Development of a risk assessment model for diffuse landfill pollution as a result of climate change.

Abstract

Historically, landfill sites have been situated proximal to river banks in fluvial, estuarine and coastal settings, with over 20 bankside landfills on the tidal River Thames alone. With the IPCC predicting that storm intensity, sea level rise and precipitation are to increase, these sites will be exposed to increased levels of erosion and saline inundation. Increased salinity may result in changes to contaminant partitioning and hence mobility, whilst bank collapse could result in the release of contaminated sediment into surrounding waters. To date, there have been no studies examining this diffuse pollution threat and there is little understanding of the impacts of climate change on these bankside landfills.

The specific objectives of this work are to characterise levels of contamination and contaminant mobility in two coastal landfills, providing a baseline for further laboratory work and to identify potential areas of leachate breakout and evidence of bank collapse.

The study sites are Newlands Landfill (a land-rise engineered site opened in 1954) and Two Tree Island (opened in 1980, engineered as a sea wall defence), Essex. Site walkovers and sample collection will take place in in January 2012. This study will report findings from the initial survey, as well as presenting analytical data from collected wastes and sediments. The parameters to be tested are heavy metal content and mobility, sediment pH, TOC and moisture content; determined using ICP, Flash Elemental Analyser and ASTM leach tests.

Future work will examine the potential for contaminant release under climate change scenarios including increased salinity, rainfall and erosion events. These findings will be incorporated into a Risk Assessment model to quantify the risks associated with diffuse pollution resulting from climate change.