Over the years, SOCOTEC’s Contaminated Land Consultancy has been involved in a range of reclamation and redevelopment projects that have required the investigation of potentially contaminated sites, many of which are located on existing or former railway land. Contaminated land tends to be encountered through previous or current activities carried out on maintenance depots, stations, engineering works, stabling sidings and marshalling/goods yards, all of which can have a detrimental impact on the site’s occupants, workers and the surrounding environment – particularly during ongoing renovations, construction works and essential maintenance.
What kind of contaminants can be present on railway sites?
Railway environments are used for a host of different purposes, including fuel storage and handling, vehicle maintenance, waste disposal, demolition and chemical processing, many of which can produce unwanted material and contaminate the surrounding environment. Soil and ballast on railway sites may potentially be contaminated with hydrocarbons, coolants, solvents, asbestos-containing materials, cleaning chemicals, pesticides, polychlorinated biphenyls (PCBs) and contamination from ash/fill materials. Off-site contamination can also occur on railway sites via the migration of a liquid (including dissolved in groundwater), gas, vapours and even windblown dust.
How can you determine whether land on railway sites is contaminated?
Prior to any kind of construction or engineering works taking place on the railway, it is important to determine whether or not the land in question is actually contaminated and the level of risk that this poses. To identify this, the land in question should be assessed according to the following criteria:
- Environmental harm is being caused/there is a significant possibility of such harm being caused
- Significant pollution of land and/or controlled waters is being/is likely to be caused.
Investigatory works are required to identify whether there is a possible link between contaminant sources in the land itself and potential receptors in the surrounding environment that could be harmed or polluted. Once these have been identified, the appropriate control and risk mitigation measures may be applied to keep the level of risk posed by contaminants to a minimum.
How has SOCOTEC helped to assess for contaminated land on railway sites?
A recent rail-related project that SOCOTEC’s Contaminated Land Consultancy has been involved in was the management of a contamination risk caused by historical waste disposal on the site of a major infrastructure project. On the land in question, a road bridge was to be constructed surrounding a new railway station, improving traffic circulation and integrating the existing roads with the station in question.
By carrying out soil investigations and installing shallow and deep groundwater monitoring standpipes, SOCOTEC was able to carry out a full contamination assessment of the impacted area and help manage the risks during piling works for the construction of the bridge. The team was also able to obtain soil samples for waste classification and Waste Acceptance Criteria (WAC) testing, as well as a programme of pre, during and post-piling groundwater quality sampling, analysis and assessment.
Two mobile laboratories were set up on either side of the carriageway to undertake rapid chemical analysis of the soils during piling operations, with the groundwater produced during de-watering operations also being assessed for contamination. The laboratories provided hydrocarbon and metals data, which was used in water management and waste segregation and decision-making for the reuse of materials. Meanwhile, areas of buried wastes were remediated in partnership with SOCOTEC’s subcontractors.
By conducting an on-site analysis of groundwater and soils surrounding the area where the bridge was to be constructed and integrating this analysis with hour-by-hour advice and a remediation service, SOCOTEC’s Contaminated Land team was able to reduce turnaround times for sample analysis and the amount of soil taken off site as waste, minimising the risk associated with the contamination. This in turn ensured that the ongoing construction did not pose any risk to site staff, the general public and the surrounding environment.
How can SOCOTEC help?
SOCOTEC’s Consultancy can investigate and advise on contaminated land within a host of different environments (including the railway), offering such services as groundwater contamination investigations, waste management and environmental monitoring.
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