The Donor Site was the former Maliphant Railway Sidings Site in Swansea. The site is being redeveloped for the new Hitachi Trains Servicing Facility (part of the electrification project for the South Wales Main Line).
The main contractor, Volker Fitzpatrick Rail, identified the need to excavate 44,000 tonnes of contaminated and uncontaminated soils from the site as part of the overall development. Volker Fitzpatrick set an environmental target to divert 90% of the material requiring offsite disposal away from landfill.
The Receiver Site was the former Alcoa Manufacturing Facility based on the Westfield Industrial Park Site in Waunarlwydd, Swansea. The Westfield Industrial Park is shown in Figure 2 below.
Several of the onsite buildings within the Alcoa Facility were unusable from a leasing point of view due to the presence of several existing machine pit voids (remaining from the previous manufacturing operations).
The landlord commissioned Ramboll Environ to prepare a specification for the ‘cleaning out’ and infilling of these voids. The specification for the infilling process required the use of suitable material in terms of chemical and physical properties.
The Treatment Hub was approached to provide suitable recycled material for infilling the ‘hot mill’ pit (the largest machine pit / void requiring infilling).
It was calculated that at least 6,000 tonnes of adequately ‘clean’ and geotechnically suitable material would be required to infill the hot mill pit. Previous works on the site involved the importation of locally recycled 6F2 at a cost of £16/tonne.
Based on the chemical and geotechnical specification for the required infill material (stipulated by Ramboll Environ) and taking into account the chemical and geotechnical properties of the material received from the donor site, a treatment strategy was developed and implemented.
6,000 tonnes of materials received from the Maliphant Sidings Site were treated and tested by engineers from Ramboll Environ to confirm compliance with the designated specification and suitability for the use intended.
Reuse of Treated Material (Recycling)
Ramboll Environ produced a Material Management Plan [MMP] documenting the whole recycling / reuse process (i.e. donor – treatment – reuse). The MMP was signed off by a Qualified Person in accordance with the requirements of the CL:AIRE Code of Practice prior to the infilling works commencing.
The treated material was then reused by the appointed contractor for the infilling of the hot mill pit.
The Treatment Hub enabled the recycling / reuse of material accepted from the Donor Site. The treatment / recycling process was fully compliant with the ‘End of Waste’ requirements enabling reuse of the material as a product in accordance with the designated specification as stipulated by Ramboll Environ.
The recycled materials were provided at a very attractive commercial rate.
The sustainable reuse of significant volumes / tonnages of soils resulted in Volker Fitzpatrick Rail being awarded the CIWM 2014 Award for Sustainable Construction and Demolition. The CIWM Award Press Release is shown in Figure 4 below.