Maximizing beneficial reuse through the use of a novel dredging contract
Type:
Presented during:
CEDA Dredging Days 2007 - The Day After we Stop Dredging, Rotterdam
Authors:
Clay N, Port of London Authority; Bray N, Dredging Research and Hesk P, Van Oord United Kingdom, United Kingdom
Abstract: The Port of London Authority (PLA) has a statutory responsibility for maintaining safe navigation within its port limits, which include the dynamic sandbanks of the Thames Estuary. The potential long-term instability of one of the southern access routes into the port led PLA to consider the provision of improved access by the navigational dredging of Princes Channel. In accordance with Government guidance and International requirements, the PLA is committed to using dredged material in a beneficial manner wherever possible. By working in partnership with the dredging industry, the PLA sought sustainable options for using the dredgings, such as infrastructure development, habitat creation, coastal defences and recycling within the estuary system. To facilitate this approach, the PLA employed Dredging Research Ltd to develop a Contract incentivising dredging contractors to explore and acquire opportunities for the beneficial reuse of this material, but without commitment if no such needs existed.
The Rochester Riverside Development, part of the Government promoted and funded Thames Gateway Regeneration, is improving a brownfield site to a standard where commercial, residential and leisure development can be instigated. A key element of these enabling works was the improvement of the site's flood defences, this being partly achieved through land-raising. Van Oord UK Ltd was awarded the Contract for supplying 340,000m3 of sand fill, using material from Princes Channel in accordance with the PLA's Pro-Forma Contract. The seemingly ideal use of this material was not straightforward; the designation of dredgings as waste resulted in protracted discussions between the PLA / Van Oord partnership and the regulatory authorities before the works could commence. The successful completion, in August 2006, demonstrates that estuary dredgings can legitimately be used within the construction sector; providing cost savings and environmental benefits when compared to the use of virgin aggregates.
Keywords: Sustainability, Waste, Partnering, Land Raising