Waste Stabilisation

Waste stabilisation in landfills affects four main areas:

1. Whether the waste is sufficiently ‘wetted-up’ to generate landfill gas in sufficient quantities and quality to make power generation and sale a commercial proposition;
2. The quality of leachate that will need to be tankered off site for treatment or that can be treated on site using e.g. reverse osmosis. It therefore affects leachate treatment disposal options and costs and on-site treatment design and operational costs.
3. The results of the site’s hydrogeological risk assessment when the software LandSim is used. This is due to a declining concentration of leachate being spread out over time and distance by dispersion.
4. The period of active control and aftercare monitoring that will be required before a site can be deemed to pose no further significant risk to the environment and financial provision can be released.

Nick undertook a review of waste stabilisation processes as part of a landfill tax funded project for Grantscape (See Reference #17 on Downloads page) in 2003-5 and has examined evidence for waste stabilisation at a number of sites, largely in support of hydrogeological risk assessments, but also as part of leachate management plans.

In 2011, Nick carried out a R&D project for a waste contractor examining empirical evidence for waste stabilisation at three landfill sites. Results were encouraging at two sites, whereas uncertainties prevented clarity at a third. Since 2012, Nick has used waste stabilisation assessments in hydrogeological risk assessments of landfill for FCC, Caird Bardon (Aggregate Industries) and Natural Resources Wales. Further R&D is planned for 2018 with the waste contractor client from 2011.