This HEER Office field study evaluates the nature of random variability within and between co-located, discrete soil samples and discusses implications for the continued use of discrete soil (and sediment) sample data for final, decision making purposes as part of an environmental investigation. Hundreds of co-located discrete samples were tested at three sites known respectively to be contaminated with arsenic, lead and PCBs. Part 1 of the study presents the field study design and the resulting data. Part 2 of the study discusses implications for use of discrete data for site characterization and risk assessment purposes.
Included below are links to the 2015 field study report (separate data files provided in Excel), PowerPoint slides and recorded presentations for Parts 1 and 2 of the study presented in 2016, a two-part paper on the study published in January 2017 and a summary of the field study presented to USEPA in August 2017. Refer to the "Discrete Soil Sample Variability Field Study" folder on the HEER Office YouTube channel for recorded presentations.
A brief comparison of discrete vs Multi Increment sampling methods is included in the presentations. Refer to the four-part, Technical Guidance Manual series posted to the HEER Office webinar webpage in June 2017 for a detailed overview of DU-MIS investigation methods, including: 1) Systematic Planning of Site Investigations, 2) Designation of Decision Units, 3) Sampling theory and characterization of DUs (discrete vs MIS) and 4) DU-MIS field implementation.