In order to prioritise areas for action in your environmental management system (EMS), you need to assess which of the environmental aspects and impacts you have identified are the most significant.
Certification bodies for EMS standards such as ISO 14001 will want to see evidence that your business has assessed its environmental aspects and impacts formally and logically. This will usually require the use of a system that rates and scores the relative significance of each.
Even if you are not seeking formal certification, assessing the significance of environmental aspects and impacts will help you to decide what the key environmental issues are. And how to make effective use of your resources by focusing on areas of high risk or most benefit.
Different operating conditions can have a large effect on the significance of an environmental impact. It is important you evaluate the significance of your identified environmental aspects under both normal operating conditions and other operating conditions, such as:
- abnormal operations - eg factory start-up after a holiday shutdown
- accidents or emergencies - eg fire
- past activities on the site
- planned activities
Methods for assessing environmental significance
There is no set approach for evaluating significance but, whatever approach you choose, it is important to record the reasons for your decision.
A simple method is to ask whether the aspect has the potential to seriously damage the environment, whether it is controlled by legislation or if it is of concern to customers and consumers. If the answer is yes to any of these questions, then it is significant and should be managed by your EMS.
You could develop a point scoring system by awarding a numerical score to each environmental aspect. You should consider those scoring more than an agreed amount as significant. For example, you could award each environmental aspect a score to reflect the relative importance of:
- the severity of environmental damage
- reaction of interested parties such as customers and environmental groups
- quantity - eg the volume of the waste type
You should multiply each of the scores by a weighting factor, which reflects the overall importance of that particular criterion at your site or business. Adding these four scores together will produce a total score for that environmental aspect for normal or other operating conditions. It is up to you to decide the threshold score for environmental significance.
You should record the results of the evaluation, and the basis for your decisions regarding significance, to show that the exercise has been undertaken in a well-structured way. You should make sure that you review the significance of your environmental aspects and impacts on a regular basis.