Biofilters are engineered to collect surface runoff in urban ecosystems and filter water through soil media to protect waterways from anthropogenic pollutants. They can effectively capture nutrients, black carbon, microplastics, and heavy metals. However, the use of biofilters as tools for geospatial modelling and records of heavy metal deposition has not been investigated. We sampled biofilters across Jefferson County, KY and analyzed soils for a suite of heavy metals. We generated a geospatial model of metal pollution by normalizing these concentrations for the size of biofilters, catchment size, biofilter age, and soil organic matter concentrations and interpolating between biofilter location point-data. This model of heavy metal accumulation was matched to an EPA-derived tool of predicted heavy metal deposition derived from industry-reported pollution. We predict that heavy metal concentrations match rates of predicted deposition for certain elements, and that downwind proximity to major pollutant sources strongly predicts concentrations of particular metals. We anticipate that results will demonstrate that biofilters can be used not only to capture heavy metals and limit infiltration into waterways, but that they also have the potential to be used as long-term records of pollution in urban environments. As heavy metals are potently toxic to ecosystems and humans alike, being able to quantify or model exposure to these pollutants using biofilters provides a valuable tool to combat environmental injustice.