Formatted Title:

Identification of Beneficial Use of Sediment and Habitat Restoration Needs at Contaminated Great Lakes Coastal Areas

Background/Objectives:

USACE needs locations for beneficial use (BU) of dredged material. Aquatic sites impacted by chemical contamination that have been remediated often require additional restoration for ecological functions to be restored. In-water sediment remediation sites (whether marine or fresh water, conducted by various agencies under various authorities) typically result in a capped area or a physically stabilized (via in-situ stabilization [ISS]) area that confines any residual contaminants. These capped and stabilized areas do not support adequate habitat functions since the benthic environment has been degraded, first by chemical contamination and then by active remediation (ISS results in a hardened bottom that does not support a benthic ecosystem). Dredged material can be used beneficially as the basis to restore the aquatic ecosystem on top of the remediated area. Habitat uplift is one term used to describe this approach. The objective of this research project was to systematically identify locations and habitat needs where navigation dredged sediment could be used to create or restore near shore or wetland habitat (including coastal and tributary) in remediated Great Lakes areas where the remediation has left a waterway that lacks suitable habitat biodiversity (due to the removal of contaminated materials, capping, ISS and other remedial actions which remove or contain contaminants, but do not restore ecological function).

Approach/Activities:

The researchers have been working with regional and local stakeholders (federal and state agencies, non-governmental and community groups) to identify locations that would be suitable for the approach, and to screen these alternatives. A broad list of possible project sites was generated based on publicly available information from federal and state remediation program databases. These programs provide information on the status of remedial action sites. Sites within the Great Lakes and tributaries were the focus for an initial list of potential project sites, however the approach could be used across the nation. The initial criteria were to be a waterway (river, lake, coastal area) within the Great Lakes watershed, with identified sediment contamination issues that have been or are planned to be remediated.

A stepwise approach was used for a tiered screening evaluation framework as a logical progression to prioritize the original list of projects into a short list of specific locations where a proposed habitat restoration would likely be successful. Broad criteria included proximity to a federally maintained channel, proximity to sources of beneficial use material of sufficient quantity and quality, benefits provided, project implementability including the status of the remediation and logistical considerations, and project support including stakeholder willingness to implement habitat restoration and funding opportunities.

Results/Lessons Learned:

The initial compiled list of projects included over 50 sites across the U.S. Great Lakes. Project sites included Comprehensive Environmental Response, Compensation and Liability Act (Superfund), Area of Concern, Resource Conservation and Recovery Act, and state-led remediation projects. Projects from all Great Lakes states except Pennsylvania were included, and projects covered the U.S. portion of all five Great Lakes. Projects were screened into three categories: advance, re-evaluate in future, or not a viable candidate. Projects could be screened at any step of the rating process and updated as new information becomes available. The characteristics of highly ranked projects, the overall outcome, and the next steps toward project implementation will be presented.

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Burton Suedel