AN INVESTIGATION OF TRACE METAL CONCENTRATIONS IN SEDIMENT AND SURFACE WATER OF THE WOOLSEY WILDFIRE AREA, CALIFORNIA
Previous environmental inventories of trace metals in burned areas (Abraham et al., 2017, Burton et al., 2016) found elevated concentrations of Cu, Pb, Ni and Zn in ash from burned residences rather than wildland areas. Our preliminary data show elevated concentrations of Mn, Co, Zn, Cr, Ni and Pb in the burned areas compared to non-burned ten months post-incident. Although these metals are naturally abundant, it is possible that elevated concentrations were introduced by burned materials such as wiring, fencing and household items. Our sediment samples from stream beds produced at or below detection level amounts of elements compared to those from open, dry areas, suggesting that the unusual amount of precipitation in winter 2018-19 had a diluting effect.
The Woolsey fire took place in a relatively wild region close to a major metropolitan area, and affected multiple counties and stakeholders. Understanding the mobilization of trace metals and other dissolved solids through the landscape will have implications for environmental policy and urban planning.