BY KATIE - MYGREENPOD, 28 Aug '18

Researchers find new way to identify the coastal landfill sites that pose the greatest risk of pollution

Researchers from Queen Mary University of London have developed a new screening assessment method that can identify which historic coastal landfill sites pose the greatest pollution risk.

The first-of-its-kind method can be applied at a regional or national scale for minimal cost using existing datasets, and can help coastal managers to prioritise which sites require the most urgent attention.

England’s coastal landfills

In England alone there are over 1,200 historic landfill sites in low-lying coastal areas, of which more than a third are located near designated ecological sites. Several sites are located near the Thames estuary.

Some of these sites, constructed prior to modern environmental regulation with little monitoring or control of waste content, have already started to erode. Climate change effects, such as sea level rise and more intensive storms, are likely to increase the number of eroding sites.

Historic waste can include materials that are physically or chemically harmful to ecological and public health such as asbestos, microplastics, heavy metals and hydrocarbons at concentrations that significantly exceed environmental quality guidelines.

Previous research has shown that strategies to mitigate the risk of pollution from such sites can be prohibitively expensive.

Risk index for landfill sites

The research, authored by Dr James Brand and Professor Kate Spencer from Queen Mary’s School of Geography, is published in the journal Anthropocene Coasts.

The method determines an overall risk index for each landfill site by considering how likely it is the site will erode and whether sensitive environmental sites may be exposed to any waste that is released. This is done using a variety of parameters.

Factors such as wave exposure, the likelihood of flooding, the presence of flood defences and the type of waste the site contains – as well as the proximity of ecological sites – are given severity scores that allow an overall risk score to be calculated. This score then allows coastal managers to prioritise the sites that pose the greatest pollution risk.

1/10 coastal landfills at risk of erosion

Dr James Brand, Research Fellow at Queen Mary and lead author of the paper, said historic coastal landfills ‘are increasingly likely to erode and release waste into the environment’, adding that ‘funding for remediation works is limited.’

‘The proposed method supports coastal managers by identifying which sites should be addressed first to minimise the risk of pollution occurring’, Dr Brand added.

The method was tested on a small number of historic coastal landfills in south east England. Kate Spencer, Professor of Environmental Geochemistry at Queen Mary’s School of Geography, said this provided a snapshot of the sites that pose the greatest risk of environmental pollution.

‘Our previous research revealed that nearly one in 10 historic coastal landfill sites in England are at risk of erosion’, Kate added. ‘This view could change – for both better and worse – with policy interventions, enhanced coastal protection and with increased predictions for sea level rise.’