The Environment Protection and Biodiversity Conservation Act 1999 (Cth) (‘EPBC Act’) environment impact assessment process applies to actions that have a significant impact on a matter of national environmental significance.

The EPBC Act does not define “significant”. Although “impact” is defined in section 527E of the EPBC Act does define “impact” to include:

• events or circumstances that are a direct consequence of the action; and
• the event is a secondary consequence of the action and the requirements in section 527E(2) are met.

The Minister for the Environment Protection, Heritage and the Arts (“the Minister”) has issued Administrative Guidelines For Determining Whether An Action Has, Will Have, Or Is Likely To Have A Significant Impact On A Matter Of National Environmental Significance Under the EPBC Act 1999 (“the Guidelines”).

The Guidelines set out criteria by which to assess the impact a development may have on each matter of national environmental significance under the EPBC Act. The Guidelines state that in order to decide whether an action is “likely to have a significant impact”, it is necessary to take into account the nature and magnitude of potential impacts.

“Significant” - In determining the nature and magnitude of an action's impact, it is important to consider matters such as:

• all on-site and off-site impacts;
• all direct and indirect impacts;
• the frequency and duration of the action;
• the total impact which can be attributed to that action over the entire geographic area affected, and over time;
• the sensitivity of the receiving environment; and
• the degree of confidence with which the impacts of the action are known and understood.

“Likely” - is described in the Guidelines as:

• not necessarily a more than 50% chance of occuring; rather
• a real or not remote chance or possibiltiy.

The Minister must take into account the Precautionary Principle in deciding whether an action is likely to have a significant impact on a matter of national environmental significance.

The EPBC Act definition of the “Precautionary Principle” is that lack of full scientific certainty is not a valid reason for refusing to prevent degradation of the environment where there are threats of serious or irreversible environmental damage; (section 391 of the EPBC Act).

• The EPBC Act on Austii

• Austraian Government - Department of Environment, Water, Heritage and the Arts - EPBC Act home

• Austraian Government - Department of Environment, Water, Heritage and the Arts - Administrative Guidelines For Determining Whether An Action Has, Will Have, Or Is Likely To Have A Significant Impact On A Matter Of National Environmental Significance Under the EPBC Act 1999