8 minute read
Policy outlook: Soils and the built environment
Retaining healthy soils in open areas post-construction is important for supporting biodiversity and healthy greenspaces and reducing flood risk. © Birgit Höntzsch
The co-leaders of the Soils in Planning and Construction Task Force set out the current policy and regulatory landscape of soil in the built environment, highlighting the action required for greater soil sustainability.
Soils, generally, have long lacked strong governance, despite the consequences of soil degradation being well understood. For example, 90 years ago, the Dust Bowl drought in the US saw over a billion tonnes of soil blow off the Great Plains, devastating both local communities and the economy. This disaster prompted the creation of the world’s first soils policy, the Soil Conservation Act, under President Franklin Roosevelt, who famously warned, “The nation that destroys its soil destroys itself”.
Yet in the decades that followed, soils remained, in many countries, unprotected and ungoverned, with little more than voluntary guidance or advice on sustainable soil management. This has contributed to the alarming state of soils today, where 40% of the world’s soils are classed as degraded by the UN, with estimates reaching as high as 60–70% for Europe.
The past 10 years, however, have seen a major surge in international soil policy interest and innovation. The 2015 adoption of the IPCC (Intergovernmental Panel on Climate Change) Paris Agreement highlighted the role of agricultural soils in mitigating climate change, elevating soils on the global policy agenda. The UN’s International Year of the Soil, also launched in 2015, further emphasised the critical multifunctional role of soils. Since then, the EU has introduced a Soil Strategy for 2030 and established its first Soil Monitoring Law. Similarly, soil-related policies have become more prominent across the four nations of the UK, for example through Northern Ireland’s Soil Health Nutrient Scheme, the Sustainable Farming Incentive in England, and the Sustainable Farming Scheme in Scotland.
However, policy has largely focused on soils in agricultural and natural environments and the regulation and consideration of soils in the built environment lags significantly behind. In the UK, policies and guidance on soils in planning and construction are highly fragmented, narrow in scope, and predominantly voluntary. For example, the National Planning Policy Framework only awards value to soils with a statutory status (e.g. peatlands) or those identified as of good quality, as described by the Agricultural Land Classification (ALC). The ALC alone, however, is insufficient for assessing the full role of soils in sustainable development, as acknowledged by Natural England. It focuses on only one ecosystem service – food production – and ignores the significance of soils in other ecosystem services such as water storage and flow regulation, carbon storage and climate regulation, or in supporting biodiversity, given it is home to more than half the species on earth, In England, Defra’s Code of Practice for Sustainable Use of Soils on Construction Sites offers valuable guidance on soil functions and best practice but remains a voluntary measure with limited adherence in practice. An updated version of this code is expected soon.
Currently, most of the rules, regulations, and advice on soils in construction centres upon handling soil as a waste product. Soils that need to be removed from construction sites are automatically classified as waste and must be disposed of at licensed facilities as inert, hazardous, or non-hazardous material. In England and Wales, if there is certainty of use, soils can be reused on-site without waste controls applying under the Definition of Waste Code of Practice (DoWCoP). This is a voluntary industry code of practice from CL:AIRE (a UK charity committed to providing a valuable service for all those involved in sustainable land reuse). However, if storage duration exceeds 12 months or the DoWCoP conditions are unmet, a recovery permit from the Environment Agency is required. For reuse of soils on other sites, specific environmental permits or exemptions under the DoWCoP must be obtained.
While there are some potential pathways for soil use or reuse in construction, the volume of soil sent to landfill in the UK remains alarmingly high. An analysis of England’s waste data for 2023 highlights that 55 megatonnes (Mt) of soil waste were received by permitted facilities in England that year. Only 1.5% of this was classed as hazardous waste. Over half of the soil waste classified as inert (more than 25Mt) was sent to landfill.
To put these numbers into perspective, the mass of soil sent to landfill from development and construction sites is approximately eight times greater than the annual soil loss from erosion on agricultural land across all of England and Wales. This is especially striking given that agricultural land covers a vastly larger area than land under construction. These figures underscore the urgent need for more sustainable and efficient soil management practices within the construction sector.
Why does so much soil end up in landfill? While there are some pathways to reuse, there is a complex set of factors driving this trend. Poor early planning, lack of space on-site, and inadequate on-site monitoring can lead to soils being classed as waste. Waste storage exemptions available through the Environment Agency can also restrict the volume and timeframe for soil storage. Current attitudes towards soils also contribute: soil reuse is often seen as time-consuming and costly (even though reuse could reduce costs in machine time, fuel and topsoil imports), with landfill disposal considered a cheaper and more convenient option. Waste misclassification and crime further exacerbate the issue as soil is frequently mislabelled or mixed with demolition waste to evade higher taxes, reducing its potential for reuse.
Additionally, economic fluctuations and large-scale infrastructure projects create uncertainty in soil supply and demand, making reuse planning difficult under the current system. Addressing these barriers requires regulatory reform, better planning, and stronger financial incentives for sustainable soil management.
The problem of this ‘waste’ has been acknowledged by policymakers. In the 2023 Environmental Improvement Plan, the government committed to developing a pilot Soil Reuse and Storage Depot Scheme by 2026 to help reduce soil waste by encouraging reuse and remediation. Recommendations for this scheme have recently been made, including the development of soil hotels (fixed facilities for the temporary storage of clean soils for reuse) and soil hospitals (where contaminated soils are remediated or improved to allow reuse).
While these commitments and proposed new schemes to reduce soil waste and enable reuse are encouraging, the significance of soils to sustainable urban development goes far beyond the management of waste. Soils are the foundation of sustainable development, and if considered and treated well throughout planning and construction, they could contribute positively to carbon sequestration and climate commitments, supporting biodiversity above and below ground, and mitigating the risks of floods and heat waves.
The cross-sector Soils in Planning and Construction Task Force is active in promoting a fuller appreciation of the multifunctional value of soils and supporting the adoption of soil sustainability in practice. The Task Force’s work, which can be found on our website, has highlighted that local planning policy is a key leverage point. Through this, requirements and mechanisms that deliver soil sustainability throughout the development timeline – from preplanning to post-development – can be embedded. A recent project, Local Soils, has been funded by the Engineering and Physical Sciences Research Council and Arts and
Humanities Research Council, with support from Lancaster City and Cornwall Councils. It has focused on the development of ‘model policies’ for local authorities on soil sustainability (see case study, p32). Over 40 representatives across UK policy and industry have been engaged in the development of this guidance through focus groups and in-person co-design workshops, the results of which will be shared soon through the Soils Task Force.
Ultimately, there is some distance to go to achieve soil sustainability in construction, both in the UK and globally. Strong policy is important, but pragmatic changes in practice will require not only policy innovation, but also cross-sector collaboration and buy- in. The future of our soils, and our built environment, depends on the decisions of many throughout the development process. Working together is the only way to ensure this vital resource is not treated as dirt. If you are interested in working with us or in the Task Force, please get in touch. at soilstaskforce.com
Jessica Davies is Professor of Sustainability and John Quinton is Professor of Soil Science at Lancaster University. Together they lead the Soils in Planning and Construction Task Force.
