Webinar 34 | CReDiT - Carbon reduction tools to support sustainable remediation and earthworks on brownfield sites

Brownfield remediation typically involves major earthwork movements, the use of rapidly reducing resources (topsoil) and the potential reuse or disposal of large quantities of contaminated material. The remediation process and development frameworks are not optimised for achieving sustainability targets, often favouring cost and time-savings over carbon reduction.    There is, therefore, a need to optimise brownfield remediation to significantly reduce the carbon footprint of the process.

This issue was addressed through a collaborative project between the University of Surrey and LEAP Environmental to develop a carbon tool to evaluate the carbon dioxide generated from different site remediation options. This tool promotes greater understanding of the impact of remediation processes on carbon emissions and sustainable site material use.  CReDiT was developed for the dominant remediation method used on residential sites within the UK, namely excavation and cover. This tool determines carbon emissions from the processes involved in this type of remediation, e.g. excavation of soil, the use of raw materials, the transport of material, the recycling and reuse of materials and landfilling of waste.

The starting point for any remediation is a good site investigation and conceptual site model. Following this, in remediation design the sites are typically zoned into areas reflecting different geologies, contamination and potential remediation options (such as excavation and cover depths). CReDiT evaluates the carbon emitted by the processes in site remediation and the materials used. A key issue was understanding and simulating the complex flow (movement) of materials on a remediation site. Different fractions of excavated material have potential reuse or reprocessing options during the remediation process.

The presentation will detail the developed model and demonstrate its application to a number of case studies. The tool provides a quick evaluation of different remediation options, and the carbon impact of material movement, clearly demonstrating potential carbon savings.

The webinar will be presented by Emma Hellawell, Principal Consultant, LEAP Environmental.  Emma is a Chartered Civil Engineer with over 25 years of experience in academia, civil engineering consultancy and local government. Her research in environmental engineering includes modelling contaminant transport, analysis of brownfield contamination and development of carbon tools. She has worked as a local government contaminated land officer and on major civil engineering projects such as the Millennium site. She is now a Principal Geoenvironmental consultant at Leap Environmental, where she is developing tools to evaluate the carbon footprint of foundations for new housing projects, remediation design and earthworks.