![]() About half of the sediments dredged from Great Lakes harbors and channels are clean sand and silt than can be safely placed into the lakes, used to nourish beaches or for upland beneficial uses. The selection of the appropriate option for managing a dredged material is based on the type and level of contaminants present (if any), the volume of materials, local conditions, and environmental, social and economic factors. Treatment (applying one or more processes to remove or destroy contaminants) Sediments dredged from Great Lakes harbors and channels may be managed using one of the following methods: Another 1-2 million cubic yards of sediments are dredged from state, municipal and private harbors and marinas, as well as dredging for waterfront construction, bridge construction and repairs, clearing water supply intakes, and environmental restoration. Every year, the Corps of Engineers dredges about 4 million cubic yards of sediments from 15-25 of these harbors. ![]() There are over a hundred federal harbors and channels in the Great Lakes. ![]() “Restrictions on dredging activities” is one of the fourteen beneficial use impairments identified in the Agreement. Dredging of sediment deposits is required to maintain channels at safe depths for navigation.Ĭontaminated bottom sediments are present in many of the federal navigation projects in the Great Lakes and every one of the Areas of Concern designated under the Great Lakes Water Quality Agreement. ![]() As sediments accumulate, the depths of channels used by commercial ships and recreational boaters are reduced. Sediments that accumulate in the bottom of river channels, harbors and lakes are the product of soil erosion from lands throughout the watershed and erosion of streambanks. ![]()
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