1. Ken Lake Water Study 6/6/06 Conducted by Chris Sogn, Avanti High School Science Teacher David H., Avanti High School Multi-Talented Student

2. Purpose  The purpose of our study is to: See how our lake has changed in the past 17 years. See how our lake has changed in the past 17 years. Measure the health of our lake to serve as a baseline. Measure the health of our lake to serve as a baseline. Educate Ken Lake residents on ways to keep the lake healthy. Educate Ken Lake residents on ways to keep the lake healthy.

3. Implications The underlying reason we are so avidly testing and studying the lake is in response to proposed development of the watershed that drains into the lake. We don’t want to see our beautiful forests destroyed and we want to inform people about how to preserve the quality of the water. We don’t want to see our beautiful forests destroyed and we want to inform people about how to preserve the quality of the water.

4. Arial View of Ken Lake

5. Regional topography

6. Formation of Ken Lake  Ken Lake formed thousands of years ago. It is not man made.  It it is the product of a glacier which retreated into the lake’s location during the Vashon Glacier recession.

7. Geology of Ken Lake

8. Depth Map of Ken Lake

9. Factors That Influence Water Quality  The Lake’s pH (acidity).  Water Temperature  Amount of Dissolved Oxygen  Bacteria  Turbidity  Amount of Nutrients

10. Tests Performed  Dissolved Oxygen- A test to see how much oxygen is in the water.  Fecal Coliform- A test to measure the amount of bacteria in the water.  pH- A test to determine the acidity of the water.  Secchi Depth- Determines turbidity (water clarity) and depth of water.  Nutrients- A test to find the amount of phosphates and nitrates in the water.

11. Optimal Water Quality Standards  Dissolved Oxygen- 9mg dissolved Oxygen per liter of water.  Fecal Coliform- Less than 50 fecal colonies per 100 ml of water.  pH- Between a rating of 7 and 8.  Secchi Depth- The clearer the water the better.

12. Data table Test Performed Optimal Result Test Result Dissolved Oxygen 9mg/l9.5mg/l Fecal Coliform 50 colonies per 100ml Results ranged from 10 to 29 colonies at the East Beach and 0 to 59 at the West Beach. pH Between 7 and 8 7 Secchi Depth Clear to the bottom. Though some variation should occur over the seasons. At two locations (9.5 ft and 12ft) the water was clear all the way to the lake bottom.

13. Water Test results, 2008

14. Where to Go From Here? More Tests? Suggestions?…?

15. Resources A special thanks to Anne Mills and South Sound Green for providing materials and resources with such expediency! Thank you to the Washington State Department of Ecology for guidance and resources in conducting this study.