THE CHALLENGE:
Following demolition of the former Crown Closures factory, extensive remediation and enabling of this 2.75Ha site was required for a proposed new residential development with private gardens. Previous site investigations had discovered various contaminants on-site including asbestos containing materials (ACM’s), mercury, hydrocarbons and solvents, plus a network of ducts, buried tanks and other infrastructure. The site was located in close proximity to residential housing on all sides, presenting a significant challenge to manage fugitive emissions during all works.
OUR SOLUTION:
Soilfix designed and delivered a Materials Management Plan in accordance with CL:AIRE DoWCoP to maximise re-use of site materials, resulting in a sustainable and cost effective solution, which included;
- Breakout and processing of 13,000m³ slabs, concrete aprons and heavily reinforced buried obstructions, including the reinforced concrete base of the factory chimney base which extended ~4m below ground level;
- Decontamination and removal of various duct systems and buried tanks;
- Targeted excavation and segregation of mercury contaminated soils – field screening using a vapour probe for waste minimisation;
- Processing of 20,000m³ Made Ground to remove oversize and deleterious materials;
- Ex-situ bioremediation of 500m³ of hydrocarbon and solvent impacted soils;
- Off-site disposal of hazardous wastes (segregated asbestos containing materials and mercury contaminated soils) in accordance with Duty of Care;
- De-risking Made Ground to allow future groundworkers to work unhindered;
- Use of a GPS-controlled Dozer for efficient regrade of the site soils to fit proposed levels at underside of construction & capping;
- Installation of development platforms for piling – sustainable ‘hybrid’ platforms comprising cement stabilised soil / crushed aggregate running layers used to minimise the sites surplus soil volume;
- Segregation of >3000m³ clean natural soils generated during the site-wide turnover, stockpiled for future re-use as subsoil capping in the gardens during the construction phase, delivering significant savings and environmental benefits compared to the alternative of import; and,
- Third party verification by consultants RSK including full regulatory signoff.
As an additional benefit to the client, Soilfix were able to handover significant areas of the site early, allowing groundworks and construction to commence ahead of programme.
