Scottish quarry lead the way in land restoration

WRAP (Waste and 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.

Due to the geology of the quarry - which supplies raw materials exclusively for the cement manufacturing process - a significant quantity of material has to be moved to access its limestone reserves.

Over three million tonnes of material is excavated each year using an opencast strip mining technique.

Although progressive restoration follows this strip mining, the natural topsoils are sandy, stony and nutrient poor, rendering restoration to a good agricultural standard difficult.

The conditions at Dunbar 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 enable better growth of sustainable native woodlands and grasslands and provide greater water retention and erosion prevention capacity.

Dunbar Works' quarry manager, Mark Scrutton, explains: "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 minimising water logging, which are all essential factors for land restoration".

""This project builds on our track record of sustainability at the works.

This has become established through using alternative materials such as used tyres as part of the cement-making process.

Using this compost is another example of our commitment to recycling waste materials in delivering tangible benefits, such as reducing nutrient leaching and improving soil structure and water retention".

""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) are providing scientific advice for the site.

The project, which started in November 2006, is due for completion in November 2007, 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 per cent," says 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".

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 consistent high quality level and is also safe, reliable and sustainable.

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