Keltbray has developed a remediation technique at Worthy Down near Winchester.
The firm has been working there since 2015 as part of its biggest contract for Skanska at the £280M Wellesley development, which will provide a new training college for the Ministry of Defence.
The remediation technique reduces the need to export and import large volumes of material for this contract. This involves materials management of over 60,000m³ of the excavated construction waste (enough to fill 500 double decker buses), which is being reused in non-construction areas on site.
By reusing the material, the impacted material remains on site, and will be used to help shape parts of the new development. Once the construction arisings have been engineered in place beneath the sports pitches, it is covered with clean chalk that will form the base for new sports playing fields.
Kelbray Remediation engineering manager Mark Pescodd said: “We are using careful segregation plans for the material types on site so that potential contaminants can be managed effectively. The material is then stockpiled. However, we will have to rotate these seven to eight metre tall stockpiles which include up to 50,000m³ of material from one end of the site to another so that the site can remain operational at all times.
“After we stumbled upon Roman remains on site in 2015, 11 Roman burials, artefacts and fossils have since been found, so we have continued to tread carefully and work closely with archaeologists and technical geologists to phase the work on ground that has not been broken for centuries.”
Keltbray Remediation has drawn on expertise from across the Kelbray, and work will now commence on the second tranche of the three works phases; involving around 100 people working in five site teams until 2020.