Environment Canada's Disposal at Sea Programme hosted the Contaminated Dredged Material Management Decisions Workshop in Montreal, Quebec, Canada, on 28-30 November 2006. The workshop brought together over 50 sediment assessment and management experts from academic, industrial, and regulatory backgrounds and charged them with drafting a potential framework to assess contaminated dredged materials and compare the risks of various disposal alternatives. This article summarizes the recommendations made during the workshop concerning the development of sediment assessment tools, the interpretation of these tools, and the essential attributes of a comparative risk assessment process. The major outcomes of the workshop include a strong recommendation to develop a national dredging or sediment management strategy, a potential decision-making framework for the assessment of dredged materials and comparative risk assessment of disposal options, and the expansion of minimum sediment characterization requirements for nonroutine disposal permit applications.

A sediment quality triad approach was used to evaluate Environment Canada's battery of marine bioassays and the proposed pass/fail criteria along a metals gradient in Belledune Harbour, New Brunswick, Canada. Most assays performed consistently, but certain tests provided less response than expected at the more contaminated stations (amphipod survival and light reduction in photoluminescent bacteria tests passed according to proposed pass/fail criteria). Echinoid fertilization tests were quite sensitive. Bioaccumulation of lead and benthic community structure were related to bulk sediment values (at α = 0.1). Test interpretation criteria appear reasonable, but as the response rate was low in certain tests, further assessment is recommended. With respect to species suitability, only the clam Macoma balthica used in the bioaccumulation test was thought to be less than optimal for routine use on a large scale because of practical handling and cost considerations. Canadian draft Interim Sediment Quality Guidelines, which the Disposal at Sea Program may use for screening purposes in a tiered testing approach, were used in this study as the chemical benchmarks to select test stations on the basis of the relative probability of effects. Guidelines at the threshold effects level (TEL) performed well in the study as levels below which unacceptable biological effects were unlikely to occur. The ratio of simultaneously extractable metals to acid volatile sulfides was also used in addition to the guideline levels to help explain responses (or lack thereof) along the gradient. Each of the chemical approaches was useful in the prediction/explanation of some but not all of the responses seen in the toxicity and/or benthic community results.

Abstract-A sediment quality triad approach was used to evaluate Environment Canada's battery of marine bioassays and the proposed pass/fail criteria along a metals gradient in Belledune Harbour, New Brunswick, Canada. Most assays performed consistently, but certain tests provided less response than expected at the more contaminated stations (amphipod survival and light reduction in photoluminescent bacteria tests passed according to proposed pass/fail criteria). Echinoid fertilization tests were quite sensitive. Bioaccumulation of lead and benthic community structure were related to bulk sediment values (at ␣ ϭ 0.1). Test interpretation criteria appear reasonable, but as the response rate was low in certain tests, further assessment is recommended. With respect to species suitability, only the clam Macoma balthica used in the bioaccumulation test was thought to be less than optimal for routine use on a large scale because of practical handling and cost considerations. Canadian draft Interim Sediment Quality Guidelines, which the Disposal at Sea Program may use for screening purposes in a tiered testing approach, were used in this study as the chemical benchmarks to select test stations on the basis of the relative probability of effects. Guidelines at the threshold effects level (TEL) performed well in the study as levels below which unacceptable biological effects were unlikely to occur. The ratio of simultaneously extractable metals to acid volatile sulfides was also used in addition to the guideline levels to help explain responses (or lack thereof) along the gradient. Each of the chemical approaches was useful in the prediction/explanation of some but not all of the responses seen in the toxicity and/or benthic community results.

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Environment Canada's Disposal at Sea Programme hosted the Contaminated Dredged Material Management Decisions Workshop in Montreal, Quebec, Canada, on 28-30 November 2006. The workshop brought together over 50 sediment assessment and management experts from academic, industrial, and regulatory backgrounds and charged them with drafting a potential framework to assess contaminated dredged materials and compare the risks of various disposal alternatives. This article summarizes the recommendations made during the workshop concerning the development of sediment assessment tools, the interpretation of these tools, and the essential attributes of a comparative risk assessment process. The major outcomes of the workshop include a strong recommendation to develop a national dredging or sediment management strategy, a potential decision-making framework for the assessment of dredged materials and comparative risk assessment of disposal options, and the expansion of minimum sediment characterization requirements for nonroutine disposal permit applications.