Mayor of London
Greater London Authority
The Queen's Walk
23rd July 2007
I am responding to your letter of 6 July to Craig Bell about HSE's land use planning advice and the recent consultation on proposals for revised policies to address societal risk around major hazard installations.
I welcome the Greater London Authority's response to the societal risk consultation exercise and the reports it has commissioned on the impact of HSE's land use planning advice. However, I believe that the concerns which you have expressed may be based on misunderstandings in the reports prepared for GLA. The picture presented is misleading and should not be used as a basis for determining policy.
For instance it seems that the reports assume that all developments within the proposed consultation zones would be prevented. This is far from the reality. It is clearly not possible to predict exactly what the impact of these proposals would be in London, but currently only about one in ten of development proposals in consultation zones are "advised against" by HSE. As you know the decision on whether or not a development should be allowed to proceed lies with the planning authority not with HSE. We take view that planning authorities, representing as they do local people, should take decisions but only on basis of the full facts, including explosion and other risks.
I would like to explain some of the key points on these issues.
I fully understand your concern about the need for new and better housing in the GLA area. However, HSE believes that such decisions should be taken on the basis of the best available knowledge at the time. In particular, with our remit on protecting people from risks associated with industrial activities, we want to make sure that planning authorities have access to information and advice to enable them to balance the desirability of any new development against the need to control the risk of harm to people from major hazard installations.
The law of course requires that risks from such sites are properly managed and that all necessary measures are put in place to prevent major accidents and to protect people living and working around such sites. However, no matter how stringent on-site controls may be, the possibility of a major accident can never be entirely eliminated. Controls applied through the land use planning system help to minimise and mitigate this residual risk.
I must emphasise that the decision on whether a particular development should be built is one for the Local Planning Authorities to make. They have to take account of all material considerations (including health and safety advice from HSE). I can assure you that HSE does all it can to ensure that the advice it provides accurately reflects the risk from major hazard installations.
HSE has provided land use planning advice around gasholders for almost 20 years. During this time the nature of this advice has changed as our understanding of the risks and new knowledge becomes available. The last revision was based on a review of major accidents from gasholders including information provided by National Grid on the nature and frequency of gas releases from holders, and information contained in Safety Reports. Our current advice is consistent with the analysis contained in safety reports produced by the operators of gasholder installations.
There are real safety issues on land development around gasholders and while it is true to say that a major incident has not occurred for 70 years, in recent years there have been, on average, three or four large gas escapes per year from gasholders in this country; any one of these could have led to a major incident if the escaping gas had found a source of ignition. In the past, gas releases have dispersed safely mainly because there were large clear areas around gas holders. Development of land near to these sites (particularly if of an intensive multi-storey nature) both increases the number of potential ignition sources and the number of people who could subsequently be affected by any incident. The explosion at Buncefield in December 2005 has shown that it is imprudent to rule out the possibility of hitherto unforeseen major incidents occurring at such sites.
The consultation on societal risk is the result of work done by a cross-governmental Task Group with representation from HSE, the Department for Communities and Local Government, the Department for Business Enterprise and Regulatory Reform (formerly DTI) and other Departments with an interest in this issue, as well as officials in the Devolved Administrations in Scotland and Wales. The Group has been looking at how to ensure that very low frequency but high consequence (in terms of harm to people) events are properly considered when deciding on on-site control measures and off-site land use planning.
This is not about automatically stopping housing or other development from going ahead around major hazard sites. It is about achieving the right balance between the risks to people that society is willing to accept and the benefits that development of land around major hazard sites can bring. The consultation seeks views on how best to achieve that balance and how to ensure that local planning authorities have all the information they need in order to make properly informed planning decisions.
At this time no decisions have been made about whether and how societal risk should be taken into account. The views of all those who have taken part in the consultation, including those of the GLA, will be considered by the Task Group and Ministers as part of the decision making process.
I hope that my comments help to clarify HSE position. However in view of your concerns, it may be helpful for you to meet with me, to discuss them in greater detail. If you agree I will ask my office to contact yours to arrange this.
Deputy Chief Executive