Man-made wetlands aid waste disposal.

In 1991, manure runoff from a dairy farm dumped nitrogen and phosphates into Appleman Lake, a popular local fishing site in LaGrange County, Ind. The extra nutrients in the runoff allowed aquatic plants in the lake to thrive so much that they threatened to turn the lake into "a big green mess." Today, though, thanks to a Purdue University-developed man-made wetland, water running off the farm is as clean as the water in the lake. Moreover, the livestock area that was once a source of pollution has produced two broods of mallard ducklings.

"This is a win-win situation for both the farmer and the environmentalists," maintains Stephen Lovejoy, associate professor of agricultural economics. Farmers have tended to view wetlands as potential cropland that should be drained; environmentalists view them as endangered habitats for a variety of wildlife.

"Wetlands are like Mother Natures' kidneys," indicates Paul DuBowy, assistant professor of wildlife ecology. "We've seen a 40% to 60% reduction in nitrates and phosphates at the LaGrange site. We'll see even better reduction rates once the wetland gets fully established." The project consists of three long, shallow wetlands, or cells, each 20 feet wide and 150 feet long. Individual cells allow the researchers to adjust the size of the wetland to compensate for varying nutrient levels. Construction on the first wetlands was begun in October, 1991...