Scottish quarry aims to lead the way in land restoration

WRAP (Waste & Resources Action Programme) has announced the launch of its first trailblazer quarry site to use high-quality compost to restore brownfield land. Lafarge Cement’s Dunbar Works in East Lothian, Scotland, will use 2,300 tonnes of BSI PAS 100:2005 compost in a former quarrying area to restore and improve the soil for the growth of woodland and grazing areas.

The BSI PAS 100:2005 certification means that the compost, which is produced from source-segregated green waste such as grass cuttings, prunings and leaves, has been manufactured to a consistently high quality and is also safe, reliable and sustainable.

Owing to the geology of the quarry, a significant quantity of cover material has to be moved to access its limestone reserves. Over 3 million tonnes of material is excavated each year using opencast strip-mining techniques. Although progressive restoration follows this process, the natural topsoils are sandy, stony and nutrient-poor, rendering restoration to a good agricultural standard difficult.

These conditions made the quarry an ideal trial site to investigate the benefits of mixing high-quality compost with existing soil-forming materials to improve soil condition. The resulting properties of these improved soils should allow better growth of sustainable native woodlands and grasslands, and provide greater water-retention and erosion-prevention capacity.

Dunbar Works’ quarry manager, Mark Scrutton, explained: ‘We were interested in green waste compost for the project as it appears to be the best form of organic matter to manufacture soil with, both physically and nutrient-wise. A large proportion of the project will involve growing grassland and woodland in places where the improvement of soil may significantly enhance the final results. Compost helps the soil in a number of ways including boosting its organic matter content, reducing erosion and minimizing water-logging, which are all essential factors for land restoration.

‘We hope that the results of the trials will provide valuable information relevant to the whole quarrying and mining industry in the UK, setting a precedent for similar businesses looking to restore their land.’

The project is a Scottish collaboration, with the compost being sourced from Scottish Water Waste Services in Deerdykes, near Glasgow, and SAC (Scottish Agricultural College) providing scientific advice for the site. The project, which started in November 2006, is due for completion in November this year, with a full evaluation taking place over several years.

‘Previous trials conducted in conjunction with WRAP, which looked at the benefits of using PAS 100 compost in situ as a soil improver, have shown significant improvement in both cost efficiencies and the quality of the resulting topsoil. In some cases, costs have been reduced by over 50%,’ said Paul Mathers, key account manager for brownfield at WRAP.

‘This Scottish trailblazer project will determine the benefits of the use of compost in restoring quarried land, which will hopefully set an example for other firms in the quarrying industry to follow.’

For more information on how BSI PAS 100:2005 compost can help reduce the cost of brownfield regeneration projects, contact Paul Mathers at WRAP on tel: (01295) 817899.