Value: £7.0 million
The reclamation of the 15ha Woolwich Arsenal site involved the treatment of 240,000m³ of contaminated material by a soil washing plant designed and built in-house by VHE’s site team.
The customer opted for soil washing due to the physical nature of the affected material and the planning requirement to keep lorry movements to a minimum. Following screen testing for explosive residues and the separation of materials of different sizes, soil was washed, crushed and screened to allow as much as possible to be re-used in the subsequent re-engineered ground works operation.
Phase 1 involved the treatment by soil washing of 130,000 m³ of material. Phase 2 extended the washing to a further 45,000m³ (amounting to an additional 75,000 tonnes). During Phase 1, daily outputs of 1,000 tonnes were not uncommon and between 250 and 500 tonnes were normal. Between 80 and 85% of the input material was re-used, of which 70% was gravel and 30% was sand.