The former industrial site was remediated so that it could be further developed for mixed commercial and residential development. Cannon Wharf had a long history of industrial development since 1834, leaving the site contaminated with heavy tar hotspots and PAHs from gas works waste with a potential impact on groundwater on and off the site. Made ground was also contaminated with heavy metals and asbestos, some fragments of asbestos embedded within the concrete slab and foundations. A number of underground storage tanks (USTs) were also present.
Cognition was contracted by Barratt London to remediate the site and treat contaminated groundwater in order to make the site suitable for planned construction works, high-rise residential blocks with some areas of soft and hard landscaping. The key elements of these works included;
Remediation works were successful and all areas met the validation criteria and the site was deemed fit for re-use by the Regulators. Soils were reused on site to reinstate to pre-construction levels. Groundwater monitoring demonstrated the site no longer posed an environmental risk. Cognition also carried out the main drainage works which enabled the construction phase to be carried out with minimal need for excavation thereby minimizing disruption and disposal.