Environmental Risk Management and Strategic Environmental Assessment (SEA)

 

1. Context

This note has been written to raise awareness of environmental risk management and is aimed at those involved with SEA.  It is intended to promote aspects of environmental risk management that are transferable to SEA.  Further work is planned to build on this initial guidance. 

The Agency’s approach to environmental risk management is described in Guidelines for Environmental Risk Assessment and Management, published jointly by the Environment Agency, the then Department of the Environment, Transport and the Regions, and the Institute for Environment and Health.

The risk management framework has many attributes that can be applied to improve the rigour of assessment in SEA, particularly the use of the source-pathway-receptor model and the consideration of  probability and consequence.

Risk assessment provides a valuable tool to inform decision-making about uncertain future outcomes. One of its strengths is that it can explicitly take account of uncertainties about future outcomes.   In addition, the risk assessment process can be informed by dialogue with stakeholders, which can aid decision-making.   Risk assessment can help SEA and sustainability appraisal by providing a framework to evaluate economic, social and physical outcomes (including impacts on human health and the environment) of proposed policies, plans and programmes..

2. Environmental risk assessment and management – the process

Environmental risk management is a four-stage process.  This is set out below with an indication of how it may be used in SEA.  Risk management decision-making is an iterative process (as is SEA) so stages may need to be revisited as new information comes to light.

2.1  Stage 1.  Problem formulation

The problem at hand should be clearly set out along with any constraints on the assessment and the final risk management decision and its implementation.  Describing the problem in clear and unambiguous terms will assist in selecting the level, or type, of risk assessment required (e.g. qualitative / quantitative) and ensure that risk management decisions are as robust as possible.

Problem formulation involves the following:

·         Setting out the problem in clear and unambiguous terms

·         Defining the spatial and temporal boundaries of the problem

·         Identifying all constraints on the assessment, including those imposed by specific legislative requirements

·         Starting to document areas of uncertainty and assumptions

·         Developing a conceptual understanding (‘model’) of all sources of hazard, all exposed receptors, and the pathways linking them should be developed at this stage.  Without a source-pathway-receptor linkage in place, harm cannot occur.

Table 1.  Flood risk management examples of sources pathways and receptors. 

Sources	Pathways	Receptors
·         Rainfall ·         Sea Level ·         Waves ·         River flows	·         Overtopping and failure of flood defences ·         Breaching of coastal defences and beaches ·         Failure of defence components such as barriers and gates ·         Inundation of floodplains ·         Inadequate urban drainage	·         People ·         Domestic and commercial property ·         Infrastructure ·         E e cosystems

This stage can be applied at the screening / scoping and assessment stages of a SEA.

2.2  Stage 2.  Risk assessment

Risk assessments are undertaken to determine the significance (sometimes referred to as “acceptability”) of the risk(s) and the need for management action to prevent or limit the risk.

Assessments should start at a simple level and can become more sophisticated subject to the nature and complexity of the risks under assessment and the decision-making needs (in risk management this is known as ‘a tiered approach’).  Using a tiered approach should ensure that the complexity of risk assessment is proportionate to the risk.

There will always be an element of subjectivity in risk assessment. It is important to be open about uncertainty and, where feasible, define and agree the approaches to be used with  relevant stakeholders.

Risks assessment takes account of the probability of an event and the magnitude of the consequences of the event (see box 1 below for a simple risk screening example).   Risks associated with an event are assessed using a source-pathway-receptor model - Table 1 gives some examples of possible source-pathway-receptor linkages for flooding.

Consequences can be characterised in a number of ways, including physical ‘harm’, economic and social impacts.  In practice it is likely that assessments will focus on the spatial and temporal nature of impacts on fauna, flora and natural resources (i.e., soil, water and air), including factors such as latency and reversibility and taking account of  the sensitivity of receptors.  Economic consequences might include impacts on resource ‘value’ while social factors such as equity of risk distribution, familiarity, or dread might need to be considered. 

The final stage is the evaluation of the significance of the risk which involves placing it in a context for example with respect to an environmental standard or other criterion defined in legislation, statutory or good practice guidance.

Risk assessment provides a useful too for evaluation, either qualitatively or quantitatively, of possible future environmental outcomes and this can inform identification and consideration of alternatives in a SEA.

Box 1  Illustrative qualitative risk assessment The probability of the receptors being exposed to the hazard.  Example categories: High Medium  Low Very Low The consequences of a hazard being realised.  Example categories: High Medium Low Very Low The significance of the risk is determined by combining the probability with the magnitude of the potential consequences.  A matrix such as the one below can be used to categorise the risk as high, medium, low or very low. In each assessment the meanings of high, medium, low and very low need to be determined and agreed using a descriptive or numerical scale.
Probability                   è	H	M	M	H	H
	M	L	M	M	H
	L	L	L	M	M
	VL	VL	L	L	M
		VL	L	M	H
	Consequencesè The level of risk identified can be used identify the need for further assessment or appropriate risk management measures.

2.3  Stage 3.  Selection of preferred risk management technique

The next stage of the process considers the options available for managing the risk(s),  i.e. what measures are to be taken to prevent or control the identified risk(s). It is likely that more than one possible risk management technique or action is available, including further refinement of the risk assessment, and Options Appraisal is used to provide a balanced assessment of each option so that the most appropriate option can be identified.

The Options Appraisal process involves identifying the advantages and disadvantages of the risk management options (including, environmental, social, economic, technological and management considerations) and ranking them.  Various methods of completing this task are available including Cost-Benefit Analysis, Trade-off Analysis and Multi-Criteria Analysis. The output from Options Appraisal will inform the  risk management decision, which must take account of the nature and magnitude of the risks, the level of uncertainty and any relevant legislative requirements.

This stage can inform the assessment and selection of strategic alternatives and mitigation measures by identifying means to address the risks associated with the source – pathway – receptor linkages identified for assessment at the problem formulation stage.

2.4  Stage 4.  Implementation of preferred risk management technique

The preferred risk management options are implemented and monitored to ensure that they are effective in reducing risks to acceptable levels.

Again the consideration of how the source – pathway – receptor linkage should be managed is key – e.g. using flooding as an example, it would be possible to:

·         address the source (difficult in this case for rainfall, but action to address climate change may reduce the future severity, catchment management);

·         block or alter pathways (install flood defences, set up sustainable drainage systems);

·         remove receptors (steer development away from areas that flood, use flood warning and evacuation).

This stage can be applied to a SEA to inform the development of implementation plans that may be part of the Environmental Report.  These are used to ensure that recommendations from the SEA (e.g., mitigation and monitoring measures) are implemented, perhaps by setting out the scope of future EIA or the next tier in strategic planning (e.g., regional spatial strategies inform local development frameworks; catchment flood management strategies inform Project Appraisal Guidance (PAG2) strategies).

3.0  Dealing with Uncertainty

Uncertainty can arise throughout any risk assessment and risk management process. Types of uncertainty can include:

ð      model - models may not be accurate or complete

ð      environmental - natural variability may not represent conceptual model assumptions

ð      knowledge – scientific data may be incomplete

ð      sample  - sample measurements may be inaccurate or the validity may be queried

ð      data - data may be extrapolated or interpolated from other sources

ð      scenario - scenarios might not fully describe the problem

Although uncertainty cannot be eliminated, it can sometimes, but not always, be reduced by collecting more information.  It is important to acknowledge all uncertainties including data gaps and assumptions.  Evaluating different sources of uncertainty can help understand how much confidence can be placed in the risk assessment and aid robust decision-making.

Methods for analysing uncertainty range from simple to complex. A simple sensitivity analysis can, for example, be undertaken to examine the behaviour of a model by measuring the variation in outputs resulting from changes to its inputs. 

Documentation

It is important that good documentation is maintained throughout the risk assessment and management process.  This will form an audit trail to record assumptions, areas of uncertainty, information sources, and justifications for decisions.

Good documentation is also essential for communication of risk management decisions and should take account of the potential audience needs.