HC Deb 05 April 1990 vol 170 cc1369-76

1 pm

Mr. Michael Latham (Rutland and Melton)

Rutland water in my constituency is the largest man-made lake in Europe. It is a reservoir which provides the water supply of 450,000 people. It provides recreation and enjoyment for many walkers, cyclists, horse riders, sailors, fishermen and wind surfers and is an internationally famous bird sanctuary and nature reserve. It provides employment and a living to several small businesses and is a major amenity for the east midlands as a whole.

On 7 September last, Anglian Water announced an immediate ban on sailing and warned people to keep away from the water's edge and especially to keep animals away. The reason for the ban was the weird blue-green algae which had been building up progressively on the surface of the water and at the water's edge over the previous few weeks.

I had only just returned from holiday that day, but the following morning, 8 September, I went to Rutland water with the district manager of Anglian Water, Mr. John Green. At that time fishing was continuing, but by the afternoon of that day it had been banned. A major competition scheduled for that weekend was cancelled. The closure remained in force until 18 October and resulted in great financial hardship for the small businesses and clubs which depend on the water. As far as I am aware, they have not been compensated in any way.

The closure of the reservoir was sparked off by the death of 23 lambs and at least 15 dogs. It is worth examining the chronology of the death of the lambs owned by my constituent, Mr. Renner, at Normanton Lodge farm. The first eight deaths occurred on 21 August. Mr. Renner collected a sample of algae which was then very visible and took it with two dead lambs to the Ministry of Agriculture, Fisheries and Food veterinary centre in Lincoln. All the lambs that died had blue-green algae on them. There were further deaths over the weekend of 26 to 28 August and on 4, 5 and 6 September.

The death of the dogs was also spread over several days. Some vets originally thought that they had eaten the rat poison warfarin because the horrible symptoms were similar to those which occur with such poisoning. There have been persistent local rumours since that that remains the cause. As recently as last month, a local councillor passed to me an allegation that someone had seen warfarin on the ground round the edge of the water. I have asked the water company about that allegation, but it was specifically denied in a telephone call to me last Friday by the managing director, Mr. John Simpson.

On 8 September, the day after the closure, the Leicester Mercury reported the affair. It quoted a spokeswoman for Anglian Water as saying that the public water supplies were not affected by the algae. She added: The treatment process deals with the blue-green algae. It will have no effect on the drinking water. The same day, the newspaper quoted Dr. Garry Whitelam of the university of Leicester saying that several forms of the algae were toxic, that it was a worldwide problem, and that there were three different kinds of cyanobacteria, one of them a liver toxin which had caused catle deaths in other countries, another a neurotoxin which had caused convulsions and spasms in mammals and another a skin irritant known as swimmer's itch. If that was known to Dr. Whitelam, it should presumably have been known to Anglian Water.

On the day I visited the reservoir, I was specifically assured by Anglian Water that there was no danger to public water supplies and that the algae had been caused by the long dry spell of weather. I was told that it was an entirely natural phenomenon resulting from nutrients in the rivers which were pumped into the reservoir interacting with the sun.

However, I was not fully satisfied by those explanations, and directly after the weekend I wrote to Lord Crickhowell, the chairman of the National Rivers Authority, asking him to undertake an investigation. I also spoke on the telephone to his chief executive, Dr. John Bowman. I questioned Dr. Bowman closely about whether the problem had been made worse by discharges of phosphates into the rivers Welland and Nene or by the sewage being discharged from Okeham sewage works. He confirmed that discharges of that kind would certainly add to the process of eutrophication and thereby to the nutrient content of the water.

Since then I have been in continual correspondence with the chairman of Anglian Water, Mr. Bernard Henderson, with Lord Crickhowell of the NRA and with Ministers. I have been to see two Ministers, my right hon. and learned Friend the Member for Folkestone and Hythe (Mr. Howard), and my hon. Friend the Member for Rossendale and Darwen (Mr. Trippier). I made a brief speech in the House on 13 November and I have asked numerous oral and written questions. However, I am still completely dissatisfied with the co-ordination and scope of the investigations.

When I went to see my right hon. and learned Friend the Member for Folkestone and Hythe, I felt great unease about the co-ordination between the NRA, which did not know the result of the post mortems on the sheep or the dogs, the Ministry of Agriculture, Fisheries and Food, which had not supplied information from its veterinary service to the Department of the Environment, and the Department of the Environment itself, which did not seem to know much at all, even about the important researches of Professor Geoffrey Codd at Dundee university.

However, a number of facts have emerged. First, the post mortem on Mr. Renner's lambs carried out by the Ministry of Agriculture, Fisheries and Food's veterinary service confirmed that microcystin toxin has been found in the liver and rumen contents.

Secondly, a substantial amount of scientific materials about algal poisoning is available in learned journals, mostly in the United States. For example, a note on algal toxins in Wisconsin waters experiencing blue-green algal blooms, written by three water scientists, appears in the 1988 edition of Lake and Reservoir Management. That is all on public deposit in the United States and it is widely available. The 1976 edition of "Black's", the standard veterinary dictionary in Britain also has an article on algal poisoning and is available in the library of MAFF's veterinary service with which MAFF vets are familiar, as the Parliamentary Secretary to the Ministry of Agriculture, Fisheries and Food admitted to me on 24 January in a parliamentary answer. The recent learned paper by Professor Codd has five pages of references to other works on the subject.

Thirdly, I have not seen any post mortems on the dogs, but the Parliamentary Secretary told me on 11 January that two dead dogs had been examined by MAFF vets and that their deaths may have been linked to the ingestion of blue-green algal toxins.

Fourthly, the NRA, which is conducting an investigation which I hope will be published shortly, has confirmed that the principal species associated with the toxic blooms on Rutland water was microcystis acruginosa, which produces the toxin microcystin.

In the past few days, Anglian Water has sent me two reports which I intend to treat as public and which I understand have been given to the Department of the Environment and to Rutland district council. One of them hums and hahs at considerable length about the causes of the disaster last August and September and refers to the work of Professor Codd at Dundee university. It admits that the first report about the scum from toxic blooms was published as long ago as 1878, following the death of domestic animals. It says that none of the post mortems on the animals that died at Rutland water is conclusive, but it admits: the symptoms described are consistent with microcystin poisoning. It accepts that phosphate and nitrate are key nutrients and that phosphate concentrations rose slightly in Rutland water in 1989 because of increased pumping from the Rivers Welland and Nene during a dry summer.

The report suggests that there must have been special factors at Rutland water to account for the heavier scum than at other reservoirs, which it blames on local physical features such as the prevailing winds or water movements. It adds that additional biologists and biological technicians are being recruited and that extra treatment is being installed at Oakham sewage treatment works to remove the minor load of phosphate. However, the report admits: it is therefore possible that given similar climatic conditions, blue-green algal blooms could develop during the interim, including the coming summer.

There follow three extraordinary sentences: It seems likely from the evidence that healthy fish caught at the time of a microcystin bloom are probably safe to eat. However, if an angler has any doubts, it is open to him or her not to eat the fish. If more specific advice can be given at the time of an incident such advice will be made available. Not many people will regard those statements as helpful or reassuring.

Anglian Water's second report concerns water supply. It is worth remembering that, at every stage, Anglian Water said that the drinking water was safe. The report is hard to understand and is full of endless qualifications about the difficulty of comprehending data and whether the scientific results are satisfactory. According to the report, there was a brief period, from mid-October to 1 November 1989, when some possible microcystin in the filtered, final water was measured at up to 16 mg per litre on one particular day, compared with less than 1 mg in late September 1989.

The scientists seem unsure whether their experiments are valid, whether the element really was microcystin or what they call pseudo-microcystin, or why some of the treated water had a higher concentration of it than the untreated water. Clearly, the experts are very sceptical about the findings. They say that there remains a strong possibility that the compound reported as microcystin was wrongly identified, and report that work is continuing. They conclude that the water did not contain—this is the vital point—microcystin at levels harmful to health. They make proposals, including the use of granular activated carbon, for an additional form of treatment if another major problem arises in the future.

There is no need to be alarmist about those vague, confusing and possibly incorrect findings, but my constituents and I are entitled to a specific answer—yes or no—from my hon. Friend the Minister to two simple questions. First, was the treated water at all times absolutely safe to drink last autumn, as the Anglian Water spokesman said publicly on several occasions? Secondly, has the water been absolutely safe to drink at all times since, including now? I hope that my hon. Friend the Minister will answer unequivocally yes to both questions. If he cannot do so, the chairman of Anglian Water should resign immediately.

The very fact that I have to ask such questions shows how unsatisfactory the whole affair has been. It has revealed indecisiveness, defensiveness and inadequate research and action by Anglian Water. The Department of the Environment and the Ministry of Agriculture, Fisheries and Food have shown nothing like enough energy or determination in getting to the bottom of this disgraceful affair.

The Government have a duty to take action in five respects. First, they should establish an independent public inquiry under a High Court judge to determine whether that environmental disaster could have been prevented, its causes, whether the company was negligent or blame worthy. That inquiry should begin as soon as possible and report by the autumn. Last summer, 38 animals died—supposing a child had fallen out of a boat?

Secondly, the Minister should offer the full resources of Government scientific knowledge and advice, and if necessary fund additional research facilities at Dundee university or elsewhere. Department and NRA scientists should be sent at once to the United States to discuss findings with their American colleagues, who have great expertise in the subject.

Thirdly, the National Rivers Authority should be instructed to produce its own reports by the end of this month at the latest with specific recommendations.

Fourthly, the Minister should demand a full checklist for action from Anglian Water as to how it intends to prevent a repetition of the disaster this coming summer.

Finally, Anglian Water should immediately pay ex gratia compensation to all those people who lost animals and to business men who lost money because of the closure. If the commission of inquiry which I suggested finds Anglian Water blameworthy, the ex gratia sums could be augmented by the courts.

I hope that it will be clear to my hon. Friend the Under-Secretary that I have a deep sense of frustration and anger about this affair. Before I leave the House at the next general election, I intend to ensure that the matter has finally been settled and that public concern is fully allayed. I look to my hon. Friend for a full response today.

1.16 pm
The Parliamentary Under-Secretary of State for the Environment (Mr. David Heathcoat-Amory)

I congratulate my hon. Friend the Member for Rutland and Melton (Mr. Latham) on securing this debate and on pursuing this issue with his characteristic persistence and vigour. I fully understand his desire to protect his constituents and to try to get to the bottom of this complex issue. I hope during my remarks to answer the points that he put to me.

It might be helpful to the House if I first say a few words about the nature of the algae of concern here, and recap on the events of last year.

As my hon. Friend knows, algae are minute aquatic plants which grow naturally in all surface waters. Their growth is determined by combinations of environmental factors such as sunlight, the length of day, temperature, nutrients and so on. With the constantly changing conditions in a lake, a succession of different species will thrive. There are more than 1,000 species of such algae in Britain. Towards autumn, the species which often dominate are of the blue-green type which is the subject of today's debate.

Although this succession rarely causes problems, under some conditions a so-called "bloom" of algae will occur. That is what happened at Rutland and in some other lakes last summer. Most algae are completely innocuous and are necessary for the life of the lake, but a few individual species of blue-green algae produce a toxic substance which can be released to the water. Microcystis is one of those algae and the toxin microcystin is sometimes, although not always, produced. We do not yet know of the mechanism by which this toxin is produced, nor the conditions favourable for its production.

Last year's problems of blue-green algae became apparent when reports were received in September of a small number of deaths in dogs and sheep following contact with Rutland water in my hon. Friend's constituency. Before 1989, we were not aware of any recorded incidents of adverse effects within the Anglian region.

Anglian Water's account of events shows that its biological monitoring of Rutland water in July and early August showed relatively low algal numbers in the main body of the reservoir. But following the reports of those animal deaths at the end of August and in September, Anglian Water carried out further sampling of algal scum, which was identified mainly as the blue-green algae microcystis. It then sought advice from Professor Codd at Dundee university on its toxicity.

By 7 September, Anglian had decided that there was sufficient circumstantial evidence available to show that the scum was toxic and could be hazardous. It therefore closed the reservoir to recreational activities and sought advice from veterinary specialists on the cause of the animal deaths.

For its part, the National Rivers Authority responded quickly. The Authority carried out extensive sampling of some 750 reservoirs and similar waters in England and Wales, to test for the presence of toxic blue-green algae; 53 of them in England were found to contain algae of toxic forms.

Secondly, having identified the areas at risk, the NRA suggested to site owners that they should consider taking a number of precautions, which they did. Apart from advising site owners on the action to take, the NRA of course informed local environmental health officers of its findings and advice. Finally, the NRA instituted a detailed analysis and review of last year's events.

As for the public health effects, Anglian Water concluded, on the basis of the evidence available that there was no hazard to public health from drinking water supplied from the two treatment works fed by Rutland water. Our medical advisers are unable to give definitive advice because of the unreliability of the analytical information available and the absence of any reliable toxicological data for algal toxins. They agree, however, that water from Rutland put into supply for drinking after treatment is extremely unlikely to pose a threat to health. No adverse human health effects have subsequently been reported as arising from Rutland water's problems.

The algae were concentrated at the shallow margins of the reservoir. Water for treatment is drawn from 15m deep in the main body of the reservoir, where algal concentrations were relatively low. Furthermore, the comprehensive water treatment facilities, which include the use of granular activated carbon filtration at the two Rutland treatment works, are likely to have removed any algal toxins which may have been present in the raw water.

My hon. Friend has drawn attention to the report just issued by Anglian Water Services Ltd. which sets out its views and analysis of last year's problems and what needs to be done in the future. A number of Anglian's comments will be echoed in my remarks today. One of the report's main conclusions is that more data are required to produce a reliable determination of the longer-term significance of algal blooms and the production of toxins.

The detection of microcystin in water is a complex analytical process all of its own. That is why conclusions and recommendations must be qualified and must not go ahead of the available scientific evidence. Anglian Water Services Ltd. also concluded that, so far, post mortems have proved inconclusive, although circumstantial evidence strongly suggests that algal toxins were the cause of death of the animals concerned.

The report also concluded that no significant increases in nutrients occurred last year, so it suggests that climatic conditions were the major contributory factor for algal growth.

On the available evidence, the report concludes that drinking water did not contain toxin at levels which cause harm to health, although it draws attention to difficulties in interpreting uncertain analytical information about the presence of microcystin in drinking water.

Finally, the report set out Anglian Water's future proposals, which include an improved monitoring programme, investment to reduce the levels of phosphate inputs into Rutland water, greater use of granular activated carbon treatment for drinking water and suitable arrangements for warning local people of the risks if algal blooms recur. This report is both constructive and helpful.

It was against that background that the National Rivers Authority set up a task group last year to investigate the blue-green algae problem. The terms of reference of the group are very wide. They are to assess the problems that occurred last year at Rutland water and elsewhere; to assess the extent of the problem, not just in the United Kingdom but abroad; to review the influence of nutrients; to review the influence of water quality management techniques; to review the influence of biotic factors; to identify the research and development requirements; to assess the staff resource implications; and to make recommendations for monitoring and eutrophication control to minimise the problem in future. The task group is being chaired by Mr. Pearson of the NRA's Anglian region. It also includes Professor G. A. Codd of the university of Dundee, a leading expert in blue-green algae, Dr. Reynolds of the Institute of Freshwater Ecology and Mr. Fawell of the Water Research Centre, who is a toxicologist. My hon. Friend will agree that it is a wide-ranging inquiry conducted by experts.

The group intends to produce its report by early summer, but I cannot accede to my hon. Friend's request that it should be accelerated and produced by the end of the month. It will be produced before the main season for the development of blue-green algae. The group has contacted all NRA regions, water plcs and water companies that operate lakes and reservoirs.

In addition, since similar problems have been reported in a number of other countries, information is being collected from sources overseas and, as part of the NRA's research effort, the WRC is carrying out a full literature search and review.

I hope that that meets the point made specifically by my hon. Friend. I promise him that the group will aim to collate and review the problems and recommend future action to be taken. Research needs have to be indentified and budgeted within the NRA's programme to investigate the problem and produce effective systems for monitoring and control.

My hon. Friend will understand from my earlier remarks that it is simply not possible to prevent the growth of algae, as they are a naturally occurring phenomenon. Nevertheless, the task group considers that it is possible to take preventive action to reduce risk. It is therefore preparing a scheme to identify those lakes with the potential for problems. The group is devising a sampling programme which will categorise lakes used for public supply and immersion sports according to the risk of algal blooms occurring. A proportion of high-risk lakes will be subject to routine sampling and, by applying criteria for phosphate levels and algal content, it will be possible to inform owners when it would be advisable to take stock of the situation in the waters under their control and to make plans to minimise the risks.

As I have said, there is no record of damage to health via drinking water, despite the widespread occurrence of algal blooms. Nevertheless, I consider that there is an urgent need to improve our knowledge of the toxic effects of microcystin and to develop a reliable methodology for the detection and analysis of the toxin. Research is currently being carried out by Professor Codd for the water industry to develop improved analytical techniques for microcystin. We shall build upon his work to investigate the potential risks to consumers' health from the occurrence of algal toxins in drinking water.

These are vital steps in broadening our knowledge of the subject which, together with the work that the NRA is already undertaking, will provide a valuable base from which to consider the development of standards for algal toxins in drinking water.

I recognise my hon. Friend's concern about the issue. I entirely agree that we need to obtain the best possible picture of what took place last year. However, it is a complex matter. We must rely on good science to produce the answers. We must not rush ahead with hasty conclusions that are not supported by research. We are determined to get to the bottom of what occurred and, perhaps more importantly, what can be done if the problem recurs. In the light of that, and the fact that the NRA investigation already under way, I am satisfied that all possible steps are being taken to inquire into that unfortunate and tragic incident in my hon. Friend's constituency, and that the necessary follow-up action is in hand.

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