As Principal Contractor John F Hunt was contracted to demolish and remediate a former paper mill that straddled a major river (River Culm) in Devon. The mill had a heavy industrial usage dating back to the 1800’s and left a significant pollution legacy in the form of heavy and light hydrocarbons and asbestos in the soils.
The initial design problem, was how to remediate the contaminated ground either side and beneath an existing culvert, which had a substantially active water flow and a very rapid flood response during heavy rainfall.
Remediation works would need the ground either side of the culvert to be excavated and treated whilst the river was flowing and there was a serious risk of contamination to the river.
The John F Hunt team designed, agreed and constructed a river diversion (pictured right) so that the flow through the culvert could be stopped, allowing remediation of the ground around it and the eventual restoration of a naturalised river channel.
The excavated and treated materials were subjected to a strict stockpile and materials management process. This allowed testing, categorisation and segregation to be undertaken without mixing wastes and materials, therefore enabling suitability for re-use. The work was carried out under a CL:AIRE code of practice Materials Management Plan.