This updated Incremental Sampling Methodology (ISM-2) web-based document builds upon the 2012 version (ISM-1) and reflects advancements in technology in the ensuing eight years. ISM-type investigation methods have evolved, and regulators have gained more experience in the application of ISM in the field and in the laboratory. The original 2009 survey of regulators and industry environmental experts was updated with current information on ISM practices to measure progress and understand what obstacles are still being encountered.
The updated document includes multiple examples of site scenarios for DU designation and the collection of ISM samples under different field conditions. A separate section on the use of ISM investigation methods to support human health and ecological risk assessments has been added and the simulations in the original appendices have been updated and include a recent study on Student t and Chebyshev discussion of UCL. Current case studies are summarized to provide insight into the potential applications, benefits, and challenges of the approach from recent sites.