The discharge of mine water into natural receiving waters can have potential impacts on the water quality and aquatic organisms in those environments. Effective environmental monitoring is essential so that mining impacts can be accurately detected, and relevant mitigation procedures can be carried out. The diffusive gradients in thin films (DGT) technique has the potential to be an important tool in regulatory compliance monitoring and environmental risk assessments. It measures the flux of metals accumulated in the resin gel over a given time period, which is used to calculate the concentration of metals that are potentially bioavailable in the bulk solution to which the DGT was exposed. As the Ranger Mine, surrounded by Kakadu National Park, NT, is currently undergoing rehabilitation, there will be a need for long-term monitoring of the mine-site. This project is investigating the use of DGT as a monitoring tool in Kakadu and Arnhem land waterbodies for key Contaminants of Potential Concern (COPCs), which have the potential to be passively discharged from the mine site following rehabilitation. The creeks surrounding the mine have unique physico-chemical characteristics; extremely low hardness, low ionic content and pH. The objectives of this project are 1) to explore the use of DGT for environmental monitoring in these soft-waters, and 2) to validate the approach against biological-effects data to ensure the DGT data can be appropriately interpreted. For this, a series of toxicity tests will be undertaken alongside DGT exposures. This presentation will discuss the key challenges of using DGT in this unique environment and the expected outcomes from the project.