WRAP has published new guidance outlining good practice for the use of quality compost across a host of building, civil engineering, landscape and regeneration projects.
Good Practice Guide for the use of BSI PAS 100 Compost
The Good Practice Guide highlights the practical, environmental and cost benefits of using compost in landscaping applications and offers straightforward, hands-on guidance.
Compost can be used as a stand-alone product or blended to create bespoke soils for a specific purpose. It is effective in lowering bulk density, improving soil structure and water retention; enhancing germination; and providing slow-release nutrients such as nitrogen, phosphate and potassium. In addition, the incorporation of compost provides valuable opportunities for carbon sequestration and, in many cases, offers significant cost savings by reducing the need for fertilisers and expensive topsoil.
Landscape practitioners are successfully using quality compost for the regeneration of brownfield sites and maintenance of existing outdoor areas. Work is also taking place with engineers to control erosion, reduce the severity of flooding, and to build sustainable urban drainage systems such as green roofs.
Areas of guidance
The Good Practice Guide can be applied to small, medium and large-scale projects. It offers specific guidance on: Soil manufacture and habitat creation; Housing and mixed use development; Energy crops on brownfield land; Sustainable urban drainage systems (SUDS) and green roofs; Slope stabilisation and erosion control; Recreation and sports turf; Landscape maintenance; and Bioremediation.
Each area is discussed in detail with a range of supporting case studies and reports to illustrate the benefits and considerations required. For example, the associated cost savings generated by using PAS 100 compost are highlighted under Soil Manufacture and Habitat Creation, while the benefits reported by those incorporating compost in the design of SUDS or green roofs include a reduction in rainfall run-off, and assistance in delivering local, regional and national biodiversity action plant targets.
The Site Investigation, Sampling and Guidance sections provide practical advice on how and when compost use is applicable – for instance, those planning football pitches or golf courses need to know that high rates of compost application sometimes reduce traction, particularly in wet conditions. Similarly, anyone manufacturing bespoke soils for biomass projects or wildflower meadows will be keen to learn that the rich nature of compost can sometimes result in excessive weed growth.
Taking this a step further, the Application guidance provides indicative blending ratios to create the right level of nutrients or, in the case of Slope Stabilisation, using engineering solutions such as compost socks or vegetated gabions to aid application and longevity.
For those starting out on a project, the Decision Tool flow chart asks a series of questions that signpost the audience towards the most appropriate actions. This links to four technical documents which offer further information on compost in soil improvement, topsoil manufacturing; soil amendment and surface treatment; and compost in erosion control, sustainable urban drainage systems (SUDS) and green roofs.
WRAP's Compost Good Practice Guide is based on evidence gathered over the last four years.
Katherine Church, Project Manager Landscape and Regeneration at WRAP, said: “BSI PAS 100 compost is widely available throughout the UK. Armed with this new guidance and access to local producers, we are confident that more businesses will realise the advantages of using PAS 100 compost, whatever their area of expertise.”