Seeking a sustainable remediation method that was economically feasible was central to Grontmij’s strategy for cleaning up a former gasworks site in Lossie Green, Elgin, owned by Moray Council. This project involved I & H Brown as principal contractor, and the use of specialist soil washing plant operated by DEC. The project saw more than 80 per cent of the excavated soil re-used, thanks to this sustainable remediation approach being pioneered by Grontmij in the UK.

Judges for the Brownfield Briefing Remediation Innovation Award considered several categories in awarding Grontmij. These included the appropriate use of sustainability analysis, how the environmental aspects of the project were managed, whether it was designed to optimise long-term environmental benefits, how energy consumption was kept to a minimum and what renewable sources were used.

Soil washing is a sustainable, cost effective and viable alternative to landfill disposal. It works by separating and cleaning contaminated soils, removing a variety of organic and inorganic contaminants, such as hydrocarbons and metals.

Frank Price, director of Environment at Grontmij, said: “We’re delighted to have been recognised for our work with The Moray Council in Elgin. Soil washing considerably reduces the volume of contaminated earth requiring disposal, demonstrating a highly sustainable and commercially beneficial alternative to traditional excavation and disposal practices.”

“At Elgin we were able to reuse more than 2,770m3 of material, which would otherwise have been treated as waste, requiring haulage off-site to landfill and the equivalent amount of clean quarried stone imported.”

Using the soil washing technique and recycling the material has also minimised the number of truck movements and associated emissions, noise, congestion and health and safety issues, which would have been anticipated for a remediation project of this size.

Mr Price said: “The nearest landfill capable of accepting waste of this nature was over 300 miles away in Teeside. We estimate that by reusing the soil on the site we’ve avoided more than 275 return lorry trips, saving in the region of 70,000 vehicle miles.”

Just 65 return lorry trips were necessary to dispose of the filter cake, containing the removed coal tar and spent oxide contaminants, and small quantity of material, which could not be treated.

Helen Barron, head of Contaminated Land at Moray Council, said: “This project highlights the extent to which sustainable remediation has developed in recent years and innovative techniques supporting this are readily available today.”

“We’re committed to working in harmony with the environment and Grontmij’s considered proposal put this at the heart of the project. We’re delighted with the results and thrilled the project has received this award.”

The project was designed to clean-up the site and prevent pollution of the underlying groundwater and nearby surface waters. The land has been brought back to use as a public car park and landscaped ground for recreational use.