Excavated material removed from the International Finance Centre site (FOI)

Request

Could you please advise me how the excavated material removed from Building 5 at the International Finance Centre site was categorised, segregated, treated and disposed of at La Collette?

Response

The area of reclaimed land at the International Finance Centre, known as building 5 (IFC 5) was divided up on a set of site drawings into a series of 10 meter grid squares over the whole of the excavation area. Each grid square on these drawing was given an individual area code which was used to reference each area of the soil samples that were taken from the site. Some 61 plus soil tests were carried out initially for this site in order to create a Ground Contamination Assessment Report. Additional soil testing was requested by the Department for Infrastructure (DFI) later during the excavation when additional quantities of soil, not previously tested, had to be excavated.

The soil testing was carried out for the main contractor by a United Kingdom Accreditation Service (UKAS) Laboratory. The soil samples were tested for a large number of contaminates, leachates and asbestos fibres as needed to meet the requirements for testing to the European Waste Acceptance Criteria (WAC) for landfill sites.

The soil sample test results were received from the laboratory by a specialist waste soil consultant, who assessed the test results against the WAC standards and the European Waste Classification and technical guidance (WM3). The subsequent report issued to the Jersey Development Company (JDC), the appointed IFC5 contractors, the Waste Regulator and DFI, stated that the results had identified areas of soil to be excavated, as exceeding the WAC limits for the reclamation tip head at La Collette. The soil test results identified that some excavated soil within certain grid squares would have to be received at La Collette as contaminated waste with five of the grid squares having to be classified and consigned to La Collette as hazardous waste and therefore requiring encapsulation within the various lined cells that the department had previously built for these types of wastes.

Due to a number of the test results identifying waste that could not be deposited at the tip head DFI, in consultation with the JDC, the Health and Safety Inspectorate and the Waste Regulator, determined that all of the excavated soil from the various grid square locations must be encapsulated within the lined cells.

To ensure that the waste soil from each grid square was able to be identified separately and accurately, the excavation site was regularly resurveyed and marked out with the designated grid square markings corresponding to the excavation plan. The reference points and markings allowed the machine operators and site supervisors to know which zone they were digging from 
at any given time and what reference number must be written on each of the load tickets that accompanied the vehicles delivering to La Collette.

During the excavation of the waste soil a specialist asbestos removal company was engaged on site to carry out a visual inspection of the excavation area looking for asbestos containing materials (ACMs). If licenced ACMs were identified they would stop the excavation in that area and remove the licensed ACM from the soil and secure it in a bag and locked skip for consignment to the asbestos cell at La Collette. Once this had been carried out any large items of material such as boulders, large items of concrete or pieces of metal that could cause damage to the cell liners at La Collette were removed from the excavated soil and treated and disposed of separately.

Prior to leaving the IFC 5 site all haulage vehicles had their loads sheeted over and then driven through a wheel wash to remove any soil that may be clinging to the lorry sides or wheels. When the vehicle arrived at La Collette Reclamation site the driver was meet by a DFI reception site advisor (RSA) who checked the load consignment sheet details for the waste classification and grid square code. Once the RSA was satisfied that the load was clearly identified and meant to be received at La Collette the driver was directed to the appropriate cell or reception area. At each of the reception areas the vehicle load ticket was again checked by the site supervisor who then directed the load to a de-sheeting station and then in to the designated tipping area or cell. Once empty the external body and wheels of the vehicle were again washed and inspected for any external soil before the vehicle was directed back to the site exit and back to the IFC 5 site via the weighbridge.

As each load of contaminated soil was tipped within a designated cell the soil was dampened down with water spray to prevent dust release, the soil was compacted into position by a large excavator then covered over with a close woven fabric and finally a covering layer of inert material. All of this containment work was carried out under strict site supervision and airborne monitoring by an independent asbestos consultant.