Regional Great Lakes Dredged Material Testing and Evaluation Manual: A Comprehensive Critique on Its Application

The Great Lakes Dredged Material Testing and Evaluation Manual (Manual) is formal guidance promulgated by a joint U.S. Environmental Protection Agency (USEPA)/U.S. Army Corps of Engineers (USACE) task group to provide protocols for the testing and assessment of dredged material proposed for discharge into United States (U.S.) waters of the Great Lakes, in accordance with the Guidelines of Section 404(b)(1) of the Clean Water Act (40 CFR 230.10). Founded on national guidance contained in the Evaluation of Dredged Material for Discharge in Waters of the U.S. - Testing Manual, it is a regional manual commissioned for the Great Lakes. Although the Manual was not finalized until 1998, the guidance contained therein has essentially been applied to Great Lakes dredged material since at least 1993. The protocols provide for a three to four-tiered system that utilizes existing environmental information, sediment and water chemistry, modeling and effects-based biological testing to ascertain the suitability of dredged material for disposal at open-water sites in the Great Lakes. Application of the guidance in the Manual to USACE dredging projects in the Great Lakes has met with reputable success and it has ensured that the open-water disposal of dredged material is appropriate and protective of the aquatic environment. Nonetheless, certain aspects concerning the application of the Manual may also be problematic, and specific cases are presented and evaluated to identify the potential need for clarification or improvement. These intricacies may be project-specific, protocol-oriented or speculative in nature, and have been grouped into five focus areas. First, sampling and testing, and utilizing the data from potentially non-representative disposal/reference areas, is discussed. Second, the elucidation and use of confounding or conflicting bioassay test results are addressed. Third, the use of the default biota-sediment accumulation factor (BSAF) in the theoretical bioaccumulation potential (TBP) model is evaluated. Fourth, the relevance and value of data generated from bioaccumulation tests for sediment metals is discussed, and some inconsistencies on the interpretation of bioaccumulation data are presented. Fifth, instances where States use other dredged material guidelines, policies and standards are discussed with respect to their association with the guidance contained in the Manual. In addition, the overall reception of the Manual by several State regulatory agencies is reviewed. Recommendations are offered on how to clarify or advance the Manual in these areas in order to make its application more effectual.