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Risk site identification and planning


Although many premises, activities and materials pose a hazard to the environment, the potential impact of an emergency incident is not always realised. This is because three components need to be present before a risk to the environment exists: a source (hazard), a pathway and a receptor. If any part of the source–pathway–receptor link is missing or removed, then there is no risk to the environment. Examples of sources, pathways and receptors are shown in the table below and illustrated below.

Environment agencies recommend that all operators assess the nature and level of environmental risk that their site poses by carrying out an Environmental Risk Assessment (ERA). At sites regulated by environment agencies this is often a requirement of their permit, or it will be assumed to be done if the operator can meet the requirement for the permit they are applying for. In other cases, environment agencies will undertake the assessment or parts of its themselves as part of their assessment of the permit application.

FRS personnel involved in incident planning should understand how environmental risk assessments (ERA) are completed, as this will help them develop their own plans for high risk sites. They may also have to undertake such assessments themselves or with environment agencies for example at illegal or abandoned sites where the operator is unknown or unwilling to act.

The process itself is usually completed using a two stage process. The first stage is a simple risk screening assessment followed if a potential risk is identified by a more detailed assessment. Further details can be found in the EA’s guidance ‘Risk assessments for your environmental permit’ guidance.

These three photographs show the source – water containing silt, the pathway – the drainage system and the receptor – the aquatic ecosystem into which the silty water is discharged

Pollution sources, pathways and receptors

Pollution sources and hazards

  • Hazardous materials
  • Eco-toxic
  • Organic or inorganic
  • Low hazard materials
  • Radionuclides
  • Pathogens
  • Combustion products


  • Dry ditch
  • Stream
  • River
  • Lake
  • Coastal waters
  • Permeable ground
  • Surface water drainage system
  • Foul sewer system
  • Air
  • Roadways
  • Land drains
  • Flood water.


  • Humans
  • Plants
  • Animals or birds either:
    • Directly for example drinking water or contact with contaminated water, soil, inhaling smoke


    • Indirectly for example, through the food chain, a reduction in dissolved oxygen levels following discharge of high BOD substance