Windblown Dust Deposition Forecasting and Spread of Contamination around Mine Tailings.

Michael Stovern,Omar Felix,Matthew King,Héctor Guzmán,Kyle Rine,Eric Betterton,Avelino Sáez,Wendell Ela

doi:10.3390/atmos7020016

Abstract

Wind erosion, transport and deposition of windblown dust from anthropogenic sources, such as mine tailings impoundments, can have significant effects on the surrounding environment. The lack of vegetation and the vertical protrusion of the mine tailings above the neighboring terrain make the tailings susceptible to wind erosion. Modeling the erosion, transport and deposition of particulate matter from mine tailings is a challenge for many reasons, including heterogeneity of the soil surface, vegetative canopy coverage, dynamic meteorological conditions and topographic influences. In this work, a previously developed Deposition Forecasting Model (DFM) that is specifically designed to model the transport of particulate matter from mine tailings impoundments is verified using dust collection and topsoil measurements. The DFM is initialized using data from an operational Weather Research and Forecasting (WRF) model. The forecast deposition patterns are compared to dust collected by inverted-disc samplers and determined through gravimetric, chemical composition and lead isotopic analysis. The DFM is capable of predicting dust deposition patterns from the tailings impoundment to the surrounding area. The methodology and approach employed in this work can be generalized to other contaminated sites from which dust transport to the local environment can be assessed as a potential route for human exposure.

Highlights

Wind erosion, transport and deposition of particulate matter from contaminated sites may have significant effects on the surrounding environment, especially in arid and semi-arid regions, which are especially susceptible to erosion because of the dry climate and lack of vegetation
In a previous work [11] we developed a windblown dust Deposition Forecasting Model (DFM) that was designed to be used in conjunction with operational weather models to forecast deposition of windblown particulate matter for the Iron King Mine (IK) and Humboldt smelter tailings impoundments in Dewey-Humboldt, Arizona
The results show that the Weather Research and Forecasting (WRF) model slightly under predicts the observed relative humidity, which may be caused by precipitation events that the WRF model failed to forecast since potential dust mitigation due to remnant soil moisture from past rain events are not included in the model

Summary

Introduction

Transport and deposition of particulate matter from contaminated sites may have significant effects on the surrounding environment, especially in arid and semi-arid regions, which are especially susceptible to erosion because of the dry climate and lack of vegetation. In semi-arid mining regions, such as the US Southwest, mine tailings impoundments can be a significant anthropogenic local source of windblown particulate matter [4]. Transport and deposition of particulate matter from mine tailings impoundments on scales of a few kilometers is challenging. Typical regulatory models, such as CALPUFF and AERMOD, have difficulty simulating aerosol transport in topographically complex regions on such small scales

Methods

Results

Conclusion