2006 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 this experiment was to discover how acid rain and other environmental factors affect an aquatic ecosystem's pH, and in particular Bright Pond in Reston, VA. We hypothesized that with the addition of rain-water, the pH of Bright Pond would decrease. To test this hypothesis, on a daily basis, over the period of two months, data were collected from Bright Pond in four different locations. These data included measurements of water pH and water temperature. Rain pH and rainfall amount (mm) were also directly measured. In addition air temperature, wind speed and wind direction were recorded from weather.com. We found that in general rain did not appear to have any major affect on the pH of the lake, despite the fact that the pH of the rain was significantly more acidic than Bright Pond. Our hypothesis was thus proved incorrect. Evidence pointed towards air and water temperature to be the major factors in effecting Bright Pond’s pH. We conjecture that this is due to the fact that when the pond gets colder, fewer aquatic plants such as algae are living in the lake. These plants produce oxygen during photosynthesis, which has been shown to raise the pH of water. This could be the basis for a future research project.