Sustainable Remediation – The role of the geotechnical specialist

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Let’s get some harsh truths out of the way first. Remediation is not necessarily sustainable. Excavation and disposal (ok, ok – dig ‘n’ dump) is sometimes the most sustainable option. Remediation is usually an enabling part, not the main purpose, of a project. And finally, choosing the sustainable remediation option is neither difficult nor costly.

July 2017 saw the publication of the first international standard on sustainable remediation. In September this was adopted as a British Standard: BS ISO 18504:2017. This short and even readable document begins once the risk assessment has concluded that remediation is necessary. Risk reduction objectives and overall constraints need to be established. The conceptual site model is then used as the basis for short listing technically feasible remediation strategies that will eliminate and/or control unacceptable risks in a safe and timely manner given constraints such as space, budget or other activities. Of those shortlisted strategies, the remediation strategy that is judged to be the most sustainable is the one that reduces the risks whilst optimising the environmental, social and economic value of the work.

In practice choosing the most sustainable of, say four, short listed strategies can be a simple affair. Each of the candidates is compared with every other for their relative performance in terms of environmental, social and economic effect – be that positive or negative. Often a clear winner emerges at this point – job done!
Occasionally there is no clear winner and a deeper consideration of effects is needed. In this case a set of site specific factors, or indicators, that delve deeper in to the environmental, social and economic dimensions are chosen to compare the effect of each strategy. Again simple qualitative comparisons will often identify a clear preferred strategy. Only in very rare circumstances will recourse to a much more sophisticated, costlier, fully quantitative comparison – perhaps based on Life Cycle Analysis approaches – be necessary.
BS ISO 18504:2017 seeks to improve the process of choosing a preferred remediation strategy. Once one has been selected, it can still be value engineered to reduce costs and ‘greened’ to reduce environmental impact.

The best way to test out BS ISO 18504:2017 is perhaps to consider a recent remediation project you have been involved in and see how consideration of the social, environmental and economic effects could have been taken in to account. It’s not that hard or time consuming.

Article contributed by Paul Nathanail, Managing Director of Land Quality Management Ltd and Chair of ISO Working Group on sustainable remediation.

This article was featured in the May/June 2018 issue of the AGS Magazine which can be viewed here.