2005 Fairfax County Regional Science and Engineering Fair

The abstract below was written by the students. The Northern Virginia Soil and Water Conservation District made no editorial changes.

Abstract

The purpose of our experiment was to determine the positive filtration effects of our local wetland, Huntley Meadows, on its surrounding watershed. More specifically we wanted to test the presence of individual pollutants commonly used in communities in Huntley Meadows, versus water sources before and after the wetland. In a three week time period we tested six sources: Dogue Creek, Barnyard Run, a small creek before Huntley Meadows, Huntley Meadows Wetland, Jackson Abbott Wildlife Refuge, and the Potomac River, for 11 chemicals, and compared the concentration of each chemical in the six sources. We also tested tap water and distilled water as controls.

Ammonia, nitrogen, iron, nitrate, phosphorous, and silica were present in each of the sources, and a common trend occurred where a stronger concentration was found in the three sources prior to Huntley Meadows. Once the water sources fed into Huntley Meadows and the Jackson Abbott Wildlife Refuge, the concentrations of the chemicals became much less and almost nonexistent. However, the concentrations increased when water left the protected areas into the Potomac River. The pH of the water was slightly acidic before Huntley Meadows, was almost neutral in Huntley Meadows and Jackson Abbott, but became basic at the Potomac River. We found no traces of chlorine, chromium, copper, cyanide, or sulfide in any of the sources.

From our results, it can be determined that Huntley Meadows has a profound impact in filtering excess nutrients, pollutants, and contaminants in runoff, thus showing the significance of wetlands upon our community.