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 Treatment Hub was able to accept the material following a comprehensive review of the waste assessment commissioned by Volker Fitzpatrick Rail (carried out by ESG).
The hazardous / non-hazardous material (circa 16,000 tonnes) was shipped to The Treatment Hub with most of the remaining less contaminated soils being reused as engineering backfill on site. The bulk of the material (circa 14,000 tonnes) was shipped in an 8-week window between April and June 2014. A further 2,000 tonnes were shipped in December 2014.
The Receiver Site was a ‘greenfield’ site (not previously developed) and comprised of an area of rough ground. The site was selected by a local social housing association for the development of circa 30 new homes for the local community. It was proposed to construct a range of new two, three and four-bedroom properties on the site.
Reuse of Treated Material (Recycling)
The developer, mindful of costs on such schemes, contacted the Treatment Hub for suitable material meeting the required 6F2 specification for use as sub-base (on key elements of the development).
Earth Science Partnership [ESP] produced a Material Management Plan [MMP] for the site including the proposed reuse of the recycled material as sub-base. The MMP was signed off by a Qualified Person [QP] in accordance with the requirements of the CL:AIRE Code of Practice.
ESP recommended the use of recycled material as a substitute to imported virgin fill material. The material from the Treatment Hub was considered to be suitable both chemically and geotechnically.
The Treatment Hub was able to provide offer a sustainable and economic recycling solution. 6F2 material was transported to the site and utilised as sub-base resulting in a significant cost saving to the project (estimated at circa £10K). The developer was able to ‘call off’ material when required.
A treatment strategy was proposed and implemented to achieve the required totals and leachate values (based on the chemical criteria / specification for the required fill material at the Receiver Site). The material was required to meet the criteria for the 6F2 Highway Specification – it was therefore necessary to crush and grade the treated material appropriately. It was also necessary for some elements of the development to remove some of the fines content and accordingly the treated / crushed material was screened where required.
It was estimated that the Treatment Hub provided circa 2,000 tonnes of recycled material for use at the Receiver Site. It was necessary to demonstrate suitability for use and the specific requirement in terms of quantities.
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 ESP.
The recycled materials were provided at a very attractive commercial rate.
The Treatment Hub was therefore able to offer a sustainable and economic alternative to the use of virgin material.
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.