A.6.5 Homogeneity

There seems to be some confusion about the homogeneity of a DU. In practice, it is not likely to encounter homogeneous environmental DUs; however, for clarification sake, this concept is discussed in some detail here. To illustrate the differences in the various DUs considered in this appendix (including other sections of the appendix), two types of homogeneities are described: a DU can be homogeneous with respect to (a) the bulk material particulates and (b) contaminant concentration present in the bulk material.