8.4.4 Limitations

When asked to identify the most significant challenges to broader implementation of ISM, survey respondents identified delineation of local areas of high concentration as the top difficulty, with the lack of regulatory acceptance at or near the top. In fact, regulators identified regulatory acceptance as the most important challenge, followed by collecting ISM samples for VOC analysis and determining the DU. By contrast, nonregulator respondents identified delineation of hot spots as the top difficulty, followed by regulatory acceptance and delineation of the extent of contamination.

Other limitations identified by respondents include a general lack of training/knowledge of ISM concepts and techniques in both the regulatory and consulting communities, difficulties in using ISM techniques on projects involving collection of subsurface samples, and comparing ISM data sets with historic discrete sampling results.