How does it occur?
Many industrial process have the potential to increase salinity levels in rivers.
- Effluent from towns, intensive agriculture and industry can contain high levels of salt.
- Industrial wastewater can have high levels of salt in it due to industrial processes that concentrate salt in water. For example, In coal-fired power stations, water used for cooling is partly evaporated, which concentrates the salt in the water discharged from the coolers.
- Working coal mines need to manage saline water from groundwater seepage and from rainwater coming into contact with mine workings or spoil.
- Mining activities undertaken before the development of strict rehabilitation requirements have led to abandoned mines being a major source of salt in some sub catchments.
The impact of industrial salinity
Salinity is influenced by, and has an impact on our industrial sector. Water of low salinity is an important requirement of the manufacturing and food processing industries. However, some industrial processes concentrate salt in the water they use. The future development of theses industries in regional locations is at risk from rising salinity levels.
What is being done?
Most industries recycle large amount of saline water for on site use, however, some need to dispose of saline water by discharging it into rivers.
In the Hunter, mines and power stations have entered into a scheme that allows the discharge of saline water at times which do not impact on other users needs. However, if the background level of salinity increases, the viability of this scheme, in which over $100 million has been invested, will be threatened. Alternatives to this scheme would incur a major cost to these industries.
Guidelines for discharging waste water into rivers have been imposed for the Hunter River Salinity Trading Scheme.
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Page last updated: 26 September 2013