In this Sustainability Delivery Group Expert Talk, held in partnership with Jacobs, Yolande Macklin, associate director of land quality at Jacobs, David Griggs, senior advisor for sustainable places at the EA and Darren Beriro, principal geoscientist at the BGS, presented current research conducted for the EA on the development of a novel natural capital approach. This approach is used to evaluate the sustainability benefits from remediating and redeveloping contaminated brownfield sites.

Brownfield is key to sustainable place-making and regeneration across the country, but remediation is seen as a constraint rather than something that could be beneficial, according to Yolande Macklin Senior Associate Director at Jacobs, who has been working with the EA on the Remediation and Sustainable Growth Tool.

"What we wanted to do, as part of this project, was explore what was needed to mainstream an approach to valuing the benefits of remediation, to reframe it and to see it as a benefit rather than a constraint, or a liability in terms of cost as well."

Macklin explained the key research questions for the project: What is the vision of this tool to measure benefits of remediation and how do we affect change to achieve that? How might that be used to measure the benefits of post remediation? Is there really a difference and how we might present and monitor those potential benefits of remediation, so that they can be used in the overall decision-making process.?

David Griggs put the project in context: "Our purpose as an organisation is to create better places. We've got a wide range of roles and responsibilities to support the clean-up of contaminated land. We have advisory and regular regulatory duties in England. We have a rich industrial heritage that has left a legacy which can pose pollution risks to people, the environment and ecological systems, and it can be a blight on communities.

"But despite that, remediation can struggle to have its value communicated and as an agency we've struggled to maximise the opportunities and make the case for remediation and contaminated land management that goes beyond regulatory minimum, and to put remediation within environment net gain. What if we could better manage, measure and communicate the benefits? What would that mean for us?

"We thought that it would mean we'd be able to improve how we do things and how we advise others on how they do things. It would mean we would be able to secure more funding into remediation activity and into all operational roles in remediation, and fundamentally improve remediation outcomes. So, we've set out to explore the feasibility of a tool to better measure and communicate the social, economic and environmental value of remediation. But first, we needed to clarify our vision of what that really is and our understanding of how developing a tool would actually result in the change we want to see. 

Theory of Change

"So, to answer that question we looked at developing a Theory of Change as a method used across government, to understand and illustrate how a certain outcome can be achieved in a certain context."

The team mapped out a Theory of Change in this context over a series of workshops. The EA vision statement is to "deliver regional economic, environmental, and social net gain through the sustainable development of brownfield sites". The Theory of Change defines what changes need to occur to enable this vision, and outlines what inputs and activities are needed to effect tangible change through time. It was divided into five phases: Feasibility assessment [enabling activities and outputs]; decision support tool (outputs); deployment and real-world testing; good practice and policy formulation through changes in capacity and behaviour; and business as usual.

Griggs explains: "This first phase comprises a set of interventions that are essentially identified changes that need to trigger the change process - foundation elements that will help us move into phase two and beyond. They include activities like understanding the user needs for the tool and design options, fundamentally to characterise understanding what is already known about this research. We needed an evidence review."

The team evaluated links between remediation and sustainable development and how these are measured. More than 1400 publications were found, with 59 reviewed using the EMMIE rapid evaluation method (Effect, Mechanism, Moderator, Intervention, and Economy). In the rapid evidence review of the academic literature, three phases were defined as existing brownfield activity associated with remediation and redevelopment and developed sites in use.

Empirical links between remediation and sustainable development discovered people may experience increased mortality and morbidity living close to contaminated brownfield, especially in disadvantaged areas, and soil and groundwater quality are improved following remediation. Natural capital is generally improved following redevelopment especially where there is green space e.g. soils, waters, biodiversity.

Social benefits accrue including health and well-being from contaminant reductions, provision of new infrastructure, amenities, housing, access to greenspace and associated increased physical activity (walking from homes located on former brownfield). The carbon footprint for living and working is lower for brownfield sites in comparison to greenfield. Economic prosperity increases including land value, profit, house prices and taxation.

Key findings from rapid evidence reviews were:

  • Links between remediation/redevelopment and sustainable development exist
  • There is a strong policy framework that is currently undergoing change which could be influenced by this and further work
  • Guidance, frameworks, indicators and tools exist which could inform distinct components of a tool
  • Current UK case studies are needed to measure benefits of remediation
  • A range of authoritative data sources exist; these need to be mapped and evaluated for the most relevant indicators
  • There is no 'one size fits all' framework, tool or indicator set available

The team asked: how might we present and monitor the potential benefits of remediation and redevelopment?

Macklin said the team looked at stakeholder mapping, user research and design sprint - a process to have a look at what the solution might look like at the end.

A series of one-to-one informal semi-structured interviews were conducted with key stakeholders to develop user personas (e.g. technical specialist, planner, policy maker etc.), use cases for the tool and user stories based on likely interactions with the tool.

The results of the design sprint showed a spatial based interface as the preferred option, with a dashboard interface, with key indicators identified to create a low fidelity prototype.

The team then asked what semi-quantitative framework could be used to measure pre and post development changes arising from remediation and redevelopment?

Natural capital approach

Griggs said: "we decided to explore how a natural capital approach can help us with developing essentially, an appraisal framework. Natural capital is defined as the elements of nature that produce value to people and is often expressed, expressing flow of services and benefits from the natural system as a logic chain."

Griggs said the natural capital approach is already well used at the EA. "Brownfield land can be conceptualised as a stock, but where it is contaminated, it can be seen as a pressure. So, at the top of this logic chain, there are pressures and drivers of change which may be affecting the quality and quantity of stocks over time, putting additional demands on stocks."

The EA uses natural capital accounting in other areas, so it was safe ground to look at how remediation fits in. "Brownfield land can be conceptualised as a stock, but where it's contaminated you can also think of it as a pressure. So, at the top of this logic chain, pressures and drivers of change which may be affecting the quality and quantity of stocks over time are putting additional demands on stocks.

"The approach helps to recognise and appraise the wider benefits from interventions. This process of considering all the different flows of different benefits forces you to think about wider impacts rather than just taking interventions at face value. It's also encompassing people, nature and the economy.

"We observed that remediation doesn't fit neatly, necessarily, into the logic chain. So, we need some work on the gaps in our understanding of how remediation fits into the approach and the schematic."

Logic chain

Darren Beriro said the team wanted to develop a logic chain in the context of a case study. "The plan was to develop a natural capital logic chain, something that didn’t exist for contaminated soil, water and its remediation in the context of redevelopment. So not as a brownfield site existing as an underused space that may be contaminated and suffer from other issues, but one that was moving through the development framework and process to be reused for housing, recreational space or commercial development.

"We produced an appraisal of natural capital indicators and metrics that are most suitable for land contamination and incorporated those into a new logic chain framework. We then applied that new logic chain framework to a couple of case studies."

The decision was to embed the logic chain into the Natural England capital approach, which looks at natural capital indicators and change. We felt at this stage there could be more credibility and mandate given that approach already exists."

The logic chain framework was applied to two brownfield 'typologies', a military site and a coking works site (which was used in the presentation). It was in a peri-urban area, with 70% sealed surface, 10% semi-natural grassland and 5% woodland. The site was redeveloped for mixed use residential and commercial, and as a public open space with additional garden and water clean-up. Natural capital impacts and indicators were created based on a six-point qualitative system with a primary asset class and a secondary one looking at how it had changed.

Macklin says "It’s very simple, really, with upwards green arrows showing a positive impact and then, on the other end of the scale, negative impacts on ecosystem-services. It indicates the likely scale and direction of impact in service provision post-remediation and redevelopment, with consistent accounting of service provision. Each indicator was worked through for an overall view."


Macklin said that the project showed that demand and need exist for new approaches measuring and monitoring sustainable growth arising from remediation and redevelopment. Proof of concept has demonstrated qualitative assessment can be applied to two typologies of redeveloped contaminated brownfield sites.

"There are important links between remediation and sustainable growth that are not widely recognised in policy and delivery." The project underscores the value of robust brownfield land management, and there is an appetite for change and significant opportunities to transform the perception of contaminated land.

David Griggs said: "I think that there are important links between remediation and sustainable growth that aren’t widely recognised in policy delivery and that some are critical, like biodiversity, climate change and public health and it highlights a significant opportunity to improve how we manage the brownfield resource.

"The proof of concept that we have now, that remediation and natural capital can work together, is positive. It is really useful to have a lot more work done in this space, but it is a complex area and does require and justify more investment and cooperation across the sectors and is right for further work."