There are a large range of activities that can lead to pollution or cause environmental harm. Laws controlling these activities have strengthened in the last few decades, with penalties for some offences now up to $1 million. The concept of environmental harm extends to activities which cannot be described as pollution, but which otherwise damage the environment.
This fact sheet explains the laws relating to pollution and environmental harm in Western Australia. See also Fact Sheet: Air quality, Fact Sheet: Contaminated sites, Fact Sheet: Pesticides, Fact Sheet: Industrial chemicals and Fact Sheet: Noise.