Description of Work The study will be implemented in two phases due to logistical constraints and the need to incorporate methods developed (and findings) from a comparable investigation underway in another AOC. The first phase will consist of site selection, methods refinement, work-plan development, subcontract assembly, site reconnaissance, and sediment collection which will be done mainly during FY2013. The second phase will consist of macroinvertebrate identification, sediment toxicity testing, data analysis and interpretation, and report preparation and review mainly during FY2014. In brief, we will generate bed sediment toxicity and benthic community data needed to test two related hypotheses that address the two criteria for [...]