2003 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

Our main water supply comes from the Potomac River. The Potomac River is threatened by many kinds of pollution. The most common cause of domestic pollution is sewage drainage and stormwater runoffs in streams, which eventually end up in the river. Domestic pollution contains nitrogen and phosphorus. These substances cause eutrophication and multiplication of algae. Algal blooms deplete the water's oxygen. We began our project with an educational visit to Alexandria Sanitation Authority where we learned how sewage is treated.

Research and experiments were conducted to determine the effect of water pollution on aquatic life. Apple Snails were used because of their sensitivity. For the control group, a 4oz. jar was filled with distilled water, a snail, and plant elodea. For the experimental group, two jars were used, and water was collected from a nearby-polluted stream that runs into the Potomac River. The first 4oz. jar was filled with polluted stream water, a snail, and plant elodea. The second 4oz. jar was filled with the polluted stream water that was mixed with nitrogen and phosphorus from fertilizer with a concentration of 5g/gallon. Observations were taken daily for one week. The experiment was replicated.

Comparing the experimental and the control group, the results supported the hypothesis. The snails in the polluted water had a shorter life span, less activity and less consumption of food than the snails in the clean water. The more pollution the water contained the shorter the life span was.

Acknowledgments

1. Dr. Safiya Samman from USDA forest services
2. Mr. Adeeb Saleh from ASA
3. Mr. George Floyd from ASA