For many years there were no relevant laws leaving responsibility up to the individual. This meant that governments were reliant, and certainly to some degree still are reliant, on voluntary changes in behaviour as well as a number of education and incentive programs.
In addition, the Environment Protection Act 1993 (SA) sets out the General Environmental Duty in section 25, 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 other private individuals or a government agency. These include Environment Protection Orders and Clean-up Orders.