Development of a dust deposition forecasting model for mine tailings impoundments using in situ observations and particle transport simulations

- A site specific dust deposition forecasting model is proposed.
- The model is developed from both theoretical simulations and empirical relations.
- The model is designed to be initialized by operational weather forecasts.
- The model's preliminary validation is conducted using observed soil contaminant tracers.

Mine tailings impoundments in arid and semiarid environments are susceptible to wind erosion due to their fine grain silt and sandy composition and lack of vegetative coverage. Aeolian transport of particulate matter from these mine tailings impoundments are potential hazards to human health due to the presence of metal and metalloid contaminants. Predicting windblown transport of mine tailings material can be a useful tool in characterizing the risk and environmental impact on neighboring communities. This work presents a model that can be used to forecast the transport and deposition of windblown dust from mine tailings impoundments. The deposition forecast model uses in situ observations from a tailings field site and theoretical simulations of aerosol transport to parameterize the model. It includes a method for simulating deposition patterns for several different size fractions and can be translated to other regions and applied to different windblown dust sources. The model was developed using data from the Iron King Mine tailings in Dewey-Humboldt, Arizona, a Superfund site that is heavily contaminated with lead and arsenic. A preliminary verification of the model was conducted using topsoil measurements of lead and arsenic as tracers of windblown dust from the tailings impoundment. The tailings tracers support the predicted deposition patterns generated by the deposition forecasting model.