Commonwealth tool for an EIA is the Environment (Protection) Impact of Proposals Act 1974.

The object of the Act is to ensure, to the greatest extent that is practicable, that matters affecting the environment to a significant extent are fully examined and taken into account in relation to Commonwealth actions and decisions.

The Act defines environment as including 'all aspects of the surroundings of human beings, whether affecting human beings as individuals or in social groupings'.

There are two triggers for the Act:

1. there must be a Commonwealth decision or action; and
   
2. the proposal must be environmentally significant (the decision as to whether or not a proposal is environmentally significant rests with the Commonwealth referral agency).

If a proposal meets these two tests, it must be referred to the Environment Protection Group of Environment Australia for assessment under the Act.

There are four levels of assessment under the Act. These are:

1. internal assessment with no public review (usually based on a State assessment process);
2. Public Environment Report (this goes out for 4 weeks public review);
3. Environmental Impact Statement (this typically goes out for 6 weeks public review); and
4. Public Inquiry (used infrequently).

The Minister for the Environment and Heritage determines the level of assessment required.

1. Proposal requires Commonwealth approval and is environmentally significant. Proponent is designated.
2. Proponent provides initial information about the proposal and expected environmental impacts.
3. Minister directs EIS (2 weeks from step 2).
4. Environment Australia prepares draft guidelines for the content of the EIS, in consultation with the proponent. These are released for public review for 4 weeks, prior to finalisation (6 - 8 weeks).
5. Proponent prepares draft EIS in accordance with guidelines.
6. Draft EIS released for public review (4 - 8 weeks).
7. Proponent prepares final EIS addressing public comments and submits this to Environment Australia.
8. Minister for the Environment and Heritage advises if the proposal is environmentally acceptable and any conditions needed for the protection of the environment (6 weeks from step 7).

Administrative Procedures under the Act outline requirements for an EIS. In practice, Environment Australia will prepare guidelines specific to a proposal. The generic content is as follows:

To the extent appropriate in the circumstances of the case, an environmental impact statement shall -

1. state the objectives of the proposed action;
2. analyse the need for the proposed action;
3. indicate the consequences of not taking the proposed action;
4. contain a description of the proposed action;
5. include information and technical data adequate to permit a careful assessment of the impact on the environment of the proposed action;
6. examine any feasible and prudent alternatives to the proposed action;
7. describe the environment that is likely to be affected by the proposed action and by any feasible and prudent alternative to the proposed action;
8. assess the potential impact on the environment of the proposed action and of any feasible and prudent alternative to the proposed action, including, in particular, the primary, secondary, short-term, long-term, adverse and beneficial effects on the environment of the proposed action and of any feasible and prudent alternative to the proposed action;
9. outline the reasons for the choice of the proposed action;
10. describe, and assess the effectiveness of, any safeguards or standards for the protection of the environment intended to be adopted or applied in respect of the proposed action, including the means of implementing, and the monitoring arrangements to be adopted in respect of, such safeguards or standards; and
11. cite any sources of information relied upon in, and outline any consultations during, the preparation of the environmental impact statement.