Pressures on soil in the built environment
An overview of construction industry practices that have the potential to damage or restrict soil function.
Soils provide various important functions and services for society, including water infiltration, flood mitigation and the protection of valuable biodiversity. They need to be protected and managed to optimise these functions. Construction and development activities can damage the soil, preventing it from carrying out these natural functions.
Renewing soil
If soil is permanently removed and not reused, this could result in the loss of an irreplaceable natural resource. Topsoil is particularly valuable because of its fertility. You should find a sustainable use for any waste topsoil rather than send it to landfill - see uses for surplus topsoil.
Stockpiling soil
When soil is stockpiled there is a risk of it being mixed with subsoil components and other construction materials, which reduces its quality. There's also a risk of the stockpiled soil becoming compacted and eroded by the weather. If you keep too large a stockpile of topsoil, it can result in a loss of quality through lack of oxygen. For more information on soil stockpiling techniques, see how to manage soil during construction.
Compacting soil
Compaction is a common problem during construction projects. Poor soil handling techniques, inappropriate on-site storage of materials and trafficking - particularly by heavy machinery - can all contribute. Lack of oxygen and poor drainage in compacted soil restrict its ability to support vegetation.
Sealing soil
If soil is sealed - ie covered with an impermeable material - it's prevented from functioning properly. As well as removing an area that could support vegetation, this also damages a natural drainage characteristics. As sealing will occur as a result of development, you and your client should consider how to minimise the footprint of any building and try to reduce the loss of soil function. For information on protecting soil function and sustainable drainage systems, see consider soil protection before construction begins.
Contaminated soil
There are many types of soil pollution and contamination - including chemical spills and building rubble. These can all contribute to a loss of soil function.
Importing soil
Importing soil is common practice for landscaping projects. Unfortunately, this is often accompanied by a poor understanding of soil management. This can result in unsuitable soil materials being imported or some of the problems described above, such as compaction or contamination - see sourcing, importing and manufacturing topsoil.
You can also download a code of practice for soil use on construction sites (PDF, 737K).