This is the data used in the publication "Amendment effectiveness and seasonal variations in a lead contaminated acidic wetland" in Applied Geochemistry (https://doi.org/10.1016/j.apgeochem.2025.106396). This dataset is associated with the following publication: Noerpel, M.R., A.M. Wade, A.R. Betts, J. Goetz, R. Ford, A. Krause, M. Zeolla, D. Cutt, S.M. Wilson, and T.P. Luxton. Amendment effectiveness and seasonal variations in a lead contaminated acidic wetland. APPLIED GEOCHEMISTRY. Elsevier Science Ltd, New York, NY, USA, 185: 106396, (2025).