Assessment of Sampling Error Associated with Collection and Analysis of SoilSamples at Explosives-Contaminated Sites

摘要

This study is an assessment of short-range heterogeneity in contaminantconcentrations within surface soils at explosives-contaminated sites. Intensive sampling was conducted over short distances. Discrete and composite samples were analyzed by both on-site colorimetric methods and standard laboratory protocols. Three locations were sampled at each of three installations and the results used to estimate the relative contributions of analytical error and sampling error to the total uncertainty. The major contaminant at seven of the nine sampling locations was TNT. DNT and ammonium picrate were the contaminants present at the highest concentration in the other two locations. For four sampling locations, short-range concentration variations were modest and analyte distribution was sufficiently Gaussian to apply normal distribution statistics to fractionate the total error variances. The other five sampling locations had enormous short-range heterogeneity and sampling error overwhelmed analytical error. To improve the quality of site characterization data, emphasis should be placed on reducing sampling error by the use of composite sampling strategies.