Class Details

The workshop will explore the nature of random, small-scale variability of contaminant concentrations in soil and the use of “Decision Unit (DU)” and “Multi Increment Sample (MIS)” methods to help generate more reliable data for site investigation and remediation actions. The morning session will focus on field research and DU-MIS guidance published by the Hawai′i Department of Health (HDOH). DU-MIS methods have been used in Hawai′i since 2004, with the first guidance published in 2009. The afternoon session will focus on field experience and case studies overseen by USEPA Region X. The approaches outlined in the HDOH guidance are similar to methods presented in ITRC’s “Incremental Sampling Methodology (ISM)” guidance document (ITRC 2012).

The workshop will begin with the results and implications of a field study of discrete soil sample data variability carried out by HDOH under a grant from USEPA Region 9. This will be followed by a basic review of sampling theory, with a focus on the use of “Decision Units (DUs)” to guide environmental investigations and the collection of large-mass, MI samples to more reliably characterize targeted DU areas. Examples of DU designation and sample collection under different site scenarios will be presented and used to assist in discussions. Case studies will include commercial, residential and agricultural settings, as well as characterization of surface soils, subsurface soils and sediments, and a variety of contaminants including arsenic, dioxins, pesticides, PCBs, munitions related explosives and VOCs. The implications of small-scale heterogeneity on the representativeness and reliability of indoor air and soil vapor data for use in vapor intrusion investigations will also be discussed (same issue, different media).

Case studies to be presented by USEPA Region X staff include the use of DU-MIS for the combined investigation of explosives and metals in soils and further elaboration of laboratory processing of MI samples. Other case studies to be presented include the use of U.S. EPADU-MIS approaches for sediment and eco-risk investigations.

Coordinators:
Harry Craig, 503-326-3689, craig.harry@epa.gov
Kira Lynch, 206-553-2144, lynch.kira@epa.gov