Using coal seam water to increase agricultural production

Coal seam water (CS-water) produced as a by-product of the coal seam gas extraction can be used for agricultural irrigation but requires treatment prior to use to prevent its high sodium content damaging the soil structure. The associated water amendment facilities (AWAFs) used to undertake this treatment are expensive to construct and operate, and result in additional impact on landholders.

School of Agriculture and Food Sciences researchers examined alternative methods of water treatment that would be more environmentally and economically attractive than the construction and use of AWAFs, in this way optimising the benefits provided by the availability of CS-water.

In collaboration with oil and gas producer Santos, the researchers developed a process that allowed amendment within the soil rather than in a dedicated AWAF. This approach to using CS-water proved more robust and would increase agricultural production for landholders while meeting environmental targets. It also proved to be economically beneficial for Santos as they would no longer need to build AWAFs throughout their network.

Santos estimates that by using CS-water and reducing capital and operating expenditure, they would save approximately $500 million across the lifespan of their operations.