16. Lake Superior Lake Michigan Lake Huron Lake Erie Lake Ontario IN CANADA CANADA CANADA WISCONSIN OHIO INDIANA ILLINIOS PENNSYLVANIA NEW YORK MICHIGAN MINNESOTA Grand Marias Two Harbors Duluth Superior Ashland Ontonagon Keweenaw Waterway Presque Isle Marquette Grand Marias St. Marys River Channel in Straits of Mackinac Grays Reef Little Bay de Noc Menominee Green Bay Kewaunee Port Washington Milwaukee Kenosha Manitowoc Sheboygan Waukegan Chicago River & Harbor Calumet Indiana Harbor Burns Waterway Harbor St. Joseph Harbor Holland Grand Haven Muskegon Harbor Ludington Manistee Frankfort Charlevoix Cheboygan Alpena Saginaw Harbor Beach Monroe Channels in Lake St. Clair St. Clair River Detroit River Rouge River Toledo Sandusky Harbor Huron Lorain Cleveland Fairport Ashtabula Conneaut Erie Dunkirk Buffalo Harbor Rochester Harbor Oswego Ogdenburg 800K 100K – 250K 50K – 95K <50K ANNUAL DREDGING REQUIREMENT (CY) DREDGED MATERIAL MANAGEMENT STATUS Critical – Dredged Material Management issues could severely restrict channel availability within 5 years Pressing – Dredged Material Management issues could severely restrict channel availability within 10 years. No pressing issues within next 10 years; continue to work on long range planning such as DMMPs.
17. Turbid or muddy water may act as the incubator for algae blooms. The picture on the left shows the plume of sediment coming from the Maumee River on August 26, 2008—a breezy day when the water column was mixing. On the right, in a picture taken on September 3, 2008, you can see that the bloom had grown over the plume.
18.
19.
20.
21.
22.
Notas do Editor
A Report to Congress prepared by the Corps and USEPA in 2005 concluded that the overall impacts of CDFs on the Great Lakes were significantly positive because these facilities enabled the removal and containment of over 90 million cubic yards of contaminated sediments from rivers and harbors, decreasing their exposure to fish and wildlife, and eliminating the likelihood that the contaminants would be washed into the Lake and spread over an even greater area. Update the 90M cy to 2008? Much of the dredged material placed in Great Lakes CDFs is enriched with plant nutrients (nitrogen and phosphorous). As CDFs are filled, dense vegetation has rapidly covered exposed dredged material. Although the proportion of clean sediments is increasing due to the success of decades of environmental efforts, we are at or near capacity at many CDFs. The Corps of Engineers is striving to prolong the service life of our CDFs by emphasizing beneficial use or open lake disposal of suitable characterized dredged material, extending CDF life through fill management activities and dredged material recycling. The composition of sediments in the upper Great Lakes is very sandy and therefore can be highly desired for beach fill and other beneficial uses; the composition of sediments in Lake Erie is more silty and is therefore less desirable for beneficial use. Also, while open lake disposal is generally not favored by the Ohio EPA, its concerns seem to be heightened in the very shallow western third of Lake Erie. At a number of harbors in Michigan and Wisconsin, near-shore placement for beach nourishment and upland placement (placement in farm fields, etc.) are often cost competitive with open-water disposal and are the preferred methods of disposal of dredged material.
