Water pollution can be divided into two sources:
A ‘point source’ discharge enters a waterway from an identifiable location, such as a pipe. Many industries use this method, while others discharge to the sewerage system. Point source and sewerage system discharges from an environmentally relevant activity must be licensed under the Environmental Protection Act 1994.
A ‘diffuse’ or ‘non-point source’ discharge does not enter a waterway from one identifiable location. For example, run-off from agricultural and urban sources usually enters a waterway at one point, including stormwater drains.
Point and diffuse sources in Queensland
Point source discharges to waters in Queensland originate from sewage treatment plants, refineries, abattoirs, mining, aquaculture and piggeries/feedlots. In Queensland, the majority of nutrients in point source discharges are from sewage treatment plants, although other industries can also contribute significantly. Chemical or heavy industries typically produce small amounts of nutrients but higher amounts of other pollutants such as metals, pesticides, acids/bases or organic matter. Diffuse sources are typically the major contributor of suspended sediment loads to coastal waters but are not licensed and, therefore, not discussed here.
Wastewater treatment plants are mainly concentrated in coastal areas of Queensland and release treated wastewater to estuaries, bays and open coasts. Approximately two-thirds of major wastewater treatment plant discharges in coastal Queensland are in south-east Queensland. Levels of treatment include:
- primary (removal of suspended and organic matter)
- secondary (removal of biodegradable organics, suspended solids and nutrients)
- tertiary (removal of residual suspended solids, nutrients and pathogens).
In Queensland, most treatment plants use secondary or tertiary treatment with some type of disinfection.
Find out about monitoring and tracking of water releases.
For further information, email firstname.lastname@example.org.
Geographical Information System (GIS) layers with information on the location of point source discharges can be found on WetlandInfo – your first-stop-shop for wetland management resources in Queensland.
If you notice a reduction in water quality, or any activity affecting water quality, report it to the department or your local council.
If your enquiry relates to pollution issues arising from a commercial source or fish kills, call the department.
If your enquiry relates to a pollution issue arising from a residential property, please contact your local council.
For any information on illegal dumping or pollution of our waterways, please contact the department.
For data and reports on water pollution visit our publications page.