Risk Assessment Methods

There are numerous risk assessment methods available. It may be useful to use the following Australian Standards to provide further guidance :

1. AS/NZA 4360 Risk Management.
2. HB 203:2006 Environmental Risk Management : Principles and Process

Factors which may be considered in determining significance are :

• regulatory requirements;
• available knowledge on the issue;
• level of concern of interested parties; and
• the relative significance of this impact with the contribution of other organisations.

The most commonly used technique for determining the significance of environmental impacts is a matrix combined with a rating system based on :

• the likely frequency of impact; and
• the likely severity of an impact.

Criterion Based Determination of Significance

Criterion based determination of significance uses a checklist approach.

A series of questions is developed to create a decision tree. Fro example :

• Is the aspect/impact related to the environmental policy ?
• Is there a legal requirement?
• Will an incident generate species or biodiversity risk ?
• Is there likely to be public outrage if the aspect is not controlled ?
• What is the relative risk (does it fall within the pre-determined significance range e.g likehood x severity) ?

If the answer to any of the questions is yes the impact can be generated from the aspect may become significant (dependant on the organisations significance determination methodology). The hierarchy of questions is relative and will vary from one organisation to another.