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Post Concentration


This value is always used when the site scale is chosen. Site scale calculates the average remaining concentrations over the site. Under these circumstance one must consider the amount of contamination left in each block or artificially placed there by a back fill process. Given certain values for the decision goal, certain choices for post remedial concentration may lead to impossible remedial designs. (For example, a site decision goal of 1 and a post remedial concentration of 10,000.) It is not necessary, however, that the post remedial value be less than the site decision goal. For example one may begin with a site average of 5 and a maximum block value of 10. Depending on how the rest of the block values are distributed, a post remediation value of 6 may successfully bring the site average down to 5. Clearly though, the post remediation value must be less than the maximum block value. Why don’t you use post remediation concentration in the block scale? There is no need to at this time. In the block scale method, the goal is to remediate the block to below the decision criteria. Clearly, if the post remediation value is greater than the goal, then the block goal will never be achieved. On the other hand, if the post remedial value is less than the decision goal, then the remedial design can succeed. There are no other options.