Spotlight on Research: Researchers Find Simple Solution to Water Quality Problem
Posted: November 5, 2002 at 1:00 am, Last Updated: November 30, -0001 at 12:00 am
By Lynn Burke
Clarke County, Va., was concerned with its water supply, so it tapped into George Mason’s Environmental Science and Policy (ESP) Department for help. Chris Jones, department chair; ESP former graduate student LeAnne Astin; and current graduate student Ryan Hansen have completed three years of work to help the rural county, located in the Shenandoah Valley, decrease bacterial contamination in the streams that fuel the aquifer from which it draws its water supply.
The area is rich in limestone, and water that seeps through the ground dissolves the limestone, creating a network of underground channels and caves that provides much of the county’s water storage and springs. A great deal of interchange takes place among the streams, the springs, and the groundwater supply, so pollutants deposited on the ground can sink in and reach the water supply fairly quickly, says Jones. The county was having a problem with pathogenic bacteria, basically Escherichia coli, getting into the streams and worried that the bacteria would also get into the springs and the groundwater.
One of the things Jones and his team investigated was the streams’ benthic community (that is, the insect larvae and macroinvertebrates that inhabit the streams naturally), which acts as an indicator of the stream’s health. The team went to various sites and sampled the streams’ insect population. During the study, fencing was installed to keep cattle out of the stream. Sampling was repeated after the fencing was in place.
The researchers found that in areas of the stream now inaccessible to cattle, the benthic community was much healthier, with more types and species of aquatic insects and other macroinvertebrates present. “We felt that was because not only was the habitat more conducive in the sense that cows weren’t tromping around, breaking down vegetation on the banks and stirring up the bottom, but there was less direct pollution from fecal material–nitrogen, phosphorus, and that sort of thing–directly from the cattle’s waste,” says Jones.
“The study illustrates that a relatively simple management practice can have a major beneficial effect on waterways,” he says.