Project: Chadwell Heath Hospital, Chadwell Heath
Client: Major Developer
Contract Value: £ 670,000

Knight Environmental Limited provided a complete programme of consultancy and remediation support including demolition, site investigation, risk assessment, remediation design and liaison with the Regulatory Authorities for the development of the former Chadwell Heath Hospital.

Parts of the site were found to have elevated levels of metals and polyaromatic hydrocarbons in the soils. The majority of these occurrences were in the Made Ground deposits with a small number located at shallow depths within the natural subsoil or topsoil.

The key operations during the remediation works, were:-

Site clearance, with stockpiling and disposal of general waste.
Removal of asbestos and biological waste from buildings.
Dismantling and demolition of existing buildings.
Lifting of ground slabs and hardstanding.
Excavation and removal of below-ground structures and
   processing of these materials for re-use on site or removal off
   site.
Reclamation of salvageable materials for recycling.
Excavation and removal of contaminated Made Ground (hotspots)
   to area-specific depths followed by validation sampling.
Backfilling with clean site-won material to final remediation levels.
Monitoring groundwater quality and soil-gas concentrations.

Soil disposal was undertaken in accordance with Section 34 of the Environmental Protection Act (1990) and with due regard to the 'duty of care' provisions. Wastes were transferred using Knight Environmental consignment notes for hazardous non-special waste. Special waste was consigned using Environment Agency Special Waste notes in accordance with Special Waste Regulations 1996.

A total of approximately 4,600 square metres of contaminated ground was excavated to a depth of between 0.3 and 0.5 metres below ground level with disposal to a licensed wastes management facility.

Knight Environmental Limited supervised and managed all of the site works and provided a completion report to the Regulatory Authorities for approval on completion of the site works. The works were fully validated and the site was deemed suitable for its proposed end-use.