Includes all data collected by the US EPA; X-ray absorption spectroscopy (XAS) data on the Lead L3-edge and the Arsenic K-edge and Scanning Electron Microscopy with paired energy dispersive X-ray spectroscopy (EDS) at select spots. This dataset is associated with the following publication: Kastury, F., J. Basedin, A.R. Betts, R. Asamoah, C. Herde, P. Netherway, J. Tully, K.G. Scheckel, and A.L. Juhasz. Arsenic, cadmium, lead, antimony bioaccessibility and relative bioavailability in legacy gold mining waste. JOURNAL OF HAZARDOUS MATERIALS. Elsevier Science Ltd, New York, NY, USA, 469: 133948, (2024).