Ecological Risk Assessment
Ecological Contaminants of Concern (COCs)
The XRF results were compared to the EPA's Ecological Soil Screening Levels (Eco-SSLs) to determine ecological COCs. Eco-SSLs are the concentrations of a contaminant that are toxic to plants, soil invertebrates, and wildlife.
Table 1. Ecological COCs and EPA Ecological Soil Screening Levels
All eight contaminants listed above pose a threat to plants, soil invertebrates, and avian and mammalian wildlife in the area of the site. This result is not surprising considering that much of the site was observed to be devoid of life during the site investigation.
Potential Receptor Populations
Pima County, where the site is located, is home to a variety of plants and wildlife. Table 2 presents a partial list of species living in Pima County, which may be potentially exposed to COCs at the site.
Table 2. Potential Receptor Populations at the Site
Figure 1. Catclaw Acacia Tree (Photo Credit: Emily Henderson)
Figure 2. Deer Scat (Photo Credit: Julaire Scott)
Figure 3. Bird Nest (Photo Credit: Emily Henderson)
Ecological Spatial Distribution Maps
Figure 4: Ecological Lead Spatial Distribution Map
Figure 5: Ecological Arsenic Spatial Distribution Map
Figure 6: Ecological Zinc Spatial Distribution Map
Figure 7: Ecological Manganese Spatial Distribution Map
Figure 8: Ecological Chromium Spatial Distribution Map
Figure 8: Ecological Antimony Spatial Distribution Map
Figure 9: Ecological Cadmium Spatial Distribution Map
Figure 10: Ecological Copper Spatial Distribution Map