The Effects Of Dredging On The Chemical Characteristics Of The Grand River

During spring 1977, water was sampled in the Grand River, which runs through the State of Michigan, to estimate the increased loads of polluting and enriching substances caused by dredging the river channel near its mouth at Lake Michigan. Results indicate that sedimentary material disturbed during the dredging process is carries out to the lake. On an annual basis, the increase in loading is approximately 1 percent for all variables measured; however, during the period of dredging (about 1 week), the increases are approximately 30 percent. The effects of these events on the nearshore ecology are not known at present.