Biology Class Goes to the Stream

Abstract

C ONSIDERATION OF ENVIRONMENTAL PROBLEMS is an indispensable part of any modern biology course. Giving students an opportunity to actually assess some aspect of environmental pollution is desirable, and if this assessment applies to the school community it becomes even more relevant. My own search for a worthwhile environmental project for my second-year biology students led to the sanitation department in Danville, Ind. Dick Wicker, Danville's sanitarian, agreed to assist the class in the project by conducting a tour of the town's sewage treatment plant and the waterworks on two separate field trips. He explained the basic operation of each plant to the class and also described some of the major problems which the town faces in waste water treatment. Danville's sewage treatment plant is located on a small stream into which it discharges its waste effluent. At the present time the Danville treatment plant carries out secondary treatment only, that is, only the vast majority of suspended organic wastes and harmful bacteria are removed. Future plans call for tertiary treatment-the removal of nitrates and phosphates. Danville's waterworks is located upstream from the sewage treatment plant, but the town's water supply comes from a deep well and not from the stream. However, the water treatment plant does discharge into the stream quantities of iron removed from the drinking water.