The key takeaways from the 2021 monitoring season are:
• Echo Lake continues to have high nutrient concentrations and algal growth, and less clear water. • Echo Lake’s high nutrient concentrations and nitrogen-to-phosphorus (N:P) ratios below 25 both indicate that Echo Lake is likely to have algal blooms dominated by cyanobacteria (which have the ability to produce toxins). • An algal bloom was sampled for toxin testing in April, May, October and November. Toxin testing found elevated anatoxin concentrations: 114 µg/L, above the Washington State Recreational Guideline of 1 µg/L. In 2021, Echo Lake was closed due to high anatoxin concentrations from April - May. Echo Lake beach was also closed due to bacteria concentrations for 15 days in August.
Please see below for a link to the full 2021 Echo Lake Monitoring Report.
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The average of these three TSI indicators during the growing season can be used to place lakes in one of three broad categories: <40 = oligotrophic (low productivity), 40 to 50 = mesotrophic (moderate productivity) >50 = eutrophic (highly productive).