Dr Jan Gronow

Landfill Policy Manager

Environment Agency

Rio House, Waterside Drive, Aztec West,

Almondsbury, Bristol BS32 4UD

Tel: +44 1454 62 4079 Fax: 62 4470

e-mail: jan.gronow@environment-agency.gov.uk

In 1994 the concept of landfill completion was introduced into waste management regulations in the UK. Operators are no longer able to surrender their site licences until regulators are satisfied that the condition of the site is such that it is unlikely to cause pollution. Before surrender, the operator is responsible for the maintenance and monitoring of the site and any pollution that the site might cause. Guidance was provided to regulators on how to interpret completion and it was estimated that the time for a household waste site to reach completion was likely to be greater than 100 years.

In order to accelerate stabilisation, the concept of the bioreactor landfill was advocated but has only been taken up in a few landfills and then only partially. The reason for this is explored. The Agency’s attitude to the interpretation of completion has developed since 1994. It is now considered that, once active control systems have been switched off, then if emissions are not unacceptable (a legal term) and are unlikely to increase, then surrender of the licence can be accepted. The determination of what is acceptable is not easy but not impossible.

However, the determination of the likelihood of increased emissions depends to a considerable extent on a knowledge of the degree of waste biodegradation that has occurred. Probably one of the best ways of ensuring that the majority of the waste in a site has the opportunity to degrade, is to operate the site using bioreactor techniques and to monitor emissions regularly until they start to decrease. Although the criteria for determining landfill completion have been relaxed somewhat since 1994, achieving them within the time-span of a generation (say 30 years) still depends on accelerating the stabilisation of the site. It has been suggested that achieving landfill completion within a generation desirable and is a definition of sustainable landfill. This will be discussed.