Ecological-Based Clean-up Goals

The purpose of this report is to derive sediment clean-up numbers for appropriate ecological resources using existing data. The ecological resource that was deemed appropriate was defined as the assessment endpoint: functioning benthic invertebrate communities. Proposed clean up goals (PCUGs) were derived from a large database of sediment data that included the Indiana Harbor Area. The ranges of PCUGs are presented in Table 2.

The PCUGs are values that can be used as target goals for clean up activities. The lower number of a given PCUG range is the concentration below which no adverse effects would be expected. Therefore, cleaning up to below that number should result in no adverse effects. This is shown with the "less than" sign. The higher number of the PCUG range is the concentration above which there is a 50% chance that adverse effects would occur. The concentrations between the lower and higher values are unknown areas, where the occurrence or lack of occurrence of adverse effects in this range cannot be predicted.

There are uncertainties associated with the derivation and use of these PCUGs. While these uncertainties can not be quantified at this time using available data, this does not mean that the PCUGs cannot be used as targets for removal actions at this site.

This memo discusses the basis tor the ecologically-protective soil PCB clean up goals (CUGs) for terrestrial wildlife in the recreational use areas in the floodplain of the Little Mississinewa River (LMR), and a revised analysis of the effectiveness of various alternative remedial action levels (RALs) in reducing ecological risks in the floodplaia