The key takeaways from the 2018 monitoring season are:
• Nitrogen, phosphorus, and chlorophyll concentrations continued to decline from peaks in 2015. • Even with the recent declines, Echo Lake's nutrient concentrations and algal growth were still fairly high, and the water was less clear. • Echo Lake's high nutrient concentrations and nitrogen-to-phosphorus (NP) 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 late October. Toxin testing found microcystin present at 5.0 µg/L, below the Washington State Recreational Guideline of 6.0 µg/L.
Please see below for a link to the full 2018 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).
