Researchers at the University of Missouri-Rolla are building a wetland near a mine and smelter plant in southeastern Missouri to help remove lead and other toxins from the water supply.

Wetlands are an effective way to trap and remove lead and other toxins from water because of the chemical reaction that occurs among the natural materials that make up a wetland, says Mark Fitch, associate professor of civil, architectural and environmental engineering at UMR.

The wetland forms something of a filter, letting the water seep through and leaving the lead, zinc and other toxins behind. A wetland constructed correctly may be effective for more than 30 years, Fitch says.

Based on UMR's research, the Doe Run Buick Resource Recycling facility in Boss, Mo. has designed a wetland the size of a football field. The recycling facility is a prime location for the man-made wetland because it will keep the chemicals released during the recycling process from getting into the water supply, Fitch says.

Fitch says the constructed wetland consists of 50% chip bark, 20% gravel, 15% sand, and a miscellaneous amount of straw, peat moss, sewage sludge and aged manure.

“The sewage and manure, however, does not cause the wetland to stink,” Fitch says. “It provides the bacteria needed to make the whole process work. This is a very inexpensive way of removing toxic components of wastewater, particularly mine water.”

Once the wetland construction is completed at the Doe Run Buick Recycling facility, Fitch and his team of researchers will put in sampling ports to monitor its effectiveness. From these results, Fitch says, they will be able to improve upon the man-made wetland.