Conservation: Salvaging the Lakes

Of the Great Lakes, only Lake Erie so far has become so badly polluted that beaches have been closed and commercial fishing has nosedived. To salvage Lake Erie, the U.S. Government has embarked on a $3.9 billion program of pollution control, expects eventually to spend $100 billion to prevent the nation's other waterways from becoming foul. Great Lakes states are already preparing proposals, to be presented to Interior Secretary Udall by July 1, aimed at halting any new pollution.

Such action could scarcely come soon enough. Even if Great Lakes pollution ceased immediately and completely, Chemist Robert Rainey of Oak Ridge National Laboratory reports in a recent Science magazine article, it would still take the natural flow of water through the lakes a shockingly long time to purify them. Because they are relatively shallow, Lake Erie could purge 90% of its polluting wastes in about six years, Rainey calculates, and Lake Ontario in 20 years. But Lake Michigan would need 100 years to achieve the same degree of purity, and Lake Superior would not approach its pristine state until A.D. 2467.