Soil erosion and migration are not problems caused solely by adverse weather – they are often created and exacerbated by poor practice on-site.
Stripping a site of soil too early will remove environmental protection or compact the soil, ruining its quality, risking contaminated ground or causing erosion. These each negatively impact the physical, chemical and biological properties of soil, not least its ability to support drainage or vegetation. And these preventable problems will then be made worse by the weather – whether it’s rain causing soil erosion and migration, or dry weather creating dust.
Good practice on soil management and environmental protection is guided by a range of rules and regulations. The below actions are recognized as best practice in preventing contaminated ground, erosion or pollution when managing soil on a construction site or development:
Figure 1 – Soil stockpile on construction site
- Recognise that soils are a valuable resource – Topsoil is a valuable but finite resource. As a fertile material for supporting and growing vegetation, it must be carefully managed. Good practice sees it removed and protected before construction activities begin. While subsoil isn’t as fertile, it plays an important part in holding and draining water so it must be protected in its own way. If it is to be used for landscaping a development, where vegetation will be planted, it should not be stripped, but protected. If it cannot be kept clear of construction activities, it should be carefully removed, rather than risk degradation.
- Ensure stockpiles aren’t over 2m high – Where soil is being retained ready for future landscaping or to be sold, stockpile locations should be carefully chosen, situated on level, impermeable ground and never exceeding 2 metres in height. If a site doesn’t have room for stockpiling, it is worth weighing up the cost benefits of finding a suitable, sustainable off-site solution.
- Develop and maintain buffer grounds – Stockpiles should also be situated considering proximity to watercourses or drains and exposure to water runoff, to prevent silt from reaching rivers or streams. While water should be directed away from stockpiles, buffer grounds of vegetation close to watercourses will ensure any run-off from weather is captured.
- Apply binder to road surfaces – Where appropriate, a binder will capture and hold small soil particles to reduce dust creation on access routes and parking areas during dry weather. For short term use, simply spraying a road with water or reducing speed limits will also reduce dust.
- Divert water from roads – Managing run-off from roads onto nearby vegetation, ditches or basins will prevent water from flowing or pooling on the road and, where necessary, support plant growth. This can be supported with bunds, like small speed bumps, or by building ditches along the road edge.
- Manage road ditches – Ensuring these do not discharge directly to watercourses such as rivers, burns, lochs or wetlands is essential in preventing pollution. This is bound by legislation and heavy fines can be imposed for causing pollution.
By following these steps, environmental protection can be maintained. Stripping topsoils or subsoils too early or too much, compacting soils under heavy plant and machinery, or creating contaminated ground will not only reduce soil’s ability to capture and drain water and support vegetation growth, but also risk erosion, pollution and fines.
Environmental assessments and planning, and ongoing checks are essential. Remain mindful of the dangers or potential problems that can be caused by poor practice and consult guidelines or experts where required.