Designing Out Waste
Network Rail are in the midst of delivering the biggest investment in the railway since the Victorian era. All our work from designing and building iconic new stations, signalling upgrades, electrification, track renewals and bridges produces waste and the waste we produce has a significant impact on both our environment, costs to our business and thus value for the tax payer.
A construction and demolition project of this size and scale inevitably presents a range of challenges and opportunities with regards to waste and material management. As part of our sustainability vision Thameslink Programme committed to “reduce waste generated and disposed of on TLP” through “reducing waste during the design process” and “diverting at least 90% of our waste from landfill using the waste hierarchy”.
To this end, at design state a series of Designing Out Waste workshops were held using the WRAP (Waste and Resources Action Programme) Designing out Waste toolkit. The objective of these workshops was to collaboratively challenge the design and construction process to identify where we could reduce waste in design and construction through:
Offsite construction – use of prefabrication
Modular and pre-fabricated components were used for bridge decks, platforms units, lifts, escalators and station furniture and standardised components for station glazing. Modular and pre-fabrication reduces material use and waste, reduces risk of pollution, minimises impacts on our neighbours through quieter construction and less road congestion from deliveries. It also provided a number of economic benefits such as improved product quality, reduced installation programme, reduced materials double handling and improved site logistics.
Reuse and recovery of materials – Re-use of demolition materials
For example, crushing waste arising throughout the demolition works for re-use within the station.
Recycling hazardous waste
At London Bridge aerosols were recycled through a specialist Aerosol Piercing Unit enabling aerosol cans to be recycled like any other metal thus diverting waste from landfill.
At London Bridge plasterboard was used to fit out the station accommodation, which is a difficult material to dispose of as all gypsum based wastes must be disposed of to landfill thus increasing our impacts and costs. By working with our suppliers we were able to return our plasterboard waste products for recycling and reuse into a variety of products that are sold again to construction projects.
Waste segregation is part of standard activities, however as our worksite reduced and space became constrained, we maximised off-site segregation and recycling. Dedicated off-site storage areas were used for storage of construction materials supported by just in time deliveries to reduce volume of material held on site. This was supported by returning surplus materials to the storage area for reuse during construction.
200,000 tonnes of excavated soils at London Bridge were tested and segregated on site into inert, hazardous, non-hazardous and special non-hazardous waste to prevent mixing of waste and costly waste disposal to landfill. All soils were treated at a soil treatment facility according to their type, for example through soil stabilisation or bioremediation. Treated soils were then transported along the River Thames by barge and incorporated into other land reclamation projects. Each barge carrying 1000 tonnes removed 50 lorries from congested London roads and reduced carbon emissions by 60%.
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