CLEAR LAKE CYANOTOXIN ISSUES

EPA

The Environmental Protection Department (Big Valley EPA) researches, plans, funds, and implements projects that protect the Tribe’s environment.  Return to Big Valley EPA's page.

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The Big Valley Band of Pomo Indians began a cyanobacteria and cyanotoxin monitoring program on Clear Lake in 2014 with another shoreline Tribe, Elem Indian Colony. Together the two Tribes' Environmental Departments have collaborated with equipment, resources and time to test the water for toxins produced by cyanobacteria (AKA “Blue Green Algae”). These toxins are called cyanotoxins and can be neurotoxins, liver toxins and skin toxins. The Tribes began this program because despite the fact that Clear Lake had thick, noxious blooms covering its surface every summer since 2009, there was no regular and active monitoring of these blooms for the cyanotoxins that the California Office of Environmental Health Hazard Assessment (OEHHA) had reviewed and suggested Action Levels for in 2012, and for which the World Health Organization provided guidance regarding exposure in the 1990’s.  OEHHA's Report  

CURRENT RESULTS - 2022 SAMPLING RESULTS/LOCATIONS 

Results 7-26-22 map final.jpg

 UPDATE ON CLEAR LAKE CYANOTOXIN LEVELS:

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SUMMER MONITORING OCCURRING, NEXT SAMPLING EVENT AUGUST 9, 2022

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On July 26th, Big Valley EPA staff sampled at 19 locations on the Clear Lake shoreline. Visible blooms were noted at 14 sites. 

 

We conducted microscopy on all samples and noted the following:

  • DOMINANT GENUS:  

 Lyngbya sp.

  • SECONDARY GENUS:

Gloeotrichia sp.

  • ADDITIONAL GENERA NOTED:

 Microcystis sp.

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For more information on which cyanobacteria can produce which toxins: https://bit.ly/CyanobacteriaToxinsChart
 

We submitted 16 samples for Microcystin toxin and qPCR analysis, and analysis.   Results are below.  

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Identified map signage recommending restricted activity is based on CalOEHHA toxin trigger levels. 

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CAUTION  / WARNING / DANGER   SIGNAGE

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 7/26/22 RESULTS are for Microcystin unless otherwise noted:

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DANGER (Anything above 20):

ELEM01                      636 µg/L

CLOAKS01                  242.4

AP01                             176

SBMMEL01                 118

BP                                   45.53

 

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WARNING (Anything above 6):

SHADY01                13.39 µg/L

RED01                      11.79

CLV7                          8.13

LC01                          6.30

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CAUTION (Anything above 0.8):

JB                                3.88 µg/L

KP01                          2.35

CP                              1.22 

LPTNT                      0.83 

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BELOW CAUTION:

BVCL6                      0.66 µg/L

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NO DETECT/NOT LIKELY:

KEYS03

RODS

LUC

HB

GH

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SITES NOT SAMPLED DURING THIS SAMPLING EVENT ARE NOT SHOWN ON THE MAP.

SITE ID NAME SPREADSHEET.JPG

EPA STAFF:

Sarah Ryan, Environmental Director (707)263-3924 x132 and (707)349-4040 cell

Alix Tyler, Water Quality Program Manager

​Katherine Schrade, Environmental Data Coordinator

Richard White, Pollution Prevention Coordinator

Alicia Castellanos, Environmental Assistant

Nijoel McCloud, Environmental Technician

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