Volume 6: Human Health, 1989-96
10.
Pollution control and waste management
Discussion
Preliminary questions
Relevance of existing experience in disposing of animal waste
How MAFF handled BSE carcasses and waste
What could have been done differently?
Who could have taken the lead?
Spreading of blood and slaughterhouse waste
Lessons from these aspects of BSE
10.149 We asked ourselves two preliminary questions as a context for assessing the adequacy of the action taken in relation to BSE risks in waste material First, how apt were the existing regulatory arrangements on waste for coping with an agent like BSE? Second, what markers were put up by the various expert committees about the need to give careful attention to waste as a pathway of transmission?
1. The regulatory arrangements already in place
10.150 It is plain from the contemporary criticisms, and major reorganisation of responsibilities and powers that ensued, that at the time BSE emerged the existing arrangements covering waste disposal under the Control of Pollution Act 1974 were not working well. Discussing the disposal of solid waste, the Select Committee on the Environment in 1989 observed:
Never, in any of our enquiries into environmental problems, have we encountered such consistent and universal criticism of existing legislation and of central and local government as we have during the course of this enquiry.
10.151 The system was at the same time having to be adapted to meet EU requirements designed to ensure waste was recovered or disposed of without endangering human health or harming the environment and to apply the principle of 'producer pays' to disposal costs.
10.152 Thus, the task of disposing safely of BSE carcasses and SBO took place within a regulatory system that was in trouble and transition. The new legislation and responsibilities put in place to remedy matters took time to bed down. Chapter 9 in vol. 14: Responsibilities for Human and Animal Health describes the main features of the system and the major changes introduced in the regulation of water and sewerage, waste tips, waste spreading and air quality. We had the impact of this situation very much in mind when we came to consider what was and was not done about BSE waste.
2. Markers about the importance of considering waste disposal
10.153 We were struck by the absence of any overt recognition in the proceedings of either the Southwood Working Party, the Tyrrell Committee or SEAC of the variety of pathways for disease that waste disposal might present. Individual aspects were considered from time to time. These were mainly concerns about contamination from identified items such as brain and spinal cord and with items causing public questions such as blood spreading on fields. None of these bodies seems to have thought it desirable to consider the possible infectivity of air particles from open burning.
10.154 One of the Tyrrell recommendations, however, had been to review whether there were 'hitherto unrecognised' pathways of transmission of BSE. The multiple forms of waste disposal certainly came within this category. We discuss in vol. 7: Medicines and Cosmetics the reasons why this comprehensive overview or 'audit' was not carried out. So far as pathways for waste were concerned there was initial information available within MAFF that could have been tapped, although the subject clearly ran much wider. In April 1990 Mr Lawrence asked the MAFF Meat Trade Adviser Mr Rogers to prepare a list of slaughterhouse products by way of providing a 'starting point' for embarking on the audit exercise. Mr Rogers commented at the end of his list, which focused on products with an economic value:
There may be a hazard from disposal of tankage material intercepted from the drainage system which in some cases years ago was disposed of with blood by spreading on land but should now be better controlled. Solids will probably go to be rendered and liquid treated in the effluent system.
10.155 This point does not seem to have been taken further. SEAC do not appear to have been aware of it, nor do they appear to have themselves raised concerns about the destinations of waste products. On the contrary, when they paid a site visit to inform themselves about slaughterhouse practices they were reassured to see that contaminating material on carcasses was being hosed off.
Relevance of existing experience in disposing of animal waste
10.156 MAFF already had well-established routines for disposing of carcasses from compulsory slaughter under the Animal Health Act. The special problems that arose in the case of BSE cases included the sheer scale of the epidemic and its widespread distribution across the UK. The shortage of incinerators to cope with soaring numbers of dead animals meant that carcasses often had to be transported long distances. It led to expedients such as open pyre burning that attracted considerable public criticism, but did have the merit of helping to deal with the problem at the time. We discuss this further below.
10.157 On the face of it there were also established routines for handling unfit meat, enforced by local authorities, that could conveniently be applied to disposing of SBO. Much unfit material removed from carcasses normally went under a movement permit system to be processed into a marketable product through 'sterilisation', in particular by rendering into tallow and MBM. Thus, much unfit meat was not waste in the sense of having no further use. If, however, the material was disposed of instead of processed, it became 'controlled' waste that had to be disposed of at a licensed site. The system was known to have weaknesses and be open to abuse by the unscrupulous, but was considered acceptable at the time.
10.158 We discuss in volumes 5 and 6 the extent to which the human and animal SBO bans achieved their respective objectives of keeping SBO out of the human and animal food chains. Even if these objectives were fully achieved, each of the handling processes for SBO generated at various points their own volume of waste material - solids, effluent and airborne particles - that might contain the BSE agent. Like other controlled wastes, they were discharged into rivers and sewers, emitted into the air or spread on land as fertiliser. These waste disposals were governed by the patchwork of arrangements that, as we have noted above, were attracting such heavy criticism. Moreover, after the introduction of the voluntary ban on SBO in animal feed, MBM and tallow made from SBO were increasingly treated as waste, ie, a product with no beneficial use.
10.159 We can see with hindsight that the impact of BSE on the emission of waste to land, air and water needed fresh thinking. As vol. 14: Responsibilities for Human and Animal Health explains, there were a number of controls on hazardous emissions but this regulatory system was not designed to deal with potentially lethal agents that were of minute size, undetectable by standard tests and of unknown degradability. The various pathways involved and what might be done about them needed special consideration and review. This was not to happen until March 1996 when the prospect of a massive cattle slaughter programme at last brought DOE and MAFF together to discuss 'the potential problems arising from the various disposal routes'. 1
How MAFF handled BSE carcasses and waste
10.160 We examined what matters were in fact considered. We also looked at the separate set of concerns that arose about the practice of spreading waste blood on fields. We set out below our views on the effectiveness of the action taken and conclude with some observations about the lessons this holds for the future.
1. Carcass disposal
10.161 When the compulsory slaughter scheme came into operation, MAFF sent out detailed instructions to their field staff about disposals. They favoured incineration at VICs or the CVL as the preferred option, then, 'in order of decreasing desirability':
10.162 Given the nature of the BSE agent this seemed to us the right set of priorities.
10.163 As the number of reported cases of BSE rocketed in 1989 and 1990, strenuous efforts were made by MAFF to get new incinerator capacity up and running as well as to seek other methods of disposal. They eventually got the disposals problem under control in 1992, as illustrated by the following table:
10.164 Although, looked at from this perspective, the numbers dealt with by burial were not large, they created considerable public disquiet. While disposal in the ground was less obviously offensive to the public than burning, there were concerns about leaching from buried carcasses into water supplies, whether from farms or from local authority waste tips.
10.165 Ministers queried the wisdom of burial, as did DOE officials. As we have seen, the view of officials in MAFF was that no risk was involved. We note that this was not seen as a matter that needed to be referred to SEAC and that a study on it was not carried out until 1997. This was as part of a comprehensive 'overview of the risks associated with BSE via environmental pathways' commissioned by the EA from outside consultants, in the light of the volume of carcasses to be disposed of under the OTMS scheme.
10.166 DOE officials also queried the apparent inconsistency of banning burial on local authority sites of raw SBO - derived from what were only potential carriers of the disease - while permitting whole carcasses of animals actually suffering from the disease to be buried on farm or in tips. MAFF had logical answers. The heads of such animals had been removed and burnt at VICs. Burial was under veterinary supervision, or on 'controlled waste' licensed tips. None the less the concerns remained, and as we have seen, burning in closed incinerators, with burial only as a last resort, was throughout the MAFF goal.
10.167 Could they have achieved this goal earlier? The weakness in the MAFF approach was their consistent underestimates of the likely course of the epidemic. Thus they successively planned on the following basis:
10.168 If the true numbers of cattle already infected had been appreciated, this might have affected some of the policy decisions taken. In the case of carcass disposal, the optimistic view of the likely future incidence of BSE meant that the extra incinerator provision they secured was repeatedly outstripped by demand. More realistic estimates might have provided a powerful trigger for a concerted plan to increase incinerator capacity more comprehensively or to establish how this might be done.
10.169 Those responsible for carcass disposal arrangements can not be blamed for proceeding on the estimates at the time which reflected the ignorance of the extent to which recycling of the disease had already taken place. In dealing with what became a Sisyphean task, the MAFF team showed commendable energy and persistence in seeking solutions.
10.170 We noted that, in the process of doing so, MAFF officials resisted DOE proposals - subsequently dropped - for a register of animal burial sites. On the face of it, this was a worthwhile proposal for protecting public health from dangerous waste. However, the purpose of the interdepartmental consultation had been to enable them to express any legitimate objections they had before a decision was taken by DOE. MAFF had real practical reasons for concern and raised these with DOE. It was entirely reasonable that they should have done so.
10.171 As regards open pyre burning, the volume was never high because of public objections, and much of it was on MOD land, well away from dwelling houses. The preferred strategy was to encourage private sector provision of closed burning. This too encountered problems. There was vigorous resistance to the grant of planning permission for incinerators, never a popular form of development among local residents. Some local authorities feared they might be left with a worrisome legacy of premises no longer needed to handle BSE carcasses. At the same time the proposed introduction of new, tighter regulations over incinerator standards threatened to reduce existing capacity for handling BSE cases and was resisted by MAFF, successfully, so far as smaller incinerators were concerned.
10.172 MAFF officials are not to be criticised for the energetic efforts they made to overcome reluctance to grant the necessary permissions for carcass disposals and new incinerators, nor for their lack of enthusiasm for new regulations and requirements that would make their task more difficult. In all these matters it seems to us that MAFF officials acted properly in laying their considerations and information in front of those responsible for decision.
10.173 These were reasonable responses in the light of the difficult and unpopular task they were having to carry out and the threat to public health if the disposal system were to break down.
2. Direct disposal of raw SBO
10.174 So far as unfit meat was concerned, it seems that this generally went off for rendering. Local Authorities were accustomed to operating a system of movement permits before unfit meat could leave the slaughterhouse or knacker's yard, and the limited exceptions under which unfit meat could, if in a container mainly of green offal (and in the case of carcass meat or specified offal, if stained) go to the renderers without a movement permit. They are not likely to have had experience of unfit meat going to waste tips.
10.175 The 1989 SBO regulations provided that unsterilised SBO could only be removed from a slaughterhouse under a movement permit. It would not need to be stained if it were going to excepted premises, ie:
- A hospital, medical or veterinary school, laboratory or similar institution for instructional or diagnostic purposes or the premises of a manufacturing chemist (in circumstances where he receives the offal for the manufacture by him of pharmaceutical products); or
- Premises used for the manufacture of products other than food and not used for the manufacture of food.
10.176 It seems that in practice, however, confusion arose among the many local authorities operating waste tips, with some permitting raw SBO to be dumped, while others refused permission.
10.177 We considered what had led to this confusion. There appeared to be several factors. First, there were the variety of LA practices under the Control of Pollution Act. Second, the new Inspectorate of Pollution had not yet got into its stride and appeared reluctant to offer advice. Third, as noted earlier in this volume, the local authority associations had been unable to give the draft SBO Regulations much consideration in 1989 because of the heavy involvement of their limited staff with the Environmental Protection and Food Safety Bills.
10.178 We consider that once the confusion was brought to their attention, MAFF were prompt in offering definitive advice through Mr Crawford's letter in June 1990. His advice was:
It is the clear intention of the Regulations that no raw, untreated offal to which these regulations apply should be taken to a landfill site for disposal except in an emergency. There are no such restrictions on sterilised offal.
3. Disposal after treatment
10.179 Up to 1991, as noted, SBO transformed into MBM and tallow could be disposed of either through the market, or on licensed tips like any other controlled waste, once rendered. In 1991 new secondary legislation was introduced. The final disposal of MBM from SBOs for the first time became controlled under a tighter regime than other unclassified controlled wastes. It could be sent only to premises approved under a MAFF licence. In practice, that meant an incinerator or licensed waste tip though some permits were granted for temporary storage in warehouses.
4. Wastes produced during separation and treatment of SBO
10.180 This was the aspect of waste disposal that received the least scrutiny in relation to the new problems posed by BSE. Only in 1996 did it begin to receive detailed consideration. 2
10.181 At the time that it was decided that SBO should not be permitted in human food, it was to be expected that in slaughterhouses, knacker's yards and other premises where cattle were killed, waste contaminated with SBO would be passing down drains as effluent, ending up in sewers or rivers. Slaughterhouse or rendering plant waste, or sewage sludge from works handling their effluents, might all lawfully be spread as fertiliser on land where animals subsequently grazed or crops were grown. This was seen as having a positive recycling and ecological value.
10.182 Following the voluntary ban on SBO in animal feed, the number of plants willing to render SBO into MBM and tallow steadily decreased. It could be expected that the raw material handled by these plants would include a significant amount of tissue which had come from cattle incubating BSE. Concerns surfaced in 1996 in terms of occupational risk from inhaled dust at the four plants dedicated to SBO rendering. The Advisory Committee on Dangerous Pathogens stated in April 1996 that they considered that TSEs 'including BSE, are not transmissable by aerosols or fine dust particles'. 3 This was a point of significance to those who later were concerned about dust emanating from vehicles transporting waste MBM and the buildings where it was stored.
What could have been done differently?
10.183 Although much of the evidence of the concerns raised over the BSE risk from effluent from Thruxted Mill relates to a time outside the period of this Inquiry, we thought these concerns and the action taken in response to them illustrated some of the difficulties that arise in dealing with secondary wastes. Appropriate tests and studies of BSE in effluent would have had application to all rendering plants and any desirable precautions could have been taken. Similar issues apply to slaughterhouses, head-boning plants and knacker's yards. Concerns over BSE risk from effluent could usefully have been considered, and perhaps resolved, much earlier for the benefit of all.
Who could have taken the lead?
10.184 We asked ourselves who might have taken this initiative. Prior to the establishment of the Environment Agency, the DOE was an obvious candidate. However, as noted above, MAFF did not inform them of the features of the BSE agent that might require a fresh look at the capability of the existing regulatory system to handle it.
10.185 We do not underestimate how difficult a task it would have been, involving so many agencies and with so many unknowns. The 1997 work shows what careful scrutiny is involved and the wide variety of interested parties. It was outside our remit to review how that was followed up. An examination of this sort, conducted earlier, could have considered whether, as a matter of practicality, because of the special characteristics of BSE, waste risk material should be dealt with at source as far as possible. This would probably have required new procedures. The fate of solid waste and effluent from certain processes such as head-splitting and brain-removal would have needed particularly careful consideration.
10.186 Dilution and degradation of harmful agents were both key features of minimising risks to public health and the environment. In the case of BSE questions arose as to the extent of dilution and degradation. Waste disposal authorities had a particular need to be well informed about ways of inactivating the agent and whether repeated exposure to small amounts might have a cumulative effect. They had a shared interest in research on these matters, both of which remain unresolved today.
10.187 At the beginning of this discussion we noted that no overview of risk from waste disposal practices appears to have been asked for or attempted by the Southwood Working Party, the Tyrrell Committee and SEAC. All of them, however, advocated a systematic review of the destination of all bovine materials. Had this been carried out, it might have been expected to identify many of the matters covered in this chapter and where more research or development of new techniques were needed. It would also have revealed the need for MAFF to carry out its risk management on a much wider canvas than its veterinary interests.
10.188 As it was, we saw little or no consideration of the issues BSE posed for the existing regime over waste disposal.
Spreading of blood and slaughterhouse waste
10.189 The only such area that received some sustained consideration by MAFF and led them to consult SEAC was the practice of spreading blood and other slaughterhouse waste on fields. Partly driven by media interest, this was the cause of some concern within MAFF and led them to question the existing guidance to farmers. However, as noted in vol. 11: Scientists after Southwood, SEAC did not consider that blood carried an infective risk when they reviewed it in 1991.
10.190 During the period to 20 March 1996 SEAC were not asked to consider the agricultural use of waste from rendering plants. This practice, which involved 'beneficial use' of the material in agriculture meant that it was not treated as controlled waste and was in effect subject to no control or regulation. This was a matter we did not have time to explore in our inquiry. However, prima facie, with an agent such as BSE, it would appear desirable to establish whether such material contains the BSE agent, whether its spreading poses any risk to animals or humans thereafter and to impose consistent controls.
Lessons from these aspects of BSE
10.191 These aspects of the BSE story demonstrate some lessons:
- We think the most important lesson for the future is that identification of pathways along which a transmissible agent might pass should always include waste. This might take many, not all immediately obvious, forms and require diligent tracing through a series of stages. This is likely to require a special exercise carried out on a much wider basis than the sphere of individual Departments.
- A problem in responding to BSE was the complex and disjointed swathe of arrangements covering land, water and air waste disposal and pollution. Even had a comprehensive overview identified the many waste pathways that needed to be considered, there would have been problems in developing an integrated policy approach. Matters have been improved through the creation of the Environment Agency. If this has not yet been done, it would be helpful to establish a clear lead role, similar to that exercised by the HSE on occupational risk, for the issue of consistent advice and guidance to those encountering new types of hazardous, or potentially hazardous, animal waste material.
- It might have been appropriate to consider into which category waste from potentially infective animal tissues might fall. There needs to be a clear mechanism for determining whether particular types of material should be allocated to the 'special' or 'hazardous' waste categories, thus triggering appropriate disposal arrangements. This applies also to cases where, as with BSE, the hazard is potential rather than proven. These are matters on which it would seem wise to clarify general principles and their application in advance of, rather than in the course of, any new threat.
- We found it difficult to distinguish between 'agricultural' and 'controlled' waste in respect of the risks posed by BSE. We were concerned that rendered material spread for agricultural purposes is not apparently a 'controlled waste', as it is in beneficial use, nor is it apparently covered by the provisions concerning rendered SBO material. Suspect tissues and processed materials need consistent consideration and criteria. Where subsequent action differs, it should be on the basis of reasoned analysis.
- We thought that the practice of spreading slaughterhouse and rendering waste on fields, while consistent with notions of recycling, none the less needs review. This would help ensure consistent precautionary procedures and guidance across the UK as a whole against the spread of animal disease or risk to humans.
- In the programme of BSE research, work on transmissibility through wastes was notable by its absence. Consistently, with what we have said above, the need for research on this aspect should be given careful consideration, both in relation to BSE and in the event of any future threat of this nature.
- Major changes have taken place in the structure of the waste recycling and disposal system as a result of BSE, in particular the virtual disappearance of knackers for handling fallen stock and the changed nature of the rendering industry. It would be desirable to review the efficacy of the arrangements today and the incentives they provide for the safe disposal of risk material.
- In considering ways to make the national system of animal disease surveillance and control more effective, as recommended in vol. 2: Science, new links between the notification status of disease and associated waste disposal procedures might usefully be explored.
1 YB96/3.27/3.2
2 YB96/3.27/13.9
3 SEAC 31/7 p. 4
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