Water pollution

Water pollution occurs when harmful substances contaminate a stream, river or lake, an ocean or groundwater. This can be unhealthy to the environment and its wildlife, and humans.

We investigate most water pollution incidents under the Environmental Protection Act 1994. This responsibility is shared with other government agencies. The Department of Environment and Science will investigate major environmental incidents.

Contact the Department's 24-hour Pollution Hotline on 1300 130 372.

Types of water pollution

There are 2 types of water pollution sources:

  • point source pollution
  • non-point source or diffuse pollution.

Point source pollution is a discharge or outflow from a location you can see, such as a pipe. Examples include:

  • wastewater discharged legally or illegally by a manufacturer or wastewater treatment facility
  • contamination from leaking septic systems, chemical and oil spills, and illegal dumping.

Non-point source or diffuse pollution doesn't come from one recognisable source. Runoff from agricultural and urban sources can enter the waterway from any point. In urban areas, runoff into stormwater drains can carry pollutants from:

  • garden fertilisers, chemicals, and garden soil
  • lead, oil, and tyre rubber from roads
  • bacteria and micro-organisms from animal droppings
  • litter items, such as plastic bags, drink containers, food wrappers and cigarette butts.

Impacts of water pollution

Water pollution can result in environmental damage, poisoned wildlife, and human health problems. Rubbish such as plastic can choke and kill animals living in or near waterways.

Land clearance and extraction for agriculture, forestry management and new developments can cause soil erosion. After rain, surface water runoff carries this soil and anything it contains into waterways. This can cause:

  • silt to build up in the waterway
  • algal blooms to grow, which creates areas of low oxygen that fish and aquatic life cannot thrive in
  • death of aquatic plants and animals.

Chemicals and other contaminants in the water can also have negative effects on our health. Sewerage discharge into coastal waters may wash up on our beaches and people can fall ill if they swallow polluted water while swimming or surfing. It can also have harmful effects on aquatic wildlife, such as shellfish. Eating contaminated seafood poses serious risks.

How we are addressing the problem

Our approach is proactive. We regulate Environmentally Relevant Activities that have the potential to damage or pollute the environment.

We maintain over 1500 devices that improve the quality and control of stormwater runoff that flows into our waterways.

Our Catchment Management Unit undertakes water quality monitoring programs. The Unit monitors the ecosystems, estuaries and groundwater sources that feed into our waterways. For information about this program and the health of our waterways, contact our team: