The effects of possible changes to the Canadian two tiered assessment framework for dredged material based on outcomes of the 2006 Contaminated Dredged Material Management Decisions Workshop (CDMMD) are evaluated. Expanding on the “data mining” approach described in Apitz and Agius, 2013, which focused solely on chemical lines of evidence, the efficacy of Tier 1 approaches (increases to the number of chemical analytes, use of mean hazard quotients and the use of a screening bioassay) in predicting toxicity are evaluated. Results suggest value in additional work to evaluate the following areas: a) further expanding minimum chemical requirements, b) using more advanced approaches for chemical interpretation, and c) using a screening level bioassay (e.g. Canadian solid-phase photo-luminescent bacteria test) to determine whether it would complement Tier 1 chemistry as well as or better than the solvent-based MicrotoxTM test method evaluated in this study. This article is protected by copyright. All rights reserved
