Conscious Choice: Swim At Your Own Risk

July 1995

Swim At Your Own Risk

by Kristin Lauhn-Jensen

Whether or not you can enjoy swimming at the local beach this summer depends largely on where you live. Most beaches along the Great Lakes regularly close for at least a few days each summer due to elevated pollution levels. But "elevated" seems to mean different things in different states.

The amount of fecal coliform bacteria determines beach closings around the Great Lakes. Fecal coliform is transmitted through the fecal matter of humans and other animals. It is not, however, bacteria that make us sick. Fecal coliform is an indicator bacterium; higher counts of fecal bacteria indicate a greater amount of fecal matter in the water. This fecal matter potentially carries other bacteria, such as salmonella, shigella, or streptococci, that do cause illness in people. Illnesses commonly associated with exposure to these bacteria are stomach flu, fever, respiratory ailments, and skin irritations.

Both the U.S. and Illinois Environmental Protection Agencies advise that fecal coliform counts should not exceed 200 counts per 100 milliliters of water. (In the rest of this article, coliform counts should be read to indicate counts per 100 ml of water.) Only state Public Health department criteria are actually enforced, but most states around the Great Lakes follow the EPA guideline. The limits mean nothing, though, if counts are taken only once per summer. There is great irregularity in standards governing how = counts must be elevated before beaches are closed. Even EPA standards vary. Federal guidelines advise that less popular beaches require less monitoring, as fewer people are exposed to potential hazards than on crowded beaches.

The Illinois Department of Public Health enforces a relatively high limit of 500 counts. Only two consecutive tests exceeding this limit, however, are required to close a beach, and at least in the Chicago area, beaches are tested once a day in the summer.

If you will be vacationing in Michigan, you may want to enquire with local health departments as to whether a particular beach is monitored at all. Lisa Shields of the Delta County Environmental Health Department says that beaches in the Escabana area have not been monitored for fecal coliform since 1990, apparently due to insufficient workforce. In Ohio, beaches must be exceed legal limits in 5 consecutive tests before they are closed. Ohio does take the precaution of automatically closing beaches for a twenty-four period after heavy rains. This is because coliform counts generally rise after a rainfall, due to runoff washing ground pollutants into nearby waterways.

In New York, Buffalo’s Environmental Health department requires that five tests in a thirty-day period must exceed the limit before beaches are closed. Minnesota’s Duluth health department also tests four or five samples before closing a beach.

Wisconsin employs an entirely different test. The Environmental Health office in Milwaukee bases beach-closure on rainfall, not on the coliform count. The greater the rainfall, the longer the beaches remain closed. This policy, of course, is based on the assumption that only rainfall causes significant amounts of bacteria.

Our Canadian neighbors in Toronto provide for only 100 counts, but those counts are of E. coli, not fecal coliform. E. coli is also an indicator bacterium; but the Canadian government believes it indicates a more reliable connection to disease-causing bacteria than does fecal coliform. Should we be concerned about other pollutants in our swimming water? Last year, the Metropolitan Water Reclamation District of Greater Chicago found low but measurable amounts of chloroform, acetone, and DDE, a product that results from the breaking down of DDT, in Lake Michigan. There are no federal or state water quality standards for these toxins. So how much fecal coliform really does constitute a danger to human health? And should we be concerned about swimming in substances that are toxic to ingest, like pesticides, but for which there are no water quality standards? These questions seem difficult to resolve. Dr. Gary Brenniman, of the Environmental and Occupational Health Science department at the University of Illinois in Chicago’s School of Public Health, says that it is hard to study illness resulting from exposure to contaminated water because symptoms do not show up until two to three days after exposure. It is difficult to isolate swimmers from other factors in the intervening two days, factors that might themselves cause the illness. In addition, contact with water differs among swimmers, as some immerse themselves completely while others just wade. Thus, it is hard to establish a consistent test group.

Consider as well that limits may be lowered for other than just health reasons. Politicians eager to demonstrate their commitment to a cleaner environment may lower coliform limits as an easy but very public gesture. A more stringent standard would not increase beach closures if counts on the beach were in any case generally low.

Even among environmental organizations like the Lake Michigan Federation, concern today is mainly with drinking water quality and fish sampling. For beach-goers, the key to clean water seems to be in finding out for oneself what is going on at one’s beach of choice.

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