A brownfield site is defined as "previously developed land" that has the potential for being redeveloped. It is often (but not always) land that has been used for industrial and commercial purposes, is now derelict and possibly contaminated.
All brownfield sites need to be assessed by an experienced environmental consultant before they can be redeveloped. This involves an analysis of the soil, groundwater and surface water through testing for hazardous compounds, and ensures that appropriate measures are taken to reduce identified risks and liabilities.
Remediation of a brownfield site is the removal of significant risks to future users and 3rd parties from all known contaminants to levels considered safe for human health and the environment.
Due to the sites historical use in the automotive industry, there are a variety of contaminants from its operation, including oils, fuels, degreasants and asbestos.
In soils – metals, hydrocarbons (from fuels such as heating oils, diesels), TCE (Trichloroethylene – commonly used as a a degreaser for metal parts) and asbestos.
In groundwater – hydrocarbons (from fuels) and TCE.
The Health and Safety Executive for Northern Ireland (HSENI) is the lead body responsible for the promotion and enforcement of workplace health and safety standards in Northern Ireland. On the Visteon project their primary focus will be to ensure that risks to the health and safety of workers, visitors and members of the public effectively controlled through announced site inspections.
Health and Safety Executive for Northern Ireland, 83 Ladas Drive, Belfast, BT6 9FR
T: 028 9024 3249
The Northern Ireland Environment Agency (NIEA) is an executive agency who work to protec, conserve and promote the natural environment and built heritage of Northern Ireland.
They will be concerned with being satisfied that the Visteon development site has been cleared of contaminants left over from the previous factory which could have a harmful impact on the local environment. NIEA will also be monitoring how waste materials are treated on-site and how they are being disposed of off-site.
Radius' Contractor will be required to submit evidence in a detailed report, produced by an independent consultant, to NIEA confirming that the site has been cleared as stipulated in the approved remediation strategy.
Northern Ireland Environment Agency, Klondyke Building, Cromac Avenue, Gasworks Business Park, Belfast, BT7 2JA
T: Pollution Incident Line 0800 807060 / Waste Management Licensing Team 02890569353
Belfast City Council Environmental Health (BCC EH) is responsible for carrying out measures designed to protect public health, including the adminstration and enforcement of environmental health legislation.
They will be concerned with being satisfied that the Visteon development site has been cleared of contaminants, left over from the previous factory which could have a harmful impact on the new residents as well as the general public.
Radius' Contractor will be required to submit evidence in a detailed report, produced by an independent consultant, to BCC EH confirming that the site has been cleared as stipulated in the approved remediation strategy.
Belfast Cityt Council, Environmental Health Services, Cecil Ward Bulding, 4-10 Linenhall Street, Belfast, BT2 8PB
T: 028 9027 0428
Radius also has a responsibility to ensure that the development site has been remediated, and as such has appointed its own specialist consultants who will undertake a review of the Contractor's detailed reports before they are submitted to the regulatory bodies for approval.
The groundwater contamination on site is being routinely monitored for Radius by WYG and has not impacted any private drinking water supplies. Mains drinking water in the area is supplied by surface water reservoirs and is therefore completelt unaffected by the site.
The investigations, risk assessment and remediation design works have been undertaken in line with Environment Agency Document CLR 11 – Model procedures for Land Contamination. This is the industry best practice guidance for the UK for assessing and remediating contaminated sites.
These works have been ongoing since 2006, with eight extensive reports produced including results of site investigations, sampling and chemical laboratory testing of soil and groundwater samples at a range of depths throughout the entire site. This has included:
The investigation undertaken has been very comprehensive and beyond the British Standard guidance on density. The reason for the comprehensive assessment is to fully understand risks and provide confidence on the methodology and remediation strategy.
The reports prepared by WYG have been subject to independent review by environmental experts both within NIEA and Belfast City Council’s Environmental Health Department.
All the high risk asbestos that was in the factory building was safely removed prior to demolition and removed from site under license. The asbestos removal from the building was undertaken under controlled conditions and monitored.
The asbestos remaining on site is present within the soils under the former building location and is predominantly bound in cement. It is not known exactly where it came from. It is known that it has been there a long time and was there before the last building was built. It is likely that it is associated with the various phases of construction of the Visteon factory where the old buildings would have been demolished to allow construction of the newer ones. This is a typical occurrence on brownfield sites.
All asbestos in the factory building was removed before the building was demolished. This was undertaken under controlled conditions. It was monitored during the removal and monitoring did not identify asbestos fibre release to air that would have caused exposure to local residents.
This was regulated by the HSE and all appropriate certificates and clearance certificates issued.
The majority of asbestos present in soils at the Visteon site is low risk fragments of asbestos bound in cement. This form of asbestos is present in a large number of buildings in Belfast, including in cement roof tiles, corrugated panelling and guttering.
A capping layer is the placement of clean material (soil and stone) on top of contaminated soils. The capping layer at the Visteon site will be a minimum of 0.8m thick. A capping layer prevents contact with the underlying soil and provides a clean soil for growing vegetables, grass and plants.
We identified that in the phase following demolition works, very low levels and sporadic asbestos fragments were present in the soils on this site. This would not be uncommon in brownfield sites throughout NI. The fact that asbestos was present had been identified during the initial investigations and the information made available to Belfast City Council and Northern Ireland Environment Agency. However the investigation following the demolition works found that the fragments are present over a wider area. We have not found any additional levels of asbestos than earlier investigations had suggested and the recent findings have now been updated in the proposed remediation strategy which was submitted to Belfast City Council Planning Department.
The works undertaken by Radius will regenerate and remediate the site, thereby reducing the risks posed by the site, as well as significantly improving and enhancing environmental conditions.
An asbestos risk assessment to current best practice guidance has been completed and identified low risks both for the future construction workers and low risk to off-site residential users, during the construction works. Asbestos is only a risk when it is air borne. Significant air monitoring for asbestos has been completed across the site to assess background levels during its current condition and during the demolition and investigation works. The monitoring to date has not detected asbestos in the air above detection limits. There is ongoing monitoring of air quality on the site boundary for asbestos and should asbestos be detected that may pose a risk, works will be halted, Belfast City Council, Northern Ireland Environment Agency (NIEA) and Health and Safety Executive (HSE) will be notified immediately and mitigation measures implemented to manage any risks.
With regard to general soil and groundwater contamination the detailed and extensive risk assessments completed to date have determined there is no risk to off site residents and other properties. This is continually monitored and updated. Again these risk assessment reports are undertaken in line with industry best practice guidance and have been reviewed extensively by experts in NIEA, Belfast City Council and by independent consultants.
Asbestos will not become air borne if it is wet. Asbestos air monitoring has been completed in the summer under dry conditions during ground disturbance works and as outlined above did not identify asbestos to be present in air.
Belfast City Council and HSE have been consulted throughout the process and have all the technical data that we have gained on the site. Based on the assessments to date it is safe to stay in the houses adjacent to the site. WYGs monitoring shows that any contamination present at the site has not migrated to adjacent houses and properties. As stated before, the remediation works will clean up the site, make it safe and improve the overall environmental condition of this derelict brownfield site. The largest risk – the old factory buildings and tanks have already been removed safely.
As outlined above contamination associated with the site is located within the site boundary and does not impact adjacent properties. Once remediation has been undertaken and validated there will be no risks to the proposed new houses to be built on the Visteon site.
Current legislation and guidance do not require the site to be remediated to pristine or greenfield standards. The remediation of contamination uses a term called a “risk based approach.” This requires all contamination to be remediated so that there are no risks to human health or risk of pollution to the environment.
A number of remediation techniques will be completed at the Visteon site to remediate the different contaminants present as follows:
All gardens and landscaped areas in the development will have a capping layer.
All houses and buildings will be provided with a membrane in the floor which will stop any potential contaminants, gases or contaminated vapours from entering the houses or other buildings from the contaminated soils or contaminated groundwater below. This membrane is a common occurrence during residential construction.
Any soils or water with free product or oil contamination will be excavated and removed from site. These are present on the site where the factory tanks were located.
Contaminated groundwater in shallow soils and the Sandstone bedrock aquifer, is being continually monitored. It is not currently causing risks to human health or the environment. However, should contamination concentrations increase then remediation will be completed by injecting treatments that will lower contamination concentrations.
You can contact Radius via www.radiusvisteonregeneration.com or alternatively email us on firstname.lastname@example.org or telephone 0330 123 0888, and we will respond within 48 hours during the working week.
This is not expected due to the extensive number of tests and investigations completed to date but if during the construction works any new contamination is identified, all works will cease immediately and the relevant statutory consultees will be notified. The contamination will be assessed in line with best practice and remediated in consultation and with the approval of Belfast City Council and NIEA.
The regulatory bodies, Belfast City Council and NIEA have been consulted at each stage of the works agreeing each step of the investigation, risk assessment and remediation approach. All reports have been submitted to the regulatory bodies via the planning process for consultation.