
	Chapter 2


	Introduction

	Policy Response

	Scale of the Restoration Challenge

	The Need for a Restoration Strategy

	Conclusion

	Recommendations

Scale of the Restoration Challenge

Vast deposits of pollutants lie within contaminated sediment, threatening for decades to come the health of Great Lakes fish and wildlife and humans. Remediating contamination remains a major challenge requiring significant up-front investments.

Contaminated sediment often does not lie in stable, easily identified and relatively easy-to-cleanup "hot spots". Sediment containing contaminants are often poorly controlled, unstable systems containing large volumes of moderately contaminated material.¹⁰ Contaminated sediment in Areas of Concern may be viewed as only a local problem. If they disperse, however, the contaminants can also affect the offshore regions and open waters of the Great Lakes, making remediation extremely difficult, and their toxic effects remain. Polluters responsible for the original contamination often no longer exist. Where polluters do exist, litigation often prolongs remediation. The Parties must take action more swiftly to prevent the inevitable and irreversible dispersal of contaminants.

Since existing programs have been insufficient for clean-up, governments must allocate adequate funds to clean up contaminated sediment and remove the threat to human health before sediment is too dispersed to remediate. In those cases where perpetrators can be found, some means must follow by which they pay for the problems they have caused. The Commission strongly recommends that the Parties develop strategies for prioritizing sites for remediation, and move forthrightly ahead.

To date, the magnitude of the contaminated sediment problem in Areas of Concern and its relationship to contamination of open lake waters remains poorly quantified. Sediment contaminated with PCBs and mercury is of particular concern.¹¹ Natural degradation of highly chlorinated PCBs is limited and occurs very slowly.¹²

Preliminary estimates of PCBs in the sediment of lakes Superior, Michigan and Ontario are 3,300 kg, 87,000 kg and 115,000 kg, respectively.¹³ The Lake Michigan estimate does not include the quantities in Green Bay, which have been calculated separately at 68,000 kg. Large quantities of contaminated sediment at sites such as the Fox River and Lower Green Bay can also serve as indirect sources of PCBs molecules of PCBs can be transferred first to water, then into the air (volatilized) and back into the open lake by prevailing winds.¹⁴ The relative significance of PCB loads contributed by the atmospheric pathway varies for each lake basin. Estimates for Lake Michigan indicate that 3,200 kg per year reach the lake through the air.¹⁵

Sediment remediation remains a large-scale, high-cost problem requiring a strategic long-term solution. While the magnitude of the problem is greater in the United States than in Canada, using the most modest estimates, it would cost billions of dollars for thorough remediation.

Large-scale remediation efforts signal a commitment to protect the health of present and future generations and to restore the integrity of the Great Lakes. Reducing the body burdens of persistent toxic substances in fish populations will achieve the goal of protecting human health from this consumption pathway and will assist in the recovery of fish and wildlife populations. Based on positive restoration results in areas such as Gill Creek (a tributary of the Niagara River), Black River and Waukegan Harbor, remedial actions can be expected to stimulate improvements in ecosystem health in comparable Areas of Concern.

Since signing the Great Lakes Water Quality Agreement, governments have taken action to curb chemical inputs, particularly from industrial point sources discharging directly to the lakes. The lakes responded, and several chemicals in fish and wildlife declined. Less aggressive action has been taken to cut atmospheric emissions, and for some lakes, the inputs of substances such as mercury and PCBs are dominated by atmospheric deposition. The amount associated with sediment, however, remains the singular largest pool requiring attention, to prevent further harm to humans, fish and wildlife. For example, in Lake Michigan the amount of PCB in sediment is two to three orders of magnitude greater than the annual inputs from air and tributaries, respectively.

In Wisconsin, the Lower Fox River offers an example of the scale of the budgetary and management challenge being met at one Area of Concern. Achievement of a current goal to remove 5.5 million cubic meters of sediment, along with approximately 30,000 kilograms of PCBs, within the planned time frame of five to seven years is an ambitious undertaking requiring removal at a rate of close to one million cubic meters per year.¹⁶ This may not be the end of the process.

Across the Areas of Concern lie an estimated 95 million cubic meters of material thought to be chemically contaminated at some level. Even if further biological testing shows that only a small percentage of this total must be removed, cleanup actions would still require a very large long-term commitment of time and resources. While source control and natural attenuation (or natural recovery) may be helpful in some situations, large-scale problems clearly require large-scale investments.