CSG companies are seeking commercial uses for salt produced from the treatment of associated water.
CSG associated water is brackish. On average, it has about a sixth the salinity of seawater, but salinity can vary between 200-10,000 milligrams per litre total dissolved solids (TDS), which compares to 35,000 mg/L TDS in sea water.
Good, palatable drinking water is less than 500 mg/L TDS, although water more saline that this is still safe for human consumption and is suitable for stock use.
Some associated water can be used untreated for stock water, dust suppression, coal watering or cooling of power stations. But other water will have to be treated and producing this treated water will also produce salt.
CSG producers are examining beneficial uses for produced salt, such as use in chemical industries and industrial processes. Salt can be used to make soda ash (for use in producing glass, paper and washing powder) or caustic soda (used in producing soap and aluminium).
But if companies cannot find a commercial use for salt, they may seek environmental approval to inject it into deep underground saline aquifers. Otherwise, they could bury the salt in a purpose-built, government-approved industrial waste landfill that would be encapsulated to prevent migration of salt from the site.
Salt will not contaminate farming land or groundwater
CSG wells are cased with steel and cement to prevent contamination of aquifers. Any associated water used by landholders must meet standards in line with irrigation water standards.