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Chemical, Biological, Radiological or Nuclear (CBRN)

Defra: Strategic National Guidance - The decontamination of the open environment exposed to CBRN substances or material

4. Management approaches to environmental decontamination

4.1. Although the hazardous properties of different CBRN substances vary considerably, methods for decontaminating and restoring the environment to normal use share some common factors. Figure 1 and Figure 2 [PDF 723KB] illustrate typical decontamination and waste management strategies needed to deal with persistent or non-persistent types of chemical, biological or radiological substances, released outside into either urban or rural environments. The strategies are based on simplified incident profiles explained in Annexes 1 to 5 [PDF 855KB] of this document. In addition, for CBRN incidents involving animals Defra has separately developed a contingency plan to address disposability issues⁽²⁴⁾.

4.2 Important local resources

4.2.1 Irrespective of the precise circumstances of the incident, successful recovery will partly depend upon the ready availability of the following local resources that may already be in place to deal with, for example, major chemical incidents.

4.2.2 Decontamination solutions. Chlorine-based bleaching or sterilising solutions are highly effective at removing both chemical and biological contamination. The most widely available sterilising solutions are calcium hypochlorite, sodium hypochlorite and sodium dichloroisocyanurate (FiClor), which are all commonly used to sterilise bacteria in swimming pools. A decontamination solution of 0.5% hypochlorite in water would be effective against many substances.

4.2.3 Water supply. An available water supply is needed both to prepare decontamination solutions and to rinse decontaminated surfaces. In rural or coastal environments freshwater from watercourses or saltwater from the sea provide a readily available water supply. In urban environments water is usually supplied via fire hydrants, which should be properly maintained and periodically tested, especially near buildings that may be a target for terrorists. Fire hydrants are owned by water companies and tested by the Fire Service.

4.2.4 Drainage management equipment. Run-off water and rinse water from decontamination will contain high concentrations of chlorine. The waste water must be intercepted and treated to neutralise its chlorine content which is hazardous to the environment. In urban areas the road drainage system is particularly vulnerable. Storm water drains may need to be blocked or their effluents diverted to holding tanks before decontamination is carried out, in accordance with the Water UK Protocol for Disposal of Contaminated Water.

4.2.5 ISO containers. Decontamination methods for dealing with persistent CBRN substances will tend to generate large amounts of solid waste. These will normally require temporary storage in ISO containers, especially in the case of radioactive wastes.

4.3 Partner organisations

4.3.1 Recovery from a CBRN incident will involve a partnership between the public local authority and private sector organisations. Commercial contractors will be likely to undertake decontamination and clean-up operations on behalf of the local authority. In addition the wastes, which are generated, are also likely to be managed by commercial organisations, e.g. private sector companies operate many hazardous waste landfill sites and incineration facilities.

4.3.2 Water supply and sewerage services. Water supplies and sewerage services to a particular area are provided by the local water companies, although it should be noted that in some areas two separate companies may be involved in the provision of services. Their expertise in local drainage systems and effluent interception will be very important when planning wet decontamination operations, especially to predict and avoid impacts on watercourses and drinking water supplies.

4.3.3 Landfill site operators. Contaminated soils or solid residues from liquid waste slurries are likely to be disposed to a hazardous waste landfill. Disposal arrangements will need to be discussed and agreed with the landfill operator.

4.3.4 Clinical waste incineration companies. Bags of contaminated clothing and protective equipment that are lightly contaminated with CBRN substances are combustible and may be destroyed by incineration processes. In principle these wastes are similar to other hazardous chemical, biological or radioactive substances which are commonly disposed from hospitals and research establishments as 'clinical waste' to incineration plants in the UK.

4.3.5 Insurers. It is the responsibility of land owners and occupiers to ensure adequate insurance cover to meet the cost of dealing with the consequences of a CBRN terrorist incident, as it would be for any other potentially serious incident such as fire or flood. However in many cases as the CBRN risk is so open-ended insurers are increasingly less willing to cover the risk to private property. Commercial property, however, can be covered by the Pool Re scheme set up by the insurance industry and underwritten by HM Treasury. In the public sector, central and local government bears its own risk.

Powers exist under the Local Government and Housing Act 1989 for the Government to make financial assistance available to local authorities following an emergency or disaster involving destruction of, or danger to, life and property. The Bellwin Scheme exists for this purpose, although it is discretionary and has not to date paid out for the costs of dealing with past terrorist incidents. The Local Government Act 2003 allows for alternative grant making powers including the provision for ministers to make special grants to local authorities The local authority has a legal duty of care towards its contractors and may be vicariously liable for the actions of recovery contractors operating under the authority's instructions and directions. Military assistance may be required for the transportation of waste to disposal locations because commercial waste transport contractors also face similar insurance difficulties.

⁽²⁴⁾ Foot and Mouth Disease Contingency Plan. Version 3. March 2003. A disposal strategy for contaminated animal carcasses is set out on Pages 40 - 42 of the contingency plan, which offers a hierarchy of preferred disposal options based upon incineration, rendering and landfill.
www.defra.gov.uk/footandmouth/contingency/index.htm [External website]