Accelerated growth in rail infrastructure and trackside developments pose a rising risk of exposure to hidden, harmful contaminates. Jon Clements, Commercial Director of Ensafe Consultants highlights how to deal with current contaminated land challenges
Many new development projects are being constructed on brownfield land in a move to fast track rail projects and improve infrastructure alongside key transport routes.
Ensafe Consultants have extensive experience collaborating regularly on rail sector projects and meeting compliant criteria for Network Rail, providing industry insight into potential pitfalls facing developers when utilising previously developed brownfield land adjacent to the rail network.
As infrastructure projects, including HS2 continue to gather pace, I will use this article to offer some advice on what safety steps should be taken when planning and undertaking these types of projects.
It is critical that designated development sites, alongside surrounding areas allocated for important infrastructure implementation, are inspected thoroughly by sector specialists to initially identify and eradicate any potential risks rising from contaminated land. The need to inspect potentially contaminated land is rapidly rising within the industry.
There has been a spike in requests for specialised contaminated land surveys and remediation strategies to assist with major infrastructure projects within the rail sector. We are seeing a massive rise in enquiries for contaminated land specialised survey services because greenfield land is very difficult to develop due to restrictive planning legislation. Therefore, brownfield land development is expanding as demand grows.
Notably inner cities are seeing more and more redevelopment because they are dead spaces. Councils and authorities are trying to encourage people to use those centres of urban conurbations. However, they’re potentially contaminated because of heavy industry and previous usage. There are all sorts of derelict buildings, structures and areas designated for development, but issues arise around the fact the ground is contaminated and needs cleaning before it can be utilised for construction and infrastructure implementation.
So, the growth is massive. We’ve got these very large infrastructure projects, like HS2, and all of the new rail links routed through the country that are running out through cities also. HS2 starts in London, runs out from Euston and they’re trying to build a two-lane railway line that flows over pretty much solely brownfield for the first ten to twelve miles of that allocated area.
As such, all of the buildings in the way are coming down, and all of that ground therefore needs to be tested. Any material on site, if it is contaminated, will then need to be remediated – it’s a huge project. Each project where anything is replaced, or where work is carried out on existing land/building sites and railways, there is the potential to encounter contamination issues. Asbestos can be detected in previously developed land due to several factors including buried waste, particularly on the railway. In previous times the brakes of trains were lined with asbestos and when trains braked asbestos fibres would come off those brakes and land on the trackside on the ballast.
Over time when track replacement improvements were undertaken the ballast would be dug up and all of the material that had been thrown alongside the railway and new ballast that had been put down, then got further contaminated. The ballast that was cast aside would be compacted over time and other materials put onto it so it started to bury into the ground, creating additional areas that could contain contaminates.
With the recent slowdown in the construction market there is a growing trend to try and clean existing buildings or use existing land because greenfield is difficult to develop and there is a requirement to locate these new projects near to infrastructure, like key railway stations and transport routes.
So, inner-city and land adjacent to major networks, like the railway, is obviously attractive however the downside is, because it has been built on previously and used before, there is a fair chance that it could have some form of contamination in it.
Land is legally defined as ‘contaminated land’ where substances are causing or could cause:
• Significant harm to people, property or protected species
• Significant pollution of surface waters (i.e. rivers and lakes) or groundwater
• Harm to people as a result of radioactivity.
Contaminates could include asbestos, heavy metals, such as arsenic, cadmium, carbons and lead alongside oils, tars, chemical substances, gases or radioactive substances. If you want to dig in the ground and conduct trackside developments, then you need to make sure you are not going to disturb this material. Ultimately if there are contaminates in the ground you need to know they are there and then you have to ensure they are safely consigned to landfill.
The issue is how to establish whether an area is contaminated or not. To ensure compliance the process would be:
• Undertake a contaminated land survey – including digging of trial bore pits to extract core samples, which are sent to an accredited laboratory
• Samples undergo a suite of testing to identify what materials are present and a strategy implemented to be able to remediate the ground.
However, there is a grey area when it comes to dealing with contaminated land and I would welcome legislation to bring some clarity to the sector. One of the challenges currently is there isn’t a piece of legislation that actually states what the process should be, so it’s more a discussion and acting prudently.
There are a number of white papers and legislative drafts that are going through statute currently. We would work to those principals but ultimately it would be good housekeeping to identify what contaminates are present and agree what can be done with them. However, we are also commercial and the cost of putting it back in the ground or consigning it to landfill is very expensive. But sometimes that material cannot then be used again because it’s not environmentally sound and you have no choice.
The advice to contractors undertaking work on construction sites would be to integrate contamination checks early on to ensure there is no delay and minimum disruption to the project’s programme of works. Then it is a question of getting all necessary safety measures in place.
It is essential to set up a demarcation or an area of exclusion, which is the work area. Whilst the survey is being undertaken you have to ensure there are no elevated fibre counts, particularly of asbestos, in the air. The process needs to be managed to ensure all of the works undertaken are done safely and legally so that everybody is safeguarded whilst that work is carried out.
At the end of it you would have someone, like Ensafe Consultants, who would implement the legal sign off. This would entail outlining the materials that were contaminated, the process undertaken, and the specification of any material that had to be consigned and where it has gone.
Providing procedural processes and sign off then reassures anybody that comes after you, the rail workers, road builders, and house builders (anyone who wants to work in the ground) that they are safe to do so.
Compliance is critical when working within this specialised sector including rail projects. As demonstrated when King’s Cross Station developers enlisted Ensafe’s expertise for a multimillion-pound project.
One of the most important stations in the capital, London’s King’s Cross required Ensafe’s experts to assist with a £30 million programme of works. We were contracted to project manage the full dismantling and associated asbestos removal works to both train shed roofs situated at King’s Cross railway station.
This significant and prestigious project was undertaken when we were appointed directly by the programme’s Principal Contractor, Kier Construction. The company enlisted Ensafe to act as their competent asbestos consultants assigned to coordinate the asbestos project management throughout the programme of works. The major works at this landmark site involved the day-to-day practical management of all elements of this complex roof removal project, which we successfully completed.
Certain types of asbestos can be screened in specialist heavy plant machines and the asbestos removed so soil can be used again on site. Such was the case at Stanton Cross, a major mixed-use development for Wellingborough in Northamptonshire. The Midland Mainline runs through part of the development and a potential for asbestos contaminated land and buildings was identified.
Originally engaged by Principal Contractor Galliford Try to carry out a pre demolition survey, Ensafe then went on to assist with:
• Project Management of removal of ACM’s (asbestos containing materials)
• Project Management of the demolition of old trackside buildings
• Soil remediation.
Ensafe managed the screening of around 35,000 tonnes of soil onsite. Once we were happy that the soil was within safe limits it was then reused in the construction of the development’s infrastructure. Instead of paying to excavate it and then send it to landfill, we cleaned it and they were able to use that again on site.
Similar such sites can contain contaminates, which pose major health risks, therefore it is essential an accredited organisation undertake a suite of environmental testing to look for harmful contaminates.
We would conduct a full study of the designated development area and advise on any contamination. When working on large projects alongside major railway routes, if there are buildings within the designated construction site, it’s essential to undertake surveys to identify deleterious materials, specifically asbestos, within buildings.
The process would be to put a methodology together to remove any asbestos and manage the safe demolition of those structures, then to clean the surrounding grounds to allow new buildings to be erected or new railways, road and infrastructure to be laid.
The process is:
• To find what’s in the ground
• To identify it
• To strategise what needs to be done to remediate it.
The entire process, from identifying a problem, to having the solution and then being able to put space in the ground can take several weeks, depending on contaminates that are discovered. It is quite a fast process once work gets underway. During a recent project we worked on we were able to successfully screen circa 250 tonnes of soil a day. It is key however to get all necessary safety measures in place including a demarcation area of exclusion and ensure all works undertaken are done safely and legally so everybody is safeguarded when the necessary work is carried out.
With providers of such specialised survey services increasingly in demand, it is essential to enlist an accredited and experienced organisation for such operations. Ultimately if you want to work in the ground you need specialists to tell you if you are good to go or give you a strategy to make sure you don’t disturb any contaminates, you don’t break the legislation, and everyone is safe.
Jon Clements is Commercial Director of Ensafe Consultants. Contact the company on 01604 878190 or via email at [email protected] You can also visit the website at www.ensafe.co.uk