The Commonwealth Constitution sets out the responsibilities of the Commonwealth and State Governments. Included in the Constitution are lists of exclusive and concurrent powers (s.51, 52). Where there is no specific mention in the Constitution of a particular power, then the matter is generally regarded as a State responsibility. When the Constitution was drafted in the 1890s, the environment was not regarded as a particular issue of national importance. Accordingly, there is no specific mention of "conservation" or "the environment" in the list of Commonwealth powers. This means that matters such as air and water quality or resource exploitation are left for the States to regulate. Whilst the States may have primary responsibility for the environment, the Commonwealth still has significant powers which can be used to make laws about the environment. For example, the Commonwealth has responsibility for foreign affairs and international treaties and this can be used to pass laws to give effect to international treaties Australia has signed (such as the World Heritage Convention). In some areas, Commonwealth and State powers and operations overlap, resulting in both State and Commonwealth legislation on the same subject matter. In the event of such a conflict, the Commonwealth laws prevail. Under the Constitution, the Commonwealth is directly responsible for Commonwealth land, the management of Australia's external territories and the coastal seas outside the State three-mile limit, (but within the 200km "exclusive economic zone"). Increasingly, Commonwealth and State governments are trying to co-operate to avoid duplication in environmental assessment or regulation. For example, where both State and Commonwealth legislation require an Environmental Impact Statement, then a single process would normally be followed to satisfy both sets of laws. Commonwealth laws are administered by a number of regulatory authorities. In most cases The Department of the Environment, Water, Heritage and the Arts is the relevant authority To find out which particular part of DEWHA is responsible for administering Commonwealth environmental law, ring DEWHA on Freecall 1800 803 772 or visit its web site: http://www.environment.gov.au/.

The main Commonwealth Legislation dealing with the environment is the Environment Protection and Biodiversity Conservation Act 1999. This Act is covered in a separate part of this chapter.

The State is the level of government with primary responsibility for the environment. In this role, the State Parliament has passed many dozens of laws that affect the environment. Some of the more important include the following: Planning and Development (Development Act 1993); Pollution and Waste (Environment Protection Act 1993); Wildlife protection (National Parks and Wildlife Act 1975); Mining (Mining Act 1971, Petroleum Act 2000); Fishing (FisheriesManagement Act 2007); Habitat Protection (Native Vegetation Act 1991); Landcare (Natural Resources Management Act 2004). These laws are administered by a number of different agencies including the State Department of Environment and Heritage, the State Environment Protection Authority ( EPA ), Planning SA and Primary Industries SA. The Acts above are dealt with elsewhere in this chapter and other parts of the Law Handbook.

The environmental responsibilities of local councils are set out in the Local Government Act 1999, as well as other legislation dealing with public and environmental health, development, dogs & cats, drainage etc. Since local councils are created by State legislation, it is possible for the State government to vary the responsibilities of councils. Often there is a tension between the two levels of government, with local councils reluctant to take on new responsibilities without increased resources from State grants or property rates. Generally, issues relating to local amenity or local nuisances are local government responsibilities, however many local pollution problems remain the responsibility of the EPA. Local councils are responsible for "unsanitary conditions", "unsightly conditions of land", barking dogs, backyard chooks, rubbish collection and most local development approvals.

In recent decades, international law has also become more relevant to the environment. Most nations (including Australia) have entered into various treaties, conventions and protocols (agreements) - usually under the auspices of the United Nations. Many of these international agreements are worded so as to be legally binding on nations which sign them. However treaties are not legally binding within a country unless they have been enacted into domestic law. Examples of treaties that have been enacted in Australia include the World Heritage Convention and the Montreal Protocol on Ozone-Depleting Substances. Most environmental treaties have not yet been enacted into Australian law and are not therefore enforceable by Australian citizens. Nevertheless, the main value of such treaties is that they are highly morally persuasive and they are often implemented at a policy (rather than legal) level. South Australia has passed (and the Commonwealth has proposed) controversial legislation which limits the status of international treaties to that of non-binding policy documents only. [See Administrative Decisions (Effect of International Instruments) Act 1995 (SA)]

In many areas relating to the environment, there are no relevant laws, which leaves responsibility up to the individual. This means that governments are reliant on voluntary changes in behaviour as well as a number of education and incentive programs. In the area of pollution and waste, the primary responsibility of individuals is set out in the "General Environmental Duty" in s.25 of the Environment Protection Act 1993, which states that: A person must not undertake an activity that pollutes, or might pollute, the environment unless the person takes all reasonable and practicable measures to prevent or minimise any resulting environmental harm. Whilst a breach of this "duty" does not create a criminal offence, it can lead to action being taken against a person by a government agency or private individuals. These include Environment Protection Orders and Clean-up Orders.