The Waste and Resources Action Programme (WRAP) Scotland is at the forefront of turning contaminated, industrialised groundscapes into usable green and urban spaces.

SCOTLAND boasts four of the UK’s ten largest regeneration projects outside London, worth more than £9 billion. Yet while the future of these places - whether housing, retail, transport, agriculture, sport or green space - is often caught in the headlines, the real secret of their successful regeneration is sometimes overlooked.

An important part of a successful development that attracts people, businesses and jobs is the landscaping element. It helps provide space for leisure activities contributing to the development. To do this, a topsoil is required which has the capacity to sustain plant growth in all weathers and help sustain leisure pursuits be they football pitches, golf courses or open space.

Regenerating sub standard soils is a common challenge in Scotland where there are large areas of brownfield land left vacant, derelict or contaminated by past industrial use. These activities often leave a soil or other raw materials that are not capable of supporting plants. Plus the quality of Scottish soil is very much in the spotlight at the moment as a consultation is launched for the first ever framework to protect Scotland’s soils from pollution and climate change.

WRAP Scotland is one of a number of specialist organisations that has contributed to thinking around the soil framework. In doing this, WRAP has drawn on experience from a number of brownfield regeneration projects across the Scottish Central Belt - as well as other locations in the UK. Specifically, WRAP’s ‘trailblazer’ projects have been designed to demonstrate the use of BSI PAS 100 quality compost made from municipal garden waste in soil manufacture and restoration.

This work has shown how quality compost can be mixed with existing mineral material on site - such as screened colliery shale or low quality excavated subsoils - to manufacture new topsoils capable of supporting plant growth.

One of these trailblazers has taken place at the Heartlands Polkemmet reclamation scheme which is the largest of its kind in Scotland. Years of deep and open cast mining operations at the site left it with more than four million cubic metres of colliery waste, devoid of any soil and in desperate need of restoration. The aim of the project was to transform part of the 470 ha former open cast coal mine into two championship golf courses, leisure facilities and residential housing - giving the whole area a new lease of life.

In particular, the site owners Ecosse Regeneration wanted to remediate the land in a sustainable and cost effective way, avoiding the traditional method of exporting contaminated materials and subsoils from the site and importing new topsoil. Trials were undertaken to research the benefits of mixing colliery waste and compost to develop optimum growing conditions.

Despite late sowing and a heavy frost, the field trials produced strong and diseasefree grass growth.

Project manager at Ecosse Regeneration, Alex Muirhead, explained: “Quality compost offers an excellent balance of water and nutrient retention properties when mixed with screened colliery shale and we were pleased with the results from the trial, which showed rapid and uniform establishment of turf grasses without weed problems.

“The trials also produced cost benefits - approximately £10 per tonne saving when comparing the cost of manufacturing the blended compost and colliery waste to importing topsoil.”

The compost for the project was sourced from Scottish Water, GP Green Ltd, Fourth Resource Management Ltd, West Lothian Recycling and William Tracy Ltd.

Another high profile trial has taken place at the former Ravenscraig Steelworks in North Lanarkshire which operated from 1957 until 1992 when it was closed down and demolished. The 450 ha site is the equivalent area of 700 football pitches and lay disused until work began on the new town of Ravenscraig in 2007, which will see 3,500 new homes being built. Development is now underway on 162 ha of the site, with the remainder earmarked as open community parkland areas for residents and wildlife.

The development is being undertaken by Ravenscraig Ltd, a partnership between Wilson Bowden Developments Ltd, Scottish Enterprise and Corus Plc, with Turner & Townsend providing project and cost management for the current Phase One of the development.

Due to the site’s former use as a steelworks, there was insufficient topsoil available to create and landscape the wildlife corridors and extensive woodland. However, the site did contain a number of potential soil forming materials including steel furnace slag and glacial drift material which could be combined with quality BSI PAS 100 compost to produce a soil capable of sustaining plant growth.

WRAP has worked with Ravenscraig Ltd to identify suitable areas for the use of quality compost on the site. To date, approximately 3,600 tonnes of BSI PAS 100 compost, sourced from Scottish Water, has been used to create different soils and four trial areas have been set up to gauge the optimum ratio mix of materials in which to grow woodland.

A spokesperson for Scott Wilson - the company that led on the initial design phase work for the landscaping on the project - explains: “The site was covered in two different types of slag (blast and steel furnace), and disposing of it would have been expensive and not ecologically sound. Through blending the steel furnace slag with clay subsoil and BSI PAS 100 compost we have produced a moderately alkaline soil that can be used as an effective growing medium.”

Pilot projects are also being undertaken with support from WRAP at the following locations:

Scottish Resources Group

Damside - North Lanarkshire, Dalquhandy - South Lanarkshire, St Ninians - Fife

These three surface mining sites are using quality compost to restore land to rough grazing and woodland, as well as supporting the growth of biomass crops such as short rotation coppice willow

Stirling Council

Raploch URC - Renaissance of Raploch

This area has undergone prior demolition works, leaving a thin layer of poor reclaimed soils. 250 tonnes of quality compost is being used to help restore the soil for domestic gardens and communal back-courts.

Lafarge Cement - Dunbar

Works in East Lothian, Scotland

This former quarrying area issuing 2,300 tonnes of quality compost to restore and improve the soil for the growth of woodland and grazing areas.

Iain Gulland, Director for WRAP Scotland, said: “Previous trials have shown that using locally sourced quality compost to make soil, not only saves on transportation and landfill costs; it also produces a high quality, fertile substrate for sustainable landscaping.

“It is also hoped that using compost enriched soils could bring real benefits to the UK house building industry. Traditionally, on site mineral resources (such as trench arisings and subsoils) are often not considered as appropriate input materials. Using compost, they could be used to manufacture soil bringing cost savings and reducing pressure on limited reserves of natural topsoils.”