LIST OF FIGURES

Figure 1-1 ISM flowchart
Figure 1-2 Sampling designs
Figure 1-3 Key terms
Figure 2-1 Heterogeneous nature of contaminants in soil leading to decision errors
Figure 2-2 Grain sizes ranging from 2 to 0.016 mm
Figure 2-3 Electron microscope photograph of the structure of smectite clay particles
Figure 2-4 Illustration of smectite clay plates and interstitial cation binding with dibenzo-p-dioxin
Figure 2-5 A single square foot area of surface soil contains 36 possible 2-inch diameter core sample locations
Figure 2-6 Observed short-scale heterogeneity with co-located uranium sample results
Figure 2-7 Process of extrapolation analyte sample results to soil concentrations
Figure 2-8 Variability among results of laboratory subsample duplicates measures within-sample heterogeneity
Figure 2-9 Smaller analytical masses contribute to high data variability
Figure 2-10 Illustration of the effects of sample mass on representativeness of the population
Figure 2-11 Depiction of grouping (A) and segregation (B) of particles
Figure 2-12 Illustration of the effects of sampling device design on particle size in a sample
Figure 2-13 Vertical view of sampling device that minimize EE
Figure 2-14 Increment DE and EE from sampling device selection
Figure 2-15 Examples of distribution generated by plotting concentration data vs. frequency (i.e., probability) of observation
Figure 3-1 Pictorial CSM
Figure 3-2 Decision units and sampling units
Figure 3-3 Examples of potential exposure area DUs
Figure 3-4 Exposure area DUs designated for a residential house lot
Figure 3-5 Source area DU in a suspected release area
Figure 3-6 Designation of perimeter DUs around a source area DU
Figure 3-7 One-meter vertical resolution DUs selected to help isolated heavily contaminated soil from less contaminated soil and assist in evaluation of remedial alternatives
Figure 3-8 A hypothetical investigation of series of stacked source area DUs using borings
Figure 3-9 An example of a subsurface DU for contaminated soil overlain by clean soil that is not accessible by excavation
Figure 3-10 Example of stockpile DUs
Figure 3-11 Floor and two sidewall DUs for an excavation site
Figure 4-1 ISM decision tree
Figure 4-2 Examples of the probability and magnitude of underestimation of the mean from a single ISM sample
Figure 4-3 Dispersion of means from ISM (based on n=30 increments) applied to a lognormal distribution (mean = 100) with CVs ranging from 0.5 to 3.03
Figure 4-4 Histogram of calculated Chebyshev UCL values using 5,000 trials of a lognormal distribution (mean=100, SD=200), 30 increments and 3 replicates
Figure 4-5 Range of overestimation (RPDA) and underestimation (RPDB) of 95% UCLs using Chebysehv and Student’s-t calculation methods for ISM simulation with lognormal distributions (CV=1 and CV=4), 30 increments and two to seven replicates
Figure 4-6 Four possible relationships between bias and precision
Figure 4-7 Systematic random sampling/systematic grid sampling with a random start (Serpentine)
Figure 4-8 Random sampling within grids
Figure 4-9 Simple random sampling within the entire DU
Figure 5-1 Field sampling implementation flowchart
Figure 5-2a Examples of coring devices for non-volatile soil increment collection
Figure 5-2b Example of a drill core bit sampling tool for non-volatile soil increment collection
Figure 5-3 Estimated sample mass based on number of increments for set increment and substrate density
Figure 5-4 Example DUs from an industrial (A), residential (B), and agricultural (C) sites
Figure 5-5 Illustrations of systematic random incremental sampling pattern used for collecting samples in square (A) and circular areas (B)
Figure 5-6 Schematic of a procedure to collect an ISM profile sample where two depths have been selected
Figure 5-7 Example of removing a wedge from the entire length of a soil core
Figure 5-8 Example of “core slice” sample
Figure 5-9 Examples of rectangular and flat-bottom sampling tools
Figure 5-10 Example of subsample being collected in the field
Figure 5-11 Bottles containing methanol and 44 five-gram plugs of soil
Figure 5-12 Examples of coring devices for VOC soil increment collection
Figure 5-13 Example of sample increments being collected and added to a bottle containing methanol for preserving VOC samples
Figure 5-14 Example of methanol aliquots from individual five-gram field preserved increments being compiled in the laboratory
Figure 6-1 Sample processing and analysis flow chart
Figure 6-2 Example of wet sieving soil on as an "as received” basis
Figure 6-3 Example of 2-D Japanese slabcake incremental subsampling on dried and sieved soil
Figure 6-4 Example of 2-D Japanese slabcake incremental subsampling on wet sieved, “as received” soil
Figure 7-1 Dot plot comparison of background (reference area) and site ISM results
Figure 8-1 Distribution of survey respondents (n=263).
Figure 8-2 Survey response of ISM sampling in land use type by program
Figure 8-3 Survey responses identifying the objectives of ISM sampling
Figure 8-4 Survey responses of the ISM media applications
Figure 8-5 Survey responses of states where the organization has participated in ISM
Figure 8-6 Survey responses of ISM sampling participation per land use type
Figure 8-7 Survey responses of the statement: “ISM is ineffective because it cannot identify specific areas of high concentration”
Figure 8-8 Survey responses of the statement: “incremental sampling cannot be used for risk assessment because it does not address variability”
Figure 8-9 Survey responses of the statement: “contaminant concentration depends on the amount of soil sample”
Figure 8-10 Survey responses of the statement: “ISM is generally more expensive than conventional discrete sampling”
Figure 8-11 Survey responses of the statement: “Incremental samples commonly require additional laboratory sample preparation”