Nutrien Redwater Fertilizer Operation Air Quality Assessment

Millennium EMS Solutions Ltd. conducted an air quality assessment of trace hydrogen fluoride (HF) emissions that emanate from the phosphogypsum storage areas (as well as from a number of stack sources) at the Nutrien Redwater Fertilizer Operation prior to Nutrien shutting down the phosphate plant and reclaiming the land. The amount of HF emitted by the gypsum storage area fugitively was unknown so MEMS quantified the fugitive emissions by simulating the storage area as an area source and then back-calculating the emissions, specifically using the method of “inverse dispersion” modelling, from downwind path-averaged measured ambient concentrations. Once the emissions rate from the gypsum storage area had been quantified, MEMS was able to assess the ground-level impact of the HF emissions over a 30 x 30 km study area.