DECIDING WHEN TO INTERVENE

There is a consensus among diverse sectors in the Great Lakes Basin (e.g., government, industry, non-governmental organizations, Remedial Action Plan groups) that contaminated sediment is an important element leading to many of the impairments to beneficial uses of the Great Lakes. All 42 Great Lakes Areas of Concern have contaminated sediment based on application of chemical guidelines. This universal obstacle to environmental recovery in Areas of Concern can potentially pose a challenge to restoring 11 of the 14 beneficial use impairments identified in the Great Lakes Water Quality Agreement (SedPAC 1997).

For Remedial Action Plans (RAPs), sediment management decisions need to be made bearing in mind the relationship between contaminated sediment and restoration of beneficial uses. This goes far beyond setting a numerical chemical cleanup criteria, as these are not based on the need to fully restore beneficial uses. What is needed is a pragmatic decision-making framework that leads to the selection of ecosystem and cost-effective options for management of contaminated sediment.

The Water Quality Board (WQB) has called for a step-wise and incremental approach to management of contaminated sediment and restoration of beneficial uses (SedPAC 1997). Sediment remediation, removal of a mass of contaminants, and reduction of risk are important indicators of incremental progress. The ultimate success of sediment management activities will be judged upon restoration of beneficial uses (e.g., elimination of fish consumption advisories, restoration of fish and wildlife populations, restoration of benthos).

Bioassessment frameworks have evolved substantially recently, and in many cases large data sets have the required elements for developing a sediment management strategy. Equally important to the collection of data, however, is that sufficient attention be placed on thorough and comprehensive interpretation of the data. By employing scientifically sound methods of data interpretation, the information from an intensive sediment assessment can finally be integrated to make a decision to intervene (i.e., remediate contaminated sediment) or pursue source control and natural recovery as the preferred remedial option.

SedPAC's primary intent with this document is to share advances in data interpretation tools regarding sediment management decision-making with RAP practitioners. Presently, a great deal of data have been collected on the physical, chemical, and biological elements that modify contaminant bioavailability and ecological effects. The literature contained herein and cited below can help guide RAP practitioners through a transparent use restoration decision-making process.

In addition to this review of data interpretation tools, SedPAC recognizes that the International Joint Commission (IJC) can offer more assistance in the efforts to overcome obstacles to sediment management. Specifically, SedPAC recommends:

• that the Commission recommends to the Parties and Jurisdictions that they develop and reach agreement on methods or programs to predict and measure successful ecological recovery in Areas of Concern (e.g., ecological benefit forecasting, monitoring and surveillance programs to measure use restoration); and
• that the Commission recommends to the Parties and Jurisdictions that they establish procedures for consistent data collection and interpretation across Areas of Concern, recognizing the importance of site specificity in applying methodologies and tools.

The Commissioners also have an important role to fulfill in overcoming obstacles to sediment management for beneficial use restoration. SedPAC recommends that Commissioners:

• develop and implement an IJC public outreach strategy to help make contaminated sediment management a priority throughout the basin.

SedPAC notes that there are currently few, if any, simple or proven methods to predict recovery of use impairments based on sediment cleanup. More research is needed to quantify the relationships between contaminated sediment and known use impairments. The concept of ecological benefit forecasting (i.e., predicting ecological benefits and restoration of beneficial uses) is an important management need, which if accomplished, would be a substantial step forward.

Finally, deciding when to intervene is embedded with multiple elements. Data interpretation tools and techniques are a central element in developing the sediment management strategy. This report is one in a series that will explore a number of aspects affecting sediment management. Other aspects involve what is and is not known about linking sediment cleanup to ecological recovery and restoration of beneficial uses, as well as economic benefits that may accrue from effective management of contaminated sediment.