Girl Scouts compare water samples

Group 938 visited Big Rock Park recently and compared the creek water to water from Sunken Gardens, Knoxville drinking water, and Pella drinking water.




Both Sunken Gardens and the Big Rock entrance water contained sulfate, probably from lawn chemicals. Sulfates are found in consumer products such as shampoos, are released by decomposition, and are prevalent in lawn treatment chemicals. They are not horribly toxic but they can cause skin irritation and intestinal discomfort. The entrance and Sunken Gardens traces of bacteria. Big Rock and Knoxville water were fairly hard with a higher alkalinity than the other waters. This isn't harmful to health but can leave a white residue in pipes and on items washed in the water!



After testing the water, the troop headed for the rock for imaginative play and time in nature.




Did you know that Lake Red Rock is one of the most polluted bodies of water in the United States? Urban streams such as at our creek can reduce pollution and prevent flash flooding. They are also vulnerable to human activity. It was wonderful to have citizen scientists visit our park and take an interest in water quality. Just remember, anything you put on your yard can end up in our urban stream! The scouts found traces of lawn chemicals even though we haven't had much rain. If you can cut back on those frequent applications, please consider doing so.


In follow up tests, our creek oxygen concentrations are back up to healthy levels following the September rain. In fact, one spot had the same level of dissolved oxygen as Sunken Garden, which is aerated with a fountain.



Sunken Gardens and Big Rock Creek show similar levels of oxygen, bacteria, and lawn chemicals.


Many thanks to the Pella Community Foundation for funding the water quality study !(https://www.pellacommunityfoundation.org/non-profits)