Gas in Waste Issues

Work by Southampton University (e.g. Beaven et al 2007 (see ref below), Powrie et al, 2005) indicates that the presence of landfill gas in saturated waste can cause effects such as:

• Foam (leachate and gas mixtures) in wells and unrepresentative leachate levels (unless pressure dippers are used);
• Reduced drainable porosity, as gas occupies some of the void that would otherwise be filled with leachate. This means leachate levels could over-predict the volume of leachate to be removed from the waste.
• Truly saturated waste may not occur if gas occupies some of the void. This could make the waste appear damp rather than saturated in drill logs.

Nick has some experience in this relatively new area of understanding the impacts of landfill gas in waste.

Beaven, R.P., Cox, S.E. and Powrie, W. 2007, Operation and Performance of Horizontal Wells for Leachate Control in a Waste Landfill. Journal of Geotechnical and Geoenvironmental Engineering. Vol.133, no.8 (See Reference #24 on Downloads page).