$name - King County

Green Lake Duck Island Launch A734_GM21 only cyanotoxins

For algal toxin data please visit the State Toxic Algae web page and follow the “Find Lake” menu.

Please select a site and a year

Sample Date	Temperature (°C)	Temperature (°F)	Included in Bacteria Geomean Calculation?	Daily Average Bacteria
09/23/2019	18.0	64.4	No	not sampled
09/16/2019	19.0	66.2	No	not sampled
09/09/2019	21.0	69.8	No	not sampled
09/03/2019	21.0	69.8	No	not sampled
08/26/2019	23.0	73.4	No	not sampled
08/19/2019	23.0	73.4	No	not sampled
08/12/2019	22.0	71.6	No	not sampled
08/05/2019	25.0	77.0	No	not sampled
07/29/2019	24.0	75.2	No	not sampled
07/22/2019	24.0	75.2	No	not sampled
07/15/2019	23.0	73.4	No	not sampled
07/08/2019	21.0	69.8	No	not sampled
07/01/2019	22.0	71.6	No	not sampled
06/24/2019	20.0	68.0	No	not sampled
06/17/2019	23.0	73.4	No	not sampled
06/10/2019	21.0	69.8	No	not sampled
06/03/2019	20.0	68.0	No	not sampled
05/28/2019	19.0	66.2	No	not sampled
05/20/2019	18.0	64.4	No	not sampled
05/13/2019	19.0	66.2	No	not sampled

Table Legend

Cell Color	Bacteria Value	Concern Level
	Individual day <= 200 CFU/100 ml	Low Concern - safe for swimming
	Individual day > 200 & <= 1000 CFU/100 ml	Moderate Concern – still safe for swimming
	Individual day > 1000 CFU/100 ml or geometric mean > 200 CFU/100 ml	High Concern – probable closure. For more information see Beach Closure Protocol

NOTE: Beach closure and reopening decisions are made by Public Health – Seattle & King County. Decisions are based on these results plus additional information about beach conditions, and may not always match the concern levels shown here.

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NOTE: Duck Island Launch is only monitored for algal toxins, not fecal coliform bacteria.