Soil contamination is often unevenly distributed, making it difficult to obtain representative samples using traditional discrete sampling methods. Incremental sampling methodology (ISM) addresses this challenge by collecting numerous soil increments from a defined area, combining them into a single sample, and following structured processing and subsampling procedures. This approach reduces data variability, provides a more reliable estimate of average contaminant concentrations, and supports more defensible environmental science decision-making.
Building on the original Incremental Sampling Methodology (ISM-1, 2012) guidance and subsequent Clarifications to ITRC 2012 ISM-1 Guidance (2020), this Incremental Sampling Methodology Update (ISM-2, 2020) includes advancements in technology, lessons learned from field applications, and expanded regulatory experience. The guidance provides practitioners with recommendations for planning, collecting, processing, and interpreting incremental samples to obtain more representative and reproducible data.
Topic(s): Incremental Sampling Methodology, Remediation Technologies, Sediments, Soil Background, Soils
