for addressing risk of pollution to the water environment.

Sanctus Ltd has extensive experience in carrying out remediation of the contaminant types present at Ardrossan North Shore.