Advancing its commitment to supporting a comprehensive federal services program, Merit Laboratories has expanded its DoD ELAP accreditation to include Incremental Sampling Methodology (ISM) sample preparation.
Understanding the Value of ISM
Incremental Sampling Methodology (ISM) is a statistically based sampling approach used by the U.S. Department of Defense (DoD) and other regulatory agencies to evaluate soil contamination with greater representativeness and reduced sampling uncertainty compared to traditional discrete grab sampling methods.
In ISM, a "Decision Unit" (DU) is defined as a specific area or volume of soil requiring characterization. Environmental professionals collect numerous systematic and evenly distributed soil increments, typically 30 to 100 samples, throughout the DU. These increments are combined and processed into a single representative sample for laboratory analysis.
By averaging contaminant concentrations across the entire DU, ISM helps reduce the effects of small-scale soil heterogeneity and localized concentration variability. This approach can improve confidence in site characterization data and support more informed remedial decision-making, particularly at complex sites where contaminant distribution is uneven.
Where ISM Is Making the Greatest Impact
* Military installations
* Brownfield redevelopment
* Industrial facilities
* Munitions response
* PFAS investigation and remediation
Merit Laboratories maintains full DoD ELAP accreditation and holds both Small Business Enterprise (SBE) and Woman-Owned Business Enterprise (WBE) designations. With large-scale testing capacity and national reach, we support PFAS analysis across a wide range of matrices—including drinking water, groundwater, soil, wastewater, biosolids, and sludge.