Ken Lake Water StudyKen Lake Water Study

6/6/066/6/06

Conducted by Conducted by

Chris Sogn, Avanti High School Science TeacherChris Sogn, Avanti High School Science TeacherDavid H., Avanti High School Multi-Talented StudentDavid H., Avanti High School Multi-Talented Student

PurposePurpose

The purpose of our study is to:The purpose of our study is to: See how our lake has changed in the past 17 See how our lake has changed in the past 17

years. years. Measure the health of our lake to serve as a Measure the health of our lake to serve as a

baseline.baseline. Educate Ken Lake residents on ways to keep Educate Ken Lake residents on ways to keep

the lake healthy.the lake healthy.

ImplicationsImplications

The underlying reason we are so avidly The underlying reason we are so avidly testing and studying the lake is in testing and studying the lake is in response to proposed development of the response to proposed development of the watershed that drains into the lake.watershed that drains into the lake.

We don’t want to see our beautiful forests We don’t want to see our beautiful forests destroyed and we want to inform people destroyed and we want to inform people about how to preserve the quality of the about how to preserve the quality of the water. water.

Arial View of Ken LakeArial View of Ken Lake

Regional topographyRegional topography

Formation of Ken LakeFormation of Ken Lake

Ken Lake formed thousands of years ago. Ken Lake formed thousands of years ago. It is not man made.It is not man made.

It it is the product of a glacier which It it is the product of a glacier which retreated into the lake’s location during the retreated into the lake’s location during the Vashon Glacier recession.Vashon Glacier recession.

Geology of Ken LakeGeology of Ken Lake

Depth Map of Ken LakeDepth Map of Ken Lake

Factors That Influence Water Factors That Influence Water QualityQuality

The Lake’s pH (acidity).The Lake’s pH (acidity). Water TemperatureWater Temperature Amount of Dissolved OxygenAmount of Dissolved Oxygen BacteriaBacteria TurbidityTurbidity Amount of NutrientsAmount of Nutrients

Tests PerformedTests Performed Dissolved Oxygen- A test Dissolved Oxygen- A test

to see how much oxygen is to see how much oxygen is in the water.in the water.

Fecal Coliform- A test to Fecal Coliform- A test to measure the amount of measure the amount of bacteria in the water.bacteria in the water.

pH- A test to determine the pH- A test to determine the acidity of the water.acidity of the water.

Secchi Depth- Determines Secchi Depth- Determines turbidity (water clarity) and turbidity (water clarity) and depth of water.depth of water.

Nutrients- A test to find the Nutrients- A test to find the amount of phosphates and amount of phosphates and nitrates in the water.nitrates in the water.

Optimal Water Quality StandardsOptimal Water Quality Standards

Dissolved Oxygen- 9mg dissolved Oxygen Dissolved Oxygen- 9mg dissolved Oxygen per liter of water.per liter of water.

Fecal Coliform- Less than 50 fecal Fecal Coliform- Less than 50 fecal colonies per 100 ml of water.colonies per 100 ml of water.

pH- Between a rating of 7 and 8.pH- Between a rating of 7 and 8. Secchi Depth- The clearer the water the Secchi Depth- The clearer the water the

better.better.

Data tableData tableTest PerformedTest Performed Optimal ResultOptimal Result Test ResultTest Result

Dissolved Dissolved OxygenOxygen

9mg/l9mg/l 9.5mg/l9.5mg/l

Fecal ColiformFecal Coliform 50 colonies per 50 colonies per 100ml100ml

Results ranged from 10 to Results ranged from 10 to 29 colonies at the East 29 colonies at the East Beach and 0 to 59 at the Beach and 0 to 59 at the West Beach.West Beach.

pHpH Between 7 and 8Between 7 and 8 77

Secchi DepthSecchi Depth Clear to the bottom. Though Clear to the bottom. Though some variation should occur some variation should occur over the seasons.over the seasons.

At two locations (9.5 ft and At two locations (9.5 ft and 12ft) the water was clear all 12ft) the water was clear all the way to the lake bottom.the way to the lake bottom.

Water Test results, 2008Water Test results, 2008

Where to Go From Here?Where to Go From Here?

More Tests?More Tests?

Suggestions?Suggestions?

……??

ResourcesResourcesA 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.