Select Committee on European Communities Seventeenth Report



  68.    Article 4 prescribes (very simply) three classes of landfill site-for hazardous,[38] non­hazardous[39] and inert[40] waste. Article 6 prescribes that landfill sites designated for hazardous and inert wastes may respectively be used only for those categories of waste; non-hazardous sites may, however, be used for municipal waste as well "non­hazardous waste of any other origin". Article 5(2) prohibits the use of landfill for liquid waste; explosive, corrosive, oxidising and flammable waste; hospital and other clinical waste; and (with certain exceptions) tyres: we discuss these further below.

  69.    The rigid scheme for the separate use of landfills for hazardous, non­hazardous and inert wastes was challenged by industry witnesses. In particular, there was consistent criticism of the proposed system of single-purpose containment sites ("monofills") for hazardous wastes. Friends of the Earth, however, suggested that if landfill was seen essentially as a storage mechanism, and if the more hazardous types of waste were subjected to pre-treatment, such as vitrification, monofill was preferable to co-disposal (see paragraphs 74 and 83-9) (Q 152).

Hazardous waste

  70.    As drafted, the requirements of Article 6(2) relating to the contents of hazardous waste sites were thought by some witnesses to be ambiguous-even to the extent of permitting the practice of co­disposal to continue. The Commission confirmed to us that this was not the intention: "hazardous waste landfill" would be for disposal of hazardous waste only-ie it could not contain biodegradable materials (Q 286). We find this unsatisfactory: many wastes which are hazardous according to the Hazardous Waste Directive's definition are themselves biodegradable (eg dilute phenolic solutions, oil interceptor contents, or metal salts) in an appropriate environment. Whilst the more reactive materials will decompose in a hazardous waste only site, those which require an active microbial population for their biodegradation are less likely to do so. This is one of the arguments for co­disposal (see paragraphs 83-91).

  71.    The DETR's compliance cost assessment indicates that some 2.3 million tonnes of difficult[41] solid wastes are currently co­disposed, of which about 2.2 million tonnes would be diverted to hazardous waste monofills: disposal of the remaining 0.1 million tonnes would be split evenly between incineration and solidification prior to landfill.

  72.    We note that some hazardous wastes with no leaching qualities (eg asbestos) pose no environmental threat if entombed and securely protected from subsequent disturbance. We see no reason why, subject to the careful controls already in place under UK legislation, such wastes should not continue to be landfilled with mixed municipal waste, thereby leaving more capacity in hazardous monofill sites for disposal of materials which really need to be disposed in them.

  73.    The compliance cost assessment also indicates that between 200,000 and 400,000 tonnes of clinical and similar waste are generated each year in the UK, of which 75 per cent is incinerated and the remainder landfilled. We heard no satisfactory evidence as to how the proportion of clinical waste currently landfilled should in future be dealt with, but in our view the right solution for all clinical waste is hygienic incineration.

  74.    Industry witnesses told us that private sector operators in the UK would be unlikely to provide the hazardous waste only monofills which the change in disposal policy brought about by the Directive would require. We share the industry's concern over the proposals to create a rigid class of hazardous waste monofills, which would provide nothing more than long­term storage for hazardous waste materials, with all that that implies for monitoring and future liabilities. In our view it is essential, if the system is to work at all satisfactorily, that wastes consigned to hazardous sites should be pre-treated, eg by vitrification, to minimise their hazardous properties and, once landfilled, should be the subject of rigid systems of monitoring: otherwise we would regard the practice as fundamentally unsustainable. It is true that pre-treatment of all landfilled waste is a requirement under Article 6, but as we discuss in paragraphs 80-2, the requirement is broadly drafted and in this instance a more prescriptive approach may be called for. It is not clear to us whether additional treatment capacity is currently available or could be made available in time to meet the Directive's requirements.

Liquid waste

  75.    Article 5(2)a would ban liquid waste going to landfill. No definition of "liquid" is given and witnesses found difficulty with the proposal, particularly in relation to sludges. The Water Services Association were particularly concerned about the implications for sewage sludge (some 10 per cent of which currently went to landfill) if public opposition to landspreading (see paragraph 25) were to gain momentum (p 205). The European Parliament has proposed to remedy the situation by defining liquid waste as fluid containing up to 45 per cent solids by weight and with flow characteristics to be determined by the Committee established under Article 16.

  76.    Whilst the amendment proposed by the European Parliament has the merit of providing a measurable criterion, we are concerned that the proposed percentage by weight of solids is very high. Many filter cakes, for example, have a percentage solids content of 30-40 per cent by weight and no flow characteristics whatsoever. As drafted, the amendment would (and is evidently intended to) outlaw the landfill disposal of all sewage sludge, on which the UK depends at present for about 10 per cent of the total amount disposed of in England and Wales-the remainder being mostly spread on land and therefore outside the scope of the Directive. We recommend that if landfill is now longer available, sewage sludge with no recoverable value should in future be incinerated in a carefully controlled manner.

  77.    The compliance cost assessment also indicates that 0.5 million tonnes of difficult liquid waste is currently thought to be landfilled: it is estimated that the proposed ban on liquid waste landfill would require 0.4 million tonnes to be pre­treated prior to discharge to sewer, with the remaining 0.1 million tonnes divided equally between incineration and solidification prior to landfill.

  78.    We were told that the proposed ban on liquid (however defined) waste to landfill would raise problems for the UK, since landfill site leachate is defined as a waste under domestic legislation.[42] It is not entirely clear, however, whether the recirculation of leachate within the landfill site that produces it would constitute a waste treatment process and thus require a waste management licence. Since such recirculation within a landfill effects a considerable reduction in biodegradable content, this needs urgent clarification. In our view this would create an absurd situation for the waste management industry and would undermine the approach which we recommend for dealing with active and closed landfill sites during the implementation period for the measures in Article 5. We therefore recommend that the Directive should expressly permit the recirculation of leachate within landfill sites for the purposes of accelerating biodegradation and optimising methane recovery.

Used vehicle tyres

  79.    The Commission's reasons for proposing a ban on landfilling of used tyres (whole or shredded) were mentioned in paragraph 27. The European Parliament has proposed that all types of tyre should be banned (ie with no exception for bicycle and very large tyres). It remains unclear to us why, if tyres are to be banned, there should be any exemptions. It was suggested to us that whole tyres were useful as drainage blankets for landfills. We are, however, not convinced that there is a case for continuing with this practice. As for disposal, we recommend that tyres should, as far as possible, be shredded and found uses such as being mixed with tarmac for playground surfacing; otherwise incineration may have to be the answer.


  80.    Another significant provision of Article 6 is that "only waste that has been subject to treatment is landfilled". Witnesses questioned whether the definition of "treatment" in Article 2 (see paragraph 26) was adequate; they also questioned why inert waste, or waste which had itself been the subject of pretreatment, should under Article 6 be subjected to "treatment". The Confederation of British Industry (CBI) was concerned that the definition was over-prescriptive (p 148).

  81.    Dr Krämer assured us that the Commission would be adjusting the drafting to clarify that neither industrial waste that is itself the result of a pre­treatment nor inert waste will necessarily require treatment before landfill. The European Parliament has proposed an amendment on similar lines.

  82.    With the amendments now proposed by the European Parliament and indicated to us by the Commission, we are satisfied that the definition of "treatment" in Article 2 is adequate. We note that the definition would already cover incineration, which is of course a form of pre­treatment; we also note that the purpose of the Commission's intentionally broad definition is to encourage the choice of options higher up the waste management hierarchy. (See paragraph 26)


  83.    A major concern of the UK waste management industry is that the requirement to dispose of hazardous and biodegradable wastes separately would deprive operators of the reportedly beneficial effects of co­disposal-the practice of disposing of hazardous and non-hazardous wastes in the same site. This was reinforced by the evidence from the IWM, the Environment Agency and Imperial College Centre for Environmental Control and Waste Management (QQ 6-8; pp 7, 39, 160-2).

  84.    The DETR explained to us that acceptance by the then UK Government that co­disposal should be phased out was an essential part of the package at the time of the 1995 Common Position (see paragraph 20); it was not expected that the position would change in the present negotiations (Q 163).[43]

  85.    Whilst the Government's stance in the Council may be motivated primarily by the need to secure a political consensus, the evidence in favour of co­disposal is in fact not entirely clear­cut. According to the Environment Agency, the United Kingdom has spent some £10 million on co­disposal research, which has demonstrated the environmental benefits of the approach. Other evidence reflected a widespread conviction amongst the industry that co­disposal was a sound practice which contributed to the chemical transformation and immobilisation of hazardous materials and substances co­disposed with biodegradable waste. Whilst specific detail was not forthcoming, we found that the industry's evidence pointed to a number of beneficial effects of co­disposal.

  86.    The evidence left us with some uncertainty about the status of the "flushing bioreactor" concept-an approach based on providing controlled conditions in which leachate is mechanically recirculated through landfill waste so that it breaks down more rapidly and evenly. The DETR's most recent guidance on landfill operation (DOE Waste Management Paper 26B)[44] is concerned with encouraging this mode of operation, and the EA told us that it was regulating landfills in a way which would encourage their operation as flushing bioreactors. The Commission, however, clearly believed that the flushing bioreactor was merely a concept-Dr Krämer told the Sub-Committee that he did not believe that one existed. Recirculation of leachate is, in fact, standard practice in modern UK landfill sites: the Sub-Committee visited an example of such a site in Fife, where the site leachate is routinely recirculated by irrigation beneath the surface cap.

  87.    Whether or not the flushing bioreactor can be said to exist, what is not in dispute is that the ban on co-disposal would ipso facto rule it out for the future, since under UK law (as we have already noted) landfill leachate is defined as a liquid waste and would therefore be banned from recirculation by the Directive, unless our recommendation in paragraph 78 is accepted.

  88.    Whilst the position previously reached, and likely to be reached again, by the Council of Ministers could be explained in terms of political expediency rather than rational argument, it is legitimate to apply the precautionary principle[45] here. All landfill sites, including those designed to be "containment" sites, have the potential to fail and cause damage to the environment. They raise problems with long­term monitoring and the question of ultimate responsibility.

  89.    Nevertheless, co­disposal is itself a form of treatment in situ. We recognise the widespread view of the UK industry that the process of co­disposal, by assisting (and in the case of the bioreactor accelerating) decomposition and by neutralising certain hazardous components of waste, is environmentally beneficial. We also note that research by the Department of the Environment and the Environment Agency has supported these claims. We believe that to replace the co­disposal of industrial and biodegradable wastes with a rigid system of segregation and monodisposal of hazardous industrial wastes is to fail to recognise that judicious and carefully regulated mixing of certain low-hazard industrial wastes (eg organics) with biodegradable municipal waste (which can itself contain a range of hazardous materials) is unlikely to produce an end result materially different from that of a purely municipal landfill.

  90.    We recognise that the management and aftercare of sites currently operated on flushing bioreactor principles will have to be approached with care. On the basis of the available evidence, we are doubtful whether the processes within a flushing bioreactor are capable of precise specification or their effects measurable with any certainty. The principle, however, of recirculation of leachate and otherwise maintaining optimum conditions for progressive decomposition, coupled with collection and use of landfill gas, within existing mixed waste sites should, in our view, be supported. We note that the Royal Commission on Environmental Pollution in 1996 recommended that the Department of the Environment and the waste disposal industry should consider how the flushing bioreactor approach could be made financially attractive both then and after co­disposal of industrial wastes ceased.[46] This recommendation, in our view, remains valid for the management of existing co­disposal sites, even if no new ones are constructed during the implementation period for Article 5 of the Directive, and should continue to be the subject of research.

  91.    We recommend that one of the principal management aims of all sites which currently take (or have until recently taken) significant quantities of industrial and biodegradable waste should be to optimise methane recovery for as long as the process remains viable. Such a measure would be consistent with the Commission's communication on methane reduction and would help to reduce the timescale within which such sites pose a threat to the environment.

38   "Hazardous waste" is defined by reference to the list published in pursuance of Article 1(4) of the 1991 Hazardous Waste Directive (91/689/EEC, OJ No L377, 31 December 1991, p20, as amended by Directive 94/31/EC, OJ No L168, 2 July 1994, p28). The list was established by Council Decision 94/904/EC (OJ No L356, 31 December 1994, p14). Back

39   Defined as any waste which is not hazardous or inert. Back

40   Defined by Article 2 as "waste that does not undergo any significant physical, chemical or biological transformations. Inert waste will 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. The total leachability and pollutant content of the waste and the ecotoxicity of the leachate must be insignificant." Back

41   The term "difficult waste" has no statutory meaning, but is a well-understood term used by the waste management profession to describe wastes which are in one way or another problematical. Back

42   The Waste Management Regulations 1994. Back

43   Mr Meacher told the European Standing Committee A that although the UK still believed that co­disposal was a sensible way of dealing with hazardous waste, "hardly any other Member State holds that opinion, and we must take account of their views....We have done our best to persuade other Member States otherwise....Despite the forcefulness of my logic, those beliefs did not carry at the Council. We must take account of the fact that we may not succeed." Back

44   Department of the Environment, Waste Management Paper 26B, Landfill Design, Construction and Operational Practice, The Stationery Office, 1995 (2nd impression 1997). Back

45   The avoidance or the reduction of risks to the environment by prudent action taken before any serious problem is encountered: a translation of Vorsorgeprinzip (a principle of German environmental law), which has been employed by the Royal Commission on Environmental Pollution from its Tenth Report (1984) onwards. It is also reflected in the language of the UN Framework Convention on Climate Change, agreed in Rio in 1992, and in other environmental policy documents. It is to be distinguished from the "prevention principle" of EC environmental policy, eg as formulated in the action programmes, which has the more concrete sense of preventing pollution at source (to avoid subsequent retrofitting). For a discussion, see RCEP 12th Report, Best Practicable Environmental OptionBack

46   RCEP 19th Report, op citBack

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