Lake Michigan environmental survey : final report / [edited] by John C. Ayers.

1.2 million acres. DDT was applied to about 150,000 acres and accounted for
511,000 pounds.
The State of Wisconsin estimates that in its segment of the Lake Michigan
drainage basin approximately 150,000 acres of farm lands received 500,000
pounds of technical insecticides in 1967. Of this 86,600 pounds was DDT,
4,200 pounds was dieldrin, 103,800 pounds was chlordane, and 28,000 pounds was
toxaphene. Most of the remainder was composed of non-persistent insecticides."
MANUFACTURING-INDUSTRIAL WASTES
In our experience, this group does not fall into Dr. Mount's (above) categorization that fragmentary figures are available for some areas and for some
(wastes). We find in FWPCA publications actual lists, by states, of major industries with their flows of waste discharges and notes as to the compositions
of their wastes BUT NO INDICATIONS OF THE ACTUAL QUANTITIES OF WASTE MATERIALS
DELIVERED TO LAKE MICHIGAN VIA INDUSTRIAL WASTE. These figures may exist but
we have been unable to locate them. It is possible that lack of adequate
analyses of wastes does not permit the derivation of the total input that we
wish to have.
SEWAGE WASTES
There are lists, by states, of communities (down to miniscule size) and
of the quantities of waste-water that they discharge. Biological oxygen demand
(BOD) figures are relatively easily obtained, but generally nothing else is to
be found. There must be average values of solutes in sewage, by which discharges of waste-water could be multiplied to yield probable summations of
materials delivered to the lake via the sewage route. We have found such
figures for Lake Erie (Table 4-11, p. 63. "Lake Erie Report. A Plan for Water
Pollution Control." U. S. Dept. Interior, FWPCA, Great Lakes Region, Chicago,
Illinois) but to our present knowledge none exist for Lake Michigan.
AGRICULTURAL RUNOFF
Our findings in this category have been zero for Lake Michigan, yet the
fact that they have been produced for Lake Erie (reference above) indicates
that attention has been paid to this category of information. While we do not
think so, we may have missed a report on these findings.

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