Levels of Pollutants in Local Waters

1. Levels of Pollutants in Local Waters Emily Young Carr Grade 9 Academy of Notre Dame de Namur

2. Problem • Is there a direct correlation between the extent of pollution in local waters and the location of the body of water?

3. Research • Factors that cause water pollution include… • Industry- many companies dispose of waste in freshwater sources like rivers. • Sewage and Wastewater- increases with a high population density and the presence of industry. • Thermal pollution- when heated water is released into a body of water, often an industrial practice • Some common tests used to evaluate purity of water are pH balance, buffering capacity, and level of bacterial contamination. • pH balance measures how acidic or basic a substance is, 0-14, the higher the more basic. 7 is neutral. • A normal pH measurement for freshwater should be between 6.5 and 8. • Major or sudden changes in pH balance are stressful for the water’s ecosystem.

4. Research • Buffering Capacity is the amount of acid or base needed to change the pH balance of a solution. • A high buffering capacity indicates the water tested is hard water while a low buffering capacity indicates soft water. • Hard water is water with a high mineral content (common minerals are calcium and magnesium); soft water is the opposite. • Water pollution is not linked with only hard or soft water.

5. Hypothesis • If a body of water lies in close proximity to industry, and/or there is a high population density in the area, then higher levels of pollutants will found in the water.

6. Necessary Materials • 9 sterile 50mL conical tubes • 27 sterile 14mL round-bottom tubes • Pipettes of varying size • Pipette aid • 9 LB agar plates • Bacteria loops • 54 mL of LB broth • Diluted HCl at .02 N HCl • pH meter • Shaker incubator • Bunsen burner with fire source • Cold room • Water from 9 different local bodies of water

7. Procedure (Water Collection) • Eight local bodies of water were chosen from which to collect water samples. • The first five samples were collected from suburban bodies of water. The bodies of water from one to five are: Darby Creek, Harriton Plantation Pond, Rhoads Pond, Dove Lake, and Mill Creek. • The remaining three samples were collected from urban bodies of water. The bodies of water from six to eight are: the Delaware River, the Schuylkill at the Boathouses, and the Schuylkill at the Gladwyne Exit. • All samples were gathered in 50mL conical tubes.

8. Procedure (pH balance) • The pH meter was standardized to pH7. • The pH of the eight water samples and the control were tested. • Tests were done three times for each sample for statistical significance. • The probe was cleaned after each sample was tested.

9. Procedure (Buffering Capacity) • 14 mL tubes were filled with 2 mL of water sample per tube, 3 tubes for each water sample • The pH meter was standardized to pH7. • Acid (HCl) was added in μL increments to the water sample until it reached the neutral measurement of pH 7 • HCl Concentration: 0.02 N HCL • Tests were done three times for each sample for statistical significance. • The probe was cleaned between tests.

10. Procedure (Bacterial Growth) • 14mL tubes were labeled 1-9 with 3 tubes per water sample. • The tubes were filled with 2mL of LB broth and then 20μL of water sample was added using a pipette aid. • The 27 tubes were put into a shaker incubator at ideal bacterial growth conditions and left in overnight. • 37 degrees C • 9 LB agar plates were separated into thirds and the thirds were labeled A, B, and C. • Plates were streaked, each of the three bacterial cultures for a water sample were put into a different third. • Plates were stored in 37 degrees C oven and bacteria was allowed to grow overnight. • Plates were evaluated for bacterial colonies the next day.

11. Variables • Independent Variable- the water samples from varying bodies of water • Dependent variable- pH balance, buffering capacity, and bacterial growth • Control- tab water from laboratory facility • Constants- the materials used; the amount of water sample collected; the amount of LB broth used per sample; the temperature of the lab facility, cold room, shaker incubator, and water samples; the location of experimentation; and the amount of time allowed for bacterial growth and observation

12. Data and Results • Abbreviations: • Darby Creek: WS1 • Harriton Plantation Pond: WS2 • Rhoads Pond: WS3 • Dove Lake: WS4 • Mill Creek: WS5 • Delaware River: WS6 • Schuylkill at Boathouse: WS7 • Schuylkill at Gladwyne Exit: WS8 • Tap Water from a Lab Facility: Control

13. pH Measurements

14. Buffering Capacity

15. Bacterial Growth

16. Conclusion • Hypothesis- If a body of water lies in close proximity to industry, and/or there is a high population density in the area, then higher levels of pollutants will found in the water. • The hypothesis was neither supported nor unsupported • Results too vague to clearly support correlation • Higher percent of urban bodies of water had bacteria, but some suburban bodies of water had bacteria also • Did not consider extent of agricultural pollution • Possible Errors and Improvements • There should be a greater number of water samples from both groups • More tests could be preformed to test pollutants in water

17. Recognitions • Thank you to all sources used. • Pollution by Debra A. Miller • “EPA to Staunch Flood of Storm Water Runoff Polluting U.S. Waterways” Scientific American • “Water Pollution” http://en.wikipedia.org/wiki/Water_pollution • “Water Pollution and Society” http://www.umich.edu/~gs265/society/waterpollution.htm • “On Course for a Cleaner Hudson” The New York Times • “Optimum Freshwater pH” http://www.bestfish.com/tips/102998.html • “Hard vs. Soft Water Explained” http://www.freedrinkingwater.com/water-education • “The Causes of Water Pollution” http://www.water-pollution.org.uk/causes.html • Thank you to everyone in the audience for listening to my presentation. I would be happy to answer any questions you may have about my project.