Laggan, J, Townsen, D, Aiello, K, Engel, A & Wagoner, G 2023, 'Determining environmental impacts from historical uranium mining operations using multiple lines of evidence and communicating the process and conclusions to the community', in B Abbasi, J Parshley, A Fourie & M Tibbett (eds), Mine Closure 2023: Proceedings of the 16th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, https://doi.org/10.36487/ACG_repo/2315_021 (https://papers.acg.uwa.edu.au/p/2315_021_Aiello/) Abstract: Determining environmental impacts from historical uranium mining operations at abandoned uranium mines creates unique challenges. The radionuclides and metals associated with uranium ore are naturally occurring in concentrations, such that it is difficult to distinguish between concentrations of radionuclides and metals that are naturally occurring and those that may have been technologically enhanced through mining activities. The term ‘Technologically Enhanced Naturally Occurring Radioactive Material’ (TENORM) is used to distinguish concentrations that resulted from historical mining from naturally occurring radioactive material (NORM) that are not related to mining operations. Multiple lines of evidence (MLE) are used to determine the nature and extent of contamination, understand potential fate and transport pathways, anddevelop a conceptual site model of the extent of mining-impacted material, including TENORM, on mine sites. The MLEs include reviewing historical mining and reclamation activities; conducting interviews with residents and consulting with reclamation staff; reviewing historical and current aerial photographs; analysing geologic stratigraphy, hydrogeology, geomorphology and hydrology; analysing disturbance mapping (as it relates to vegetation changes associated with possible mining or reclamation activities); identifying prominent wind direction; and characterising site data (including visual observations, radiation surveys and surface and subsurface soil sampling).Through the use of MLEs, site media are classified as NORM or TENORM. Areas determined to be TENORM undergo a risk assessment to determine cleanup areas and volumes. Communicating areas of TENORM can be challenging to present to the community. The key to overcoming those challenges is educating the community on how conclusions are drawn and what will be addressed by action or left in place. Keywords: closure, TENORM, NORM, radioactive, community outreach, technologically enhanced radioactive material, naturally occurring radioactive material, uranium