News and information for the worldwide dredging industry

Environment Canada Experts Discuss the Nation’s Disposal at Sea Protocols

Members of the environmental panel were, from left, Mark Dahl, Vicki DaSilva-Casimiro, Deborah
Austin, Monica Harvey, Suzanne Agius and Craig Vogt, moderator.

Members of the environmental panel were, from left, Mark Dahl, Vicki DaSilva-Casimiro, Deborah Austin, Monica Harvey, Suzanne Agius and Craig Vogt, moderator.

The environmental dredging panel at the Western Dredging Association (WEDA) annual meeting in Toronto comprised scientists and regulators from Environment Canada (EC), who discussed the scientific and regulatory framework in Canada for placement of dredged material at sea.

Entitled “Setting a Course: Future Directions of the Disposal at Sea Assessment Framework for Dredged Material in Canada,” the panel was organized by Craig Vogt, chair of the WEDA Environmental Commission.

Vicki DaSilva-Casimiro led off the discussion with an introduction to Canada’s regulatory framework. She is marine programs project manager, EC Quebec Region.

“Environment Canada is the department responsible for protecting the environment, conserving the country’s natural heritage, and providing weather and meteorological information to keep Canadians informed and safe. Canada is a Party to the London Protocol and London Convention (marine pollution prevention treaties) and is committed to preventing marine pollution through the implementation of a disposal prohibition, a permit system for certain types of disposal at sea, a site monitoring program and annual reporting,” she explained.

She and the other panel members referred often to the Canadian Environmental Protection Act, 1999 (CEPA), which provides a legislative and regulatory framework for complying with the nation’s London Protocol and London Convention obligations. Only wastes listed in CEPA can be considered for Disposal at Sea (DaS) permits, and the legislation outlines the steps necessary for obtaining a DaS permit. The assessment is in two tiers – Tier 1 focusing on chemical data and Tier 2 on biological data.

“This assessment framework could benefit from enhancements regarding the chemical and biological parameters that are assessed, the processes for routine versus high-risk applications,” she said, and other members of the panel expanded on this thought.

Monica Harvey, disposal at sea program scientist, presented “Growing, Adapting and Improving: Recommendations to Advance the Disposal at Sea Regulatory Framework and Assessment Processes.”

She explained that under the existing two tiered protocol, if all contaminant levels are below the chemical lower action levels in Tier 1, or if results pass the biological test requirements in Tier 2, the dredged material can be considered for unconfined open-water disposal, as it is considered to be of negligible risk to the environment. But Environment Canada is considering a more efficient tiered approach. The proposed changes are: the addition of a totally separate, streamlined assessment process for low risk applications, the expansion of the minimum list of chemicals of concern, the use of chemical rejection limits to quickly identify high risk sediments, the addition of a screening level bioassay in parallel with chemistry, the use of bioassays for sediments of intermediate quality and the addition of a comparative risk assessment for high risk applications.

Deborah Austin, marine protection advisor, National Capital Region, presented “Anatomy of a Decision I: Potential Regulatory Outcomes from Changes to Chemistry Protocols in the Canadian Disposal at Sea Program.” She explained the two-tiered approach, describing Tier 1 as determining sediment geophysical properties and concentrations of four regulated chemical constituents (Cd, Hg, PAH and PCB), and other chemicals of interest, based on lower action levels. Her paper reported on recommendations for changes to Tier 1 chemical protocols and further work to address other aspects of the framework.

Suzanne Agius, marine policy analyst, National Capital Region, expanded on Austin’s paper with “Anatomy of a Decision II: Potential Effectiveness of Changes to Tiered Sediment Assessment Protocols in the Canadian Disposal at Sea Program.” She spoke on an evaluation of how effectively various chemical/toxicological assessment protocols perform, based on outcomes using a database of paired chemical and biological sediment data.

“Adding chemical constituents to the chemical action list and a screening bioassay in Tier 1 both significantly enhance the effectiveness of Tier 1 in predicting Tier 2 toxicity, but at a cost of false positives, which trigger more extensive bio-assessment,” Agius said. Carefully designed mean hazard quotient approaches can be as effective as “one out/all out” rules, and the use of chemical screens in Tier 2 can be used to examine the possibility that sub-lethal toxicity assays may be responding to confounding factors, rather than chemistry.

“Anchor’s Aweigh: The Future of the Disposal at Sea Regulatory Framework in Canada” was Mark Dahl’s topic. He is with EC’s Atlantic Region.

Every year, millions of tons of sediment are assessed by Environment Canada and cleared for disposal at sea, he said. But in cases where dredged material is placed in the sea for purposes other than disposal, there is no formal assessment process. Conditions to mitigate effects are voluntary, and monitoring is not carried out following the placement of these materials at sea. Entities that carry out placement activities without seeking advice from Environment Canada could be subject to enforcement action if they are NOT for a purpose other than mere disposal, and/or cause marine pollution (as defined in CEPA, 1999).

Dahl explained that Environment Canada is considering a regulatory structure to cover these other types of placements. This would help to minimize the legal uncertainty associated with placements, saving time for both the regulator and proponent, and also ensure environmental protection for from all placement activities.

Vogt concluded the session by stating that he was very impressed with the breadth and depth of the scientific and technical analyses that are being conducted as the foundation for implementing the Environment Canada ocean disposal regulations and guidelines.

Edit Module