Select Committee on European Communities Seventeenth Report



  35.    As we have seen, Article 1 of the Directive aims "to prevent or reduce...negative effects on the environment...from landfilling of waste". Some witnesses criticised the Directive for being based on the premise that the effects of landfill were by definition "negative", in particular the Local Authority Waste Disposal Companies Association, who described it as "blind prejudice" (p 162), and the Environmental Services Association (ESA), (p 89). However, it seemed right to enquire of witnesses how seriously they felt landfill posed risks for the main environmental receptors-water, soil and air (cf table at paragraph 8).

Surface and groundwater pollution

  36.    We received conflicting evidence on the impact of landfill operations on groundwater quality. The Environment Agency told us that there had been few significant incidents of pollution from landfills in England and Wales; while Friends of the Earth took an opposing view (Q 130; p 51). The Scottish Environment Protection Agency (SEPA) believed that with careful siting, good design and good practice, landfill was not a significant pollution risk: groundwater monitoring had always been limited in Scotland, since only about 4 per cent of Scottish drinking water supplies came from groundwater, but such pollution as had occurred was thought to be due mainly to older, unlined landfill sites. Far more significant was the pollution of aquifers by hydrocarbons, nitrate from agricultural sources, ferruginous minewater and saline intrusion from over-pumping (pp 185, 190-1). Dr Krämer, for the Commission, said: "Whenever groundwater is examined, the biggest source of contamination is found to come from landfills." He also spoke of "ticking timebombs" (QQ 275, 278).

  37.    We note the considerable body of research conducted by the Department of the Environment during the 1970s (known as "the Brown Book"), which was focused on the effects of landfill disposal on groundwater quality: this recorded that extensive experience in the UK over a long period of time had shown very few documented cases of significant groundwater contamination resulting from landfill sites.[27] Nevertheless while concluding that the natural processes of dilution and attenuation were effective in mitigating the effects of groundwater contamination by landfills, the research did record incidents of both ground and surface water contamination. We were told by English Nature of serious ground and surface water pollution at Holt Heath National Nature Reserve in Dorset, which was due to an adjacent and now closed landfill (Q 52).

  38.    Research into groundwater quality in the UK has continued, and the Environment Agency drew our attention the conclusion of its 1996 report on groundwater pollution in England and Wales: "Categories of land-use activities which present the greatest threat to groundwater quality have been identified. Landfill sites are numerically the most significant category, but in terms of their actual and perceived impacts on groundwater are considered to be somewhat less of a problem than other sources and types of pollutants. The data collected is [sic] biased towards those land-use categories which are highly regulated and therefore likely to be better monitored. It is therefore not surprising that waste disposal activities are so prominent in the study."[28] The Agency also emphasised that of the reported occurrences of groundwater contamination due to waste disposal, half were concerned with suspected contamination only (p 22).

  39.    The Agency made the point that since the introduction of the 1994 Waste Management Licensing Regulations, landfill sites had been subject to statutory minimum frequencies for leachate and groundwater monitoring (Q 11).

  40.    We asked the Agency to comment on Dr Krämer's remarks and the apparent discrepancy in the evidence. In response, it highlighted some important differences between the situation in the UK and that in some other Member States: "Long before the introduction of site licensing in 1976, we have benefitted from planning and other legislation that has sought to control the siting of waste management and other facilities in order to protect the local environment, particularly water resources. Several of our European partners have neither benefitted from such legislation nor have they fully implemented the Waste Framework Directive....Consequently some, including Germany, have experienced major pollution incidents as a result of poorly controlled landfill operations. Such experiences have caused a tendency to reject such practices as bioreactive sites and co­disposal, to over­regulate and to shy away from a risk­based approach to regulation" (p 22).

  41.    Dr Krämer's concern may well be justified in relation to landfill in parts of continental Europe, but we are satisfied that the high standards of monitoring and regulation developed over the years by the Environment Agency, by its predecessor the National Rivers Authority and by the equivalent bodies in the rest of the United Kingdom, coupled with the important safeguards provided by the planning system, have been effective in minimising the risks to groundwater from landfill.

  42.    As we were told by the Geological Society and the British Geological Survey, no landfill site, however well engineered and lined, can be expected to retain its integrity indefinitely (QQ 194-6). Ultimately all landfills will leak. In the case of active sites, strict containment, monitoring and leachate control, together with a capacity on the part of the operator to deal with emergencies, should be sufficient to prevent groundwater pollution, and we note that the provisions of Annex III to the Directive would effectively extend to other Member States a régime comparable that of the UK 1994 Waste Management Licensing Regulations. It is the long­term position that concerns us, and particularly the Directive's proposals for the long-term storage of hazardous material in hazardous waste only sites. We were told by the Environmental Services Association that its members were seriously concerned that the required Certificates of Completion would not be forthcoming for such sites, which could mean that the operator would retain liability indefinitely (see paragraphs 102-6).

Soil contamination

  43.    We received little evidence on the impact of landfill on soil contamination. In their written evidence, Friends of the Earth referred to almost 6500 closed landfills in the UK and subsequently told us that the total number of former landfills was unknown (p 51; Q 136). This was consistent with the findings of the Royal Commission on Environmental Pollution (RCEP) in its 19th Report, Sustainable Use of Soil.[29] The RCEP also recorded that there could be of the order of 100,000 contaminated sites in the UK and that former landfills were the most numerous category of such sites.

  44.    Considering that greater emphasis should be placed in future on preventing pollution of soil, the RCEP recommended that the Department of the Environment should pave the way for the eventual segregation of wastes and phasing out of landfill based on the practice of co­disposal (see paragraphs 83-91). The last Government, in its response to the RCEP's Report,[30] took the view that carefully controlled co­disposal remained an acceptable way of disposing of certain industrial wastes. For this reason, the DETR told us that Ministers were concerned about the Directive's proposed ban on co­disposal (Q 163).

  45.    We are concerned at the lack of useful statistics relating to land which has been contaminated by past landfill activities, although this is an inevitable legacy of unregulated times. We note that the provisions of the Environment Act 1995 for contaminated land registers remain unimplemented. We would hope that the possibility of implementing those provisions will be given careful consideration in the Government's current review of waste management policy.

Air pollution

  46.    One of the products of the anaerobic decomposition[31] of biodegradable waste is landfill gas-a mixture of about 60 per cent methane and 40 per cent carbon dioxide (CO2), with small elements of others (eg hydrogen sulphide). Both are important greenhouse gases-ie gases which, in the atmosphere, absorb thermal radiation emitted from the Earth's surface and have a blanketing effect upon it, thus contributing to global warming. A key question raised in the enquiry was whether the proposals in the Directive were the most effective way of reducing the contribution which current landfill practices made to global warming.

  47.    We received conflicting evidence as to the relative contributions of CO2 and methane to global warming-ie their "global warming potential" (GWP). If the GWP of CO2 is taken as 1, the estimates of the GWP of methane which we received ranged from 8 to 70. The value of the GWP attributed to methane depends upon the time horizon which is assumed, and according to evidence from Professor Porteous the range of values just quoted would represent an inverse range of time horizons of between 500 years and 20 years respectively (p 177). Methane in the atmosphere is destroyed by chemical reaction with hydroxyl (OH) radicals: it decays more rapidly than CO2, but is considerably more damaging than CO2 initially because of the GWP factor.

  48.    In a report for the Environment Agency, consultants W S Atkins have suggested that the life of methane in the atmosphere is 12 to 17 years, compared with CO2 at 500 to 2,000 years.[32] On this basis it is logical to assume a GWP for methane towards the higher end of Professor Porteous' 8-70 range of values, ie using the shorter time horizon. The Atkins report also cites evidence that stabilisation of current atmospheric methane concentrations could be achieved by a reduction of 10 per cent of annual global anthropogenic methane emissions. There are therefore sound policy reasons, notwithstanding the scientific uncertainty, for tackling methane first, rather than carbon dioxide, when seeking to reduce the contribution which landfill operations make to global warming.

  49.    The Commission's Communication on a strategy for reducing methane emissions (COM(96)557 Final, 15 November 1996) identified landfills as accounting for about 32 per cent of known methane releases in the European Community. The Communication also found that the collection of methane through highly efficient systems was a cost-effective means of reducing emissions: "These options (energy generation or flaring) would eliminate either completely (up to 100 per cent) or almost completely (up to 95 per cent) the harmful effects of methane gas emitted from landfills".

  50.    The Commission's conclusion is broadly in accord with the Environment Agency's evidence-that instantaneous efficiencies of 90 per cent are achievable at modern landfills for the collection of landfill gas, but that to allow for older sites an average efficiency of 80 per cent is realistic; and that an overall reduction of emissions of 80 to 90 per cent is achievable by modern controls at landfills (the W S Atkins report estimated that efficiencies of over 90 per cent were achievable by this means).

  51.    This evidence was, however, contradicted by Dr Krämer, who told us that the Commission's research showed that 90 per cent efficiency of methane capture from landfills was unattainable: he said a more realistic optimum would be between 60 and 70 per cent, although normally it would be much lower (Q 284). Information subsequently submitted by Dr Krämer in support of his assertion, in the form of a paper by Hans Willumsen of LFG Consult, Denmark, states that only about 25 to 50 per cent of the gas produced in landfills is recoverable.[33]

  52.    Referring to a report produced by the Energy Technology Support Unit, Harwell (ETSU), for the Department of Trade and Industry,[34] Friends of the Earth told us that landfill gas schemes currently in operation were unlikely to capture more than 50 per cent of the gas (Q 155). The ESA, on the other hand, referred us to the W S Atkins report as containing the most up to date and reliable estimate of the efficiency of landfill gas recovery (p 109).

  53.    The ESA also argued that landfill acted as a carbon sink, "locking in" some 30 per cent of the carbon in municipal solid waste (MSW); whereas if it were incinerated, the carbon would be emitted as carbon dioxide (CO2). Professor Porteous, however, claimed that Energy from Waste (EfW) incineration effected a net greenhouse gas reduction by eliminating landfill methane emission and by displacing (ie substituting for) CO2 emitted from energy generation direct from fossil fuels.

  54.    The lack of consistent data on these key issues-the efficiency of methane capture in landfill and the relative GWP of methane and CO2-substantially weakens what has been one of the main arguments of the principal UK witnesses-that the Directive would not achieve reductions in methane emissions in the most effective manner. In particular, we wish to draw attention to the apparent discrepancy between Dr Krämer's evidence and the assumptions in the Commission's methane reduction strategy (paragraphs 49-51). The only possible conclusion is that, on the basis of the evidence received so far, the Global Warming Potential issue remains unresolved: the comparative environmental benefits of engineered methane recovery from landfill as opposed to upstream avoidance of methanogenesis remains a matter of conjecture. It is therefore important that research on the matter should continue. We note, however, that the Royal Commission on Environmental Pollution, in its 1993 Report on Incineration of Waste,[35] based its conclusion in favour of incineration of municipal waste (see paragraph 141) on the conservative assumption that only 40 per cent of landfill methane would be captured .

  55.    As we conclude in Part 4, when discussing the waste management hierarchy, there is no overriding science-based principle to determine choices objectively between different waste disposal options. Nevertheless, the fundamental aim of sustainability is that it is better to prevent, reduce and recycle waste than to burden the environment with waste in the crude form in which it is generated or discarded by the consumer. We see no contradiction between our recommendations on the desirability both of maximising methane recovery from landfill sites (paragraph 91) and of using incineration with energy recovery (paragraph 144): in both cases it is a question of finding the BPEO which best suits the particular circumstances and makes best use of the opportunities offered.

27   Department of the Environment, Report of the Co-operative Programme of Research on the Behaviour of Hazardous wastes in Landfill Sites, DoE, 1978. Back

28   Environment Agency, Groundwater Pollution: evaluation of the extent and character of groundwater pollution from point sources in England and Wales, 1996. Back

29   RCEP 19th Report, Sustainable Use of Soil, Cm 3165, HMSO, February 1996. Back

30   Sustainable Use of Soil: Government Response to the Nineteenth Report of the Royal Commission on Environmental Pollution, HMSO, C0428, January 1997. Back

31   ie decomposition without the presence of oxygen. Back

32   W S Atkins Environment, Methane Emissions from Different Landfill Categories, March 1997. Back

33   Willumsen H (1997), Production and Use of Landfill Gas: Energy Recovery, paper for International Conference on Solid Waste Management and Technology, Associacão Portuguesa para Estudos de Saneamento Básico, Lisbon, 8-10 October 1997, LFG Consult, Houlkjarshojen 9, DK-8800 Viborg, Denmark. Back

34   ETSU, Landfill Gas Development Guidelines, 1996. Back

35   RCEP 17th Report, Incineration of Waste, Cm 2181, HMSO, May 1993. Back

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