There is a lot of media coverage of the risk to water quality in Australia, from Coal Seam Gas (“CSG”) wells. And rightly so, the sheer scale of the proposed CSG industry will cause the public to doubt the government’s commitment to managing the environmental issues.
The community fear is that land and aquifer degradation will lead to large areas of farmland unable to sustainably produce crops, cattle or some other food resource. The inference is that intensive drilling or mining activities liberate large quantities of saline or mineral rich bore water from coals seam aquifers. What happens when these large volumes of water are brought to the surface and stored in evaporation ponds? Well the current plan is to treat this produced water and reduce the waste water volume by reverse osmosis, mechanical vapour recompression or some other means. Once the waste water is processed into a smaller concentrated liquid form it should be able to be evaporated.
Well the bad news is that these ideas do represent a threat to surface land because concentrate takes much longer to evaporate and when it does, if its not properly managed, it can create saline dust plumes which can destroy farmland. Additionally if floods affect concentrate storage ponds, uncontrolled releases can occur or seepage back into another aquifer may occur, causing local bore water problems. These problems have been documented in the USA where the CSG industry has been active for over 20 years. Although the USA experience is different because the coal seam depth and geology of the CSG regions, the results can be used to help Australia improve this valuable industry while maintaining strict environmental management practices.
The good news is that new technologies are emerging that can help control and eventually eliminate environmental damage on agricultural land. PurePro and its partners have developed a Zero Liquid Discharge model which we are presenting to gas companies in Queensland. The future for CSG waste water processing will offer opportunities to recycle water and remove the solids, like sodium, for reprocessing into higher value end products.
All in all the future looks bright for both the CSG and water processing industries to demonstrate that the LNG industry in Eastern Australia can make a positive contribution to the agricultural community.