A Statistical Summary and Visualization Tool for a 30-year Background Soil and Sediment Metals Data from North Carolina Superfund Sites.

The remediation of Comprehensive Environmental Response, Compensation, and Liability Act or Superfund sites is limited to cleanup to levels no lower than background concentrations. However, both anthropogenically induced and naturally occurring metal concentrations in soil and sediments often complicate this cleanup process. To support informed decisions on heavy metal cleanup and the development of soil heavy metal-related policies in North Carolina, a statewide dataset of background heavy metal data from Superfund site investigations was compiled. The dataset represents background concentrations at 326 Superfund sites found in North Carolina, USA from 1985 to 2015. This 30-year dataset comprises site location data and analytical measurement results for 18 heavy metals in 624 soil and 228 sediment samples, obtained using standard methods. The data are presented in an interactive dashboard, offering summary statistics and graphical representations that can be customized to support specific decision-making needs. The data and Dashboard serve two main goals: 1) to inform and support cleanup decisions and policy development regarding soil heavy metals, and 2) to increase public awareness of the levels of naturally occurring and anthropogenic background heavy metals in soil and sediments across the state. The publicly accessible and interactive dashboard offers a deeper understanding of background environmental conditions in relation to evolving anthropogenic contamination within a broader context.