In 1992, the Avenue Coking Works near Chesterfield in Derbyshire closed its doors. This ended nearly forty years of production, leaving the site a mess of leaky tanks, pipelines, waste tips, lagoons filled with tar and soil poisoned with cyanide and arsenic.
Homes England took ownership of the site in 1999 with the remit to develop a strategy which would transform what was once regarded as one of Europe’s most polluted sites, into a useable space fit for housing, businesses’, public spaces, and nature reserves.
What we did
We played a key role in one of the most ambitious and effective remediation projects ever undertaken in the UK. We worked with soil and waste treatment specialists, Sita Remediation and DEC, as the VSD Avenue Joint Venture.
We made the site safe from pollution and created an environment where wildlife thrives, by remediating 180,000m3 of badly contaminated material. We then moved 2,200,000m3 of earth to sculpture the site for its end use and built access roads and bridges to traverse the site and its waterways.
We used UK-first technology to clean the most heavily polluted material. We designed, constructed and commissioned a £6.5m thermal desorption unit, using technology proven in The Netherlands. We fed 180,000m3 of material - contaminated with benzene, phenol, cyanide, solid tar residue and arsenic - into the unit and a series of kilns and chambers were heated up to 1000oC, which vaporised and ‘cracked’ the contaminants into their constituent parts. These were then treated by filtration and acid scrubbers before being safely released.
We saved time and lowered energy use by doubling the unit’s productivity. We trialled and implemented many innovative ideas, such as pre-treating material and optimising the amount of granular material added to contaminants.
We also treated contaminated water. Over 200 Olympic swimming pools worth of water passed through our treatment plant, where chemical dosing corrected pH levels before it was released into sewers, or reused in the thermal desorption unit.
We made the site safe from flooding, by building a large culvert, realigning 600m of the river, strengthening the banks, and installing new drainage and sewers. The scheme protects down-river Chesterfield from flash floods. If needed, the nature reserve that now forms part of the northern end of the site can temporarily flood and hold back flood waters. Our designers won an ACE award for the temporary cut-off wall cofferdam, that allowed us to safely excavate contaminated materials from this part of the site.
We transformed one of Europe’s most polluted sites and an area the size of 140 football pitches, is now home to a nature reserve, sports pitches, green open spaces, 500 new houses and business units.
Wildlife is thriving and we translocated 8,000 newts and water voles before construction started. We built badger setts, snake habitats and a kingfisher nesting zone. The final design of the project included the provision of a newt reserve as well as a vole retreat.
We won two Considerate Constructors Scheme Gold awards for our approach to community and stakeholder engagement. We recognised we were developing a community asset and engaged local people from the planning stage, right through to the construction phase. Residents helped us monitor odour and we opened a widely used on-site visitor centre that doubled up as an education centre for local students.
The client and local community were delighted with the site’s transformation and quality was recognised by the respected industry bodies. In addition to the two Considerate Constructors Scheme Gold awards, our remediation approach won the ‘Judges' Special Award’, at the 2018 Brownfield Briefing Awards.
We also won the CEEQUAL ‘Excellent’ Whole Project Award. CEEQUAL is the world’s leading sustainability rating scheme for infrastructure, engineering and public realm projects. The site was praised for its extensive ecological design and management, sustainability of the remediation works and effective stakeholder consultation. The CEEQUAL judges said: “This was a ground-breaking project, the scale of remediation required is probably beyond anything ever seen before.”