The Landfill Directive: What Next?
Implications for mineral site restoration
by Alan Potter
For the past decade the prospect of the Landfill Directive has been viewed with trepidation by the UK waste-management industry, however the Landfill Regulations 2002 have now brought the directive into force in England and Wales. The principal area explored in this article is the effect of the directive on mineral site restoration.
What the directive requires
The principal requirements of the directive can be summarized as follows:
Biodegradable municipal waste diversion
Statutory targets have been set for a reduction in the landfilling of biodegradable municipal waste.
Restrictions on inputs to landfill
Landfills are to be classified as inert, non-hazardous or hazardous. In effect a three-tier system will be introduced depending on the nature of the waste being handled. An important point to note is that the directive’s technical committee is currently negotiating the technical criteria and methods to be applied to define inert, non-hazardous and hazardous wastes, which will then determine a waste’s suitability for acceptance into particular classes of site. In order to ensure the classifications are complied with three levels of monitoring of waste inputs to landfill are prescribed.
Certain waste types are banned from landfills including a total ban on liquids. Sludges will still be permitted but the precise distinction between a liquid, slurry and sludge is still to be determined.
There is a general requirement to treat all waste prior to landfilling, subject to a caveat on inert waste and certain other wastes.
Landfill Directive permits must be obtained for all operational sites. These will define a range of design and operating parameters, some of which are prescribed in the directive itself.
Operators will have submitted site-conditioning plans that show how existing sites that are to continue to operate will meet the site-specific requirements of the directive.
Financial provision will have to be made for all sites to ensure that the obligations (including after-care provisions) arising under the permit are discharged and that the closure procedures are followed.
What does this mean for the quarrying industry?
A recognized form of restoration of mineral workings is the deposition of waste materials to backfill the void created. This is the origin of the landfill industry in the UK and many minerals sites rely on the availability of waste to achieve the requirements of planning permissions to backfill extracted areas on a progressive basis. The recent experience with the landfill tax and the loss of inert waste to sites that are exempt from waste-management licences brought the issue into stark relief. In this case the Government was able to respond to the calls of the mineral extraction industry to level the playing field, and through this the exemption for inactive waste for restoration was introduced.
However, the threat to supplies of inert waste is now renewed by virtue of the stringency of the directive’s definition. The Landfill Regulations state that waste may only be accepted at an inert landfill site if it is either listed in the following table or otherwise falls into the definition of inert waste.
- Waste glass-based fibrous materials
- Glass packaging
- Tiles and ceramics
- Soil and stones, including naturally occurring sands and clay but excluding topsoil and peat.
The definition of inert waste is simply lifted from the directive into the regulations but is presented as an inclusive three-point test, as follows:
Waste is inert waste if:
- it does not undergo any significant physical, chemical or biological transformations.
- it does not dissolve, burn or otherwise physically or chemically react, biodegrade or adversely affect other matter with which it comes into contact in a way likely to give rise to environmental pollution or harm human health.
- its total leachability, pollutant content and the ecotoxicity of the leachate are insignificant, and in particular do not endanger the quality of surface water and/or groundwater.
What will this mean in practice?
The latest draft guidance document presents the proposed position on waste-acceptance criteria put to the European Technical Adaptation Committee (TAC). This suggests that for the listed wastes to be admitted without testing at a landfill for inert waste, the waste will either need to be a single-stream and single-source material; or, where different wastes contained in the list are mixed together, they must be from the same source.
The key criteria will be knowledge of the source of the waste.
Where there is any doubt about the ‘inertness’ of the waste, even if it is listed, basic characterization testing will need to be applied if it is to be considered for acceptance at an inert site. Such testing will involve the use of percolation tests to establish whether the waste meets the specified leaching limit values for the parameters shown in the table above.
Where a waste stream is not a one-off, compliance testing will need to be carried out at least once a year for each individual waste stream. It can only be dispensed with where the waste is definitely listed as not requiring testing, is known not to contain constituents of concern, or where testing is impractical or appropriate testing procedures and criteria are not available.
A de minimus policy will be applied based on an assessment of the risk that the presence of potentially contaminating materials pose, such that disposal in another class of landfill is more appropriate. Clearly, the matter of determining the relative risks on a load-by-load basis will be subjective, but it seems that a more stringent approach will be applied than that used by Customs & Excise in distinguishing between inactive/ active loads under the landfill tax.
In order to preserve the option of inert waste landfilling either very stringent waste-acceptance procedures will need to be put in place or inert waste supplies will need to be specifically sourced. An alternative is to seek a classification as ‘non-hazardous’, relying on the ability to risk assess away the need for groundwater protection measures.
Operators have made their opening gambit in the site conditioning plans that have been submitted and, in the light of the above, the general expectation is that there will be very few dedicated inert waste sites. However, somewhat surprisingly, the latest figures for site conditioning plans received by the Environment Agency indicate that the inert classification has been sought for around a third of the landfill stock (c. 380 sites). How many of these sites actually prove to be able to meet the stringent requirements remains to be seen. The crunch will come when the sites are brought forward into the PPC permitting regime (sometime between now and October 2007) or when the waste acceptance criteria come into effect (possibly 2005), whichever is the earlier. A critical issue will be how far the definition will be applied and enforced in relation to the activities currently exempted from licensing. If it isn’t, waste may haemorrhage out of the permitted site system as occurred when the landfill tax was first introduced.
Golder Associates supported the Environment Agency in negotiating waste-acceptance criteria within the EU Technical Adaptation Committee dealing with the Landfill Directive. For an informal discussion on the contents of this article or further information on the Landfill Directive, call Alan Potter on tel: (01628) 586212.