HC Deb 17 February 1978 vol 944 cc964-78

Motion made, and Question proposed. That this House do now adjourn.—[Mr. Stallard.]

4.12 p.m.

Sir Bernard Braine (Essex, South-East)

Some 33,000 of my constituents live on Canvey Island, alongside one of the largest and most dangerous concentrations of gas, chemical and oil storage in the country. As though this is not enough, successive Governments have given planning permission to introduce oil refineries to this endangered environment in the teeth of opposition from the local community and often against the advice of their own inspectors. In doing so they have recklessly compounded the existing risks.

As the House knows, this situation has been the subject of repeated protests by me, by the local authority and by my constituents. By 1975 even the Government were beginning to understand that the protests should be taken seriously. After an exploratory inquiry, which came down firmly on our side against one of the proposed refineries, the new Health and Safety Executive was directed to conduct the first-ever investigation into the totality of risk facing an entire community.

This certainly seemed a victory for common sense. My constituents were invited by the hazards team to set out their views as to the risks, and a large number responded. The Canvey Island Conservative Association, for example, set out no less than 10 possible interactions between the proposed and existing high-risk installations which they wished the team to investigate.

Among their queries were several relating to the safety of the British Gas Corporation's methane terminal. This consisted then, as now, of four huge underground pits, each capable of holding about 20,000 tons of liquefied gas, and six above-ground tanks, with a total capacity of 108,000 tons.

The walls of the underground pits are frozen by refrigeration. No lining is needed, because the liquid gas pumped is at minus 160 degrees Centigrade, and the surrounding earth stays frozen as long as there is liquid in the pit. A lid is put over the top. It all sounds very simple, but as the cold spreads to the surrounding soil it cracks and lifts it, and the fissures are filled with methane vapour, which in turn freezes, expands and continues to crack the soil, so that we have a phenomenon known as frost heave. The theory is that within a reasonable distance equilibrium is restored. There is a side consequence, in that special steps have to be taken to ensure the stability of the overhead gas pipe system, which would otherwise fracture.

One would breathe a little more freely if an installation of this kind were far removed from the built-up area. But it is not. It is close to the homes of thousands of my constituents. Ironically, the Health and Safety Executive recently asked the Castle Point District Council to notify all new planning permissions within a radius of 2 km of this installation. A prudent requirement, one might think, but within a radius of 2 km. there are already 8,600 dwellings and 23,600 people. It is very late in the day to ask such questions of the local authority—and what, one may ask, about the people who are already forced to live with these uncertainties and risks next door to them?

There is certainly one question which should be asked right now. Of the dozen similar pit storage plants built around the world, 10 had been abandoned by 1975 as inefficient. Apart from Canvey, the only other one in commission at that time was in Algeria, at the beginning of the liquefied natural gas supply chain from the Sahara Desert to Canvey Island. Conch Methane, the firm which invented this method of gas storage, abandoned it soon after the plant at Canvey Island was commissioned. When asked the reason in 1975, the company's head of engineering and design frankly admitted: We don't know enough about the mechanical behaviour of frozen soil around unlined pits to predict results and control insulation within economic limits. For a time it seemed that the British Gas Corporation realised that it had made a mistake, and in a letter to me dated 11th February 1975 the corporation stated categorically: the four underground liquefied natural gas storage tanks … are to be taken out of service at a date to be decided. In this country there is a shortage of LNG storage to meet the peak winter demand and therefore we still require these tanks to meet that demand. Our construction programme envisages erecting above ground tanks in the South of England"— they did not say where— and when these are complete it should be possible to discontinue the use of the underground storage at Canvey. That was three years ago, and it was cheering news. But what happened to the construction programme? Why are these manifestly unsatisfactory tanks still in use at Canvey, despite the evidence that their instability is increasing?

I have never ceased to be uneasy about the matter, so I though it only right to ask the chairman of the British Gas Corporation some searching questions. I wrote to him on 16th November last. I asked what were the corporation's plans for the future in regard to the storage of liquefied gas on Canvey when the Algerian contract ran out in 1980. I asked whether it was intended to liquefy North Sea gas at Canvey and to store it there. I asked whether there were any difficulties in decommissioning the underground tanks. And I asked about safety.

To my astonishment, I was told in reply that the corporation, contrary to everything that I had been told three years before, intended to continue the use of underground storage at Canvey beyond 1980 even if the Algerian contract was not renewed. If it was considered desirable to end this method of storage in 1975—and I have shown that this was the case—what has happened since to change that view?

As for any decommissioning of the underground pits, I was told that there were no technical difficulties about that which could not be overcome by careful planning and preparation, that similar tanks had been successfully decommissioned in the United States, and that research was being undertaken into the decommissioning procedure. Am I to assume from that answer that the pits could be decommissioned safely in the next few months if that was considered necessary? Frankly, from my information, I very much doubt it.

I must tell the Minister that I had taken the precaution of checking my questions in advance with the Health and Safety Executive. The Executive assured me that they were "perfectly sensible" questions to ask, and that they should be asked. At the same time, however, I was told that the report of the hazards team looking into the totality of risks facing my constituents was not likely to go into any great detail regarding the questions that I was putting, simply because we will not have been able to go into that amount of detail about every installation in the area. If, therefore, you would want to get this detailed information it would be best for you to write direct to the Gas Corporation. That was an astonishing statement to come from the organisation which is charged under the Health and Safety at Work, etc. Act to monitor the safety of industrial establishments.

When I did receive the answers from the British Gas Corporation, I was told that these were not unreasonable and did not point to any immediate follow-up operation. As to whether I could accept the answers without further question, I was told that a categorical assurance on these lines could not be given unless there was a detailed investigation and that this would not be justified at this junction, given the current study of the hazards team. However, I could be assured that from now on the Health and Safety Executive will be checking on the content of these replies as part of its normal enforcement activities.

As can be imagined, my reply was short and to the point. If the hazards team has not been able to go into details about every installation in the area, what has it been covering? There are only three high fire risk installations on Canvey. The methane terminal is the most important, and in many ways the most dangerous.

A further consideration that I would put to the Minister is that we should never consider the situation at the methane terminal in a vacuum. When I speak of hazards at Canvey I am referring not only to the problems of storing hazardous materials. Liquid methane gas is arriving from Algeria—12,000 tons of it at a time—at weekly intervals. Other tankers laden with petroleum products and chemicals. low-flash cargoes, are putting in at neighbouring jetties. Oil and gas are piped in, parallel with the sea wall, to join the main United Kingdom pipelines. Road tankers carrying inflammable products are leaving the installations and joining normal traffic on our roads.

In short, my constituents are enmeshed in a huge web of static and mobile risks. Not a month passes without some incident—a collision in the river, a spillage or a fire. Last month alone a vessel collided with the Texaco tanker jetty spilling 30 tons of motor spirit into the river. The fire brigade, police, Thames Navigation Service and the Port of London Authority were all alerted, and fortunately the danger passed.

On 11th January the LNG carrier "Aries" berthed at the methane terminal jetty and in storm force winds broke away from her moorings. The traffic on the river had to be stopped. Fortunately again, there was no collision and no explosion. But incidents of this kind are happening far too often.

That was the background to the two Questions that I put down for answer to the Secretary of State on 1st February. The first asked him to direct the Health and Safety Executive to undertake a detailed inquiry into the safety of frozen methane storage at Canvey. The second asked what research the Executive had undertaken regarding the problems of such storage, what were the implications for the adjoining residential area, and why the report of the hazards team on the totality of risks at Canvey—which had been commissioned by the Secretary of State nearly two years ago—continued to be delayed.

The Under-Secretary of State chose to answer the two Questions together. With great respect, I think that in doing so he blurred the issues. He said that since the methane terminal was one of the installations currently under investigation by the hazards team there was no need for a separate inquiry.

Here I feel that the hon. Gentleman was badly briefed. It is clear from the correspondence I have received, as I think have shown, that the Health and Safety Executive did not go into the matter in the kind of detail that my Questions suggested was necessary and the kind of detail that my worried constituents are entitled to expect. The Under-Secretary of State said, however, that the investigation would undertake—he did not say that it had already covered—an assessment of the risks to the adjoining residential areas. He has thus thrown into serious doubt the worth of the investigation to date.

The only conclusion that one can draw is that if the investigation is to be thorough there will have to be further delays in completing and publishing the report. But what was the purpose of that report in the first place? It was to enable the Secretary of State for the Environment to make up his mind whether to accept his own inspector's recommendation three years ago to revoke planning permission for one of two oil refineries. We in South-East Essex are sick and tired of waiting for Ministers to make up their minds on our safety.

I must, therefore, ask the following questions, which, since they are concerned with safety, cannot wait for the publication of a report which was promised last year but which is postponed month after month. First, is it true, as the Press has reported, that the area of frozen ground around the underground pits at the methane terminal is spreading? If so, how fast is it spreading? How near is it getting to the sea wall, to the aboveground tanks and to the nearby residen- tial area? Are there dangers if frost heave ruptures the above-ground tanks, as I am told it could?

Secondly, what is the purpose of the giant radiators that are being used to warm up the site?

Thirdly, where does the truth lie in regard to the underground pits being operated at only half capacity? Is this due to commercial reasons, as the Health and Safety Executive tries to tell me, or was the spokesman of British Gas quoted in the Evening Echo of 27th January very much nearer the truth when he was reported to have said: We have only operated at about half capacity because if we filled them up … the frost would spread quicker"? That, of course, touches upon safety. Whom, then, are we to believe?

Fourthly, is it correct that the aboveground tanks do not conform to the most modern standards which would require them to be protected by high dykes? If so, why are lower standards permissible on Canvey close to residential population?

Fifthly, is it a fact that no liquefied gas storage is permitted anywhere else in Britain close to so large a population? If so, why is British Gas being allowed to go on using this unsatisfactory method well into the 1980s?

Sixthly, can it be confirmed that the whole installation is at the moment at a complete standstill due to an industrial dispute? In other words, has the whole installation been shut down, and, if so, what special safety precautions are being taken in view of the situation that I have described?

Clearly this is an unsatisfactory, uncertain and worrying situation. In my view, it demands a separate, independent, scientific and thorough investigation of the methane terminal on its own. It demands a clear public statement by the British Gas Corporation about its intentions in the years ahead. Finally, it demands that there shall be no more excuses for delaying a decision about other risks—namely, the oil refineries. Ministers should act now. The safety and peace of mind of my constituents demand nothing less.

4.27 p.m.

The Under-Secretary of State for Employment (Mr. John Grant)

I can fully understand and sympathise with the concern felt by the hon. Member for Essex, South-East (Sir B. Braine) on behalf of his constituents who live near the British Gas methane terminal on Canvey Island and, indeed, who live with the concentration of gas, oil and chemical storage which he has described graphically and which undoubtedly presents unique features. The hon. Gentleman's concern is shared not only by me but also by the Health and Safety Commission, which is giving the matter considerable attention.

I shall try to deal with as many of the matters raised by the hon. Gentleman as I can. However, time will not permit me to deal with all of them. I refer first to what he said about the industrial dispute, because I think that I can dispense with that straight away.

There is an unofficial dispute in progress which has currently shut down the installation. It involves 48 workers out of a total labour force of 167 and concerns shift work differentials in relation to other installations. It has nothing to do with safety questions. All safety equipment is fully manned by five safety personnel and by British Gas people, and I can assure the hon. Gentleman that there is full maintenance coverage, so that there should be no problem on that account.

I deal now with the installation at the methane terminal which is used primarily for the importation and storage of liquefied natural gas from Algeria. It is also used for the storage of liquefied butane and, from time to time, new ships designed to carry liquefied natural gas are commissioned there. About 50 shipments of gas from Algeria are brought to the jetty at the terminal each year using two specially designed ships each with a cargo capacity of about 12,000 tonnes.

The fully refrigerated liquid gas is pumped ashore from the gas carriers and piped directly to a number of aboveground and in-ground storage tanks having a total capacity of approximately 100,000 tonnes, where it is held until it is needed. Before it is sent by pipeline into the national gas grid, the LNG is presurised and evaporated to gas using sea water as the source of heat. The current demand on the terminal varies between 100 million and 200 million cubic feet of gas per day.

As regards the extent of in-ground storage of LNG, I am not sure that I can agree with the hon. Gentleman's arithmetic. I understand there have been five such installations altogether, including the one on Canvey Island. Two in the United States have been closed for economic reasons, but similar installations involving large quantities of gas are still operating in Japan and Algeria.

I turn now to the question of hazard. Methane is a flammable gas when mixed with the right amount of air. A release of the gas will, if an ignition source is available, catch fire and burn, and an explosion can occur in certain circumstances.

There are eight above-ground storage tanks, six of 4,000 tonnes capacity each and two of 1,000 tonnes capacity. The tanks are double-walled. The inner wall is of aluminium alloy and the outer of steel. Each tank is surrounded by a clay wall 7 feet in height, and I am told by the Health and Safety Executive that it fully satisfies the current safety standards, and that there should be no reason for anxiety on that ground.

For in-ground storage, there are four storage pits, each 130 ft. in diameter and 130 ft. deep, giving a total capacity of about 20,000 tonnes of LNG per tank. They were formed by digging out a large hole in the ground, are unlined, and rely on frozen earth to contain the liquid gas. Each tank is spanned by an aluminium roof mounted on a ring of reinforced concrete.

When the tanks were commissioned, it was expected that the thickness of the ice wall—initially 30 ft.—would grow substantially, due to the very low temperature of the LNG, but that this would stabilise at a thickness of about 100 ft. In practice, the thickness has continued to increase and has now reached 120–130 ft., with an annual rate of progression of about 6 ft. This continued growth is thought to be linked with an unexpected amount of fissuring of the frozen ground, which also accounts for the fact that the rate of uptake of heat into the LNG has been substantially higher than expected, and that there has been some limited gas leakage to atmosphere from the ground around the tanks.

There has been much comment recently in the Press about the safety implications of the growth of the ice wall around the in-ground storage pits. The ice walls are in fact still several hundred feet away from the nearest point of the sea defences, and the method of suspending overhead pipes in the area allows for adjustments to ensure their safety. A heat barrier—the giant radiator as it has been called—consisting of hot water tubes, was installed at the side of the pits nearest to the above-ground storage tanks in August 1977.

This barrier has effectively halted the growth of the ice wall on that side of the pits. The heat barrier is working precisely as intended, and British Gas is able to adjust the temperature of the barrier so as to maintain the ice wall in its present position on that side of the pits and to prevent its further growth.

The heat barrier was installed by British Gas, on its own initiative, so as to halt the growth of the ice wall long before it could possibly reach the area of the above-ground storage tanks. I am assured that if the Health and Safety Executive considered that the continued growth of any part of the ice wall was likely to lead to danger on Canvey Island, it would require British Gas to take appropriate action, assuming that the Corporation had not itself already taken such action, as it has done.

The level of LNG in the storage pits has been progressively reduced since the pits were commissioned in the late 1960s. This has been done because the "boil-off" rate of the gas has been greater than was anticipated, and it would be uneconomic to keep the LNG in the pits at too high a level. The current average depth of LNG in the pits is 45–50 ft.

I should perhaps explain that "boil-off" is not a release of gas to atmosphere, but a revapourisation of LNG above minus 162 degrees Centigrade which is piped from the pits to a gas holder, from where it is usually reliquefied and put back into storage. Some Press reports have suggested that the pits are kept half full in order to prevent too rapid a growth of the ice wall. British Gas has assured the Health and Safety Executive that this is not the case, and has reiterated its previous statements to the Executive that the tanks are kept less than half full for commercial rather than safety reasons.

Sir Bernard Braine

A great deal of what the hon. Gentleman is saying completely confirms what I have always told the House, but what I am anxious to find out is why, if in 1975 the British Gas Corporation wanted to decommission these tanks and run the plant down for commercial or any other reason, it now takes a totally different view. Is the hon. Gentleman going to deal with the point about the future?

Mr. Grant

I am coming to that point; the practice that I have described does, of course, reduce the rate of growth of the ice wall, but that is not the reason for it. The Health and Safety Executive does not consider it necessary to limit the amount of LNG in the storage pits. It has at no time asked and does not intend to require British Gas to maintain the tanks half full for safety reasons.

On statutory controls, the methane terminal is the subject of a licence issued by Essex County Council under the Petroleum (Consolidation) Act 1928 which was applied to liquid methane by the Petroleum (Liquid Methane) Order 1957. The licence lays down detailed conditions governing the operation of the terminal and the safety precautions to be taken. Officials of the county council visit the terminal frequently to ensure that the terms of the licence are being compiled with.

Operations at the terminal are also subject to the Health and Safety at Work etc. Act 1974. This means that the British Gas Corporation must ensure, so far as is reasonably practicable, the health, safety and welfare at work of all its employees and conduct the terminal in such a way as to ensure that members of the public are not thereby exposed to risks to their health and safety.

I understand from the Chairman of the Health and Safety Commission that the Health and Safety Executive is satisfied with present standards of safety at the installation.

The methane terminal is one of a number of installations handling hazardous materials both on Canvey Island and the nearby part of Thurrock Borough Council. All these installations are currently the subject of an investigation being conducted by the Health and Sefety Executive into the overall risks to health and safety arising from the activities both at the existing installations and those which are proposed within the scheduled area of the investigation.

I am advised by the Chairman of the Health and Safety Commission, who agreed to undertake this investigation at the joint request of my right hon. Friends the Secretaries of State for Employment and the Environment that he expects to receive the report in the spring of this year. I cannot be more specific than that, but I take it that spring will not be a little late this year.

The British Gas terminal is within the scheduled area of the inquiry and I understand that an investigation of all aspects of activities at the terminal, including the storage arrangements and the implications for nearby residents, has been carried out as part of the inquiry. I cannot, of course, anticipate what the report will say, but if it points to the need for action, I do not doubt that the Health and Safety Executive will be ready to take whatever action seems necessary.

On the point about the time taken for investigation, the investigation is unique and is the first of its kind to be undertaken in the United Kingdom and probably in the world. It began in April 1976 and has involved a number of specialists in very painstaking inquiries and assessments. It has been a far more complex exercise than was anticipated when it was started, but I understand that the necessary field work has now been completed and the report of the investigation team is at an advanced stage of preparation. I am assured that top priority is being given to the completion of the report.

I trust that, in view of that assurance, the hon. Member will see that it will not be long before a decision is possible on the revocation of planning permission for the United Refineries oil refineries.

I understand that the hon. Member has been in correspondence with the Health and Safety Executive raising a number of very detailed points concerning various aspects of the operation of the gas terminal. Some of these are strictly outside the precise terms of reference of the investigation, although they may well be matters which will require further consideration in the light of the investigating team's assessment of risk.

I cannot accept that the parliamentary answers blurred the issue. There appears to have been a genuine misunderstanding here about the depth of the investigation into the assessment of risk. I am assured that the investigation has been very thorough and detailed at all the major installations within the scheduled area of the investigation. One must remember however, that if the report of this complex investigation is to be kept to a reasonable size then it cannot possibly record in minute detail every aspect looked at by the investigating team.

If the hon. Member still feels, when the report is available the need for further information on any matters connected with this investigation, I shall he happy to arrange for him to discuss this with the investigating team. If this still does not give him all the answers he requires he will no doubt get in touch with me.

Sir Bernard Braine

Is there anywhere else in the kingdom where such a concentration of storage of this kind is so close to residential population? The plain fact of the matter is that if a planning permission of this kind were sought today, it would not be granted and the Minister knows it. It is extremely important that the intentions of the British Gas Corporation should be made known. In 1975 they wanted to abandon the place. Why the corporation wanted to abandon the place. Why does it now tell me that it will continue to use it irrespective of whether it renews.

Mr. Grant

I am told that there is probably at least one other concentration of industry which matches Canvey Island, but if the hon. Gentleman asks whether there is a concentration of the sort that exists at Canvey Island with its liquid gas storage. the answer is almost certainly "No". However, I shall have to check that.

The contract with Algeria expires in 1980. Negotiations about the terms of the renewal are in hand, but no decisions will be reached by British Gas until the terms become clear. I understand that British Gas regularly reviews the feasibility of the method of storage, but at no time has it contemplated abandoning the site altogether and if the Algerian contract is not renewed it will continue to use the site for storing LNG.

I have noted the hon. Gentleman's anxiety. I shall consider what he said about the construction programme and draw it to the attention of my right hon. Friend the Secretary of State for Energy. Clearly, it is desirable that as much information as possible should be provided.

I appreciate why the hon. Gentleman has been pressing for an inquiry, but I hope that he will accept, in the light of the explanations and assurances that I have given, that this would be unnecessary, not least because we are nearly at the point of concluding the current investigation which covers this sort of ground that concerns him.

I am assured that the investigation is being completed and the report prepared as quickly as possible. I put it to the hon. Gentleman that we should await the outcome of that investigation. Meanwhile, both the county council—

The Question having been proposed after Four o'clock and the debate having continued for half an hour, Mr. DEPUTY SPEAKER adjourned the House without Question put, pursuant to the Standing Order.

Adjourned at eighteen minutes to Five o'clock.