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.

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 - 2020 SAMPLING RESULTS/LOCATIONS 

 

 UPDATE ON CLEAR LAKE CYANOTOXIN LEVELS:

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At our last sampling event on 11/23/20, we collected water samples from 21 sites on and in the lake.  Cyanobacteria blooms were in most locations, so we further reviewed those samples by microscopy.  Water samples were sent off for Microcystin cyanotoxin levels. 

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

CAUTION  / WARNING / DANGER   SIGNAGE

 11/23/20 RESULTS:

2 sites above the California DANGER Trigger Level:

AP01                    606.80 µg/L

RED01                       35.00

   

     sites above the California WARNING Trigger Level:

CL-4**                   15.20 µg/L

CL-3**                     7.35

SHADY01              7.36

CLOAKS01            7.13

KEYS03                  7.06       

14 sites above the California CAUTION Trigger Level:

JB                             4.93 µg/L

ELEM01                  4.67

SBMMEL01           4.55

LPTNT                   3.29 

GH                          3.05

LS2                          2.71

LC01                        1.83

CL-1**                     1.83

HB                           1.70

KP01                       0.94

BVCL6                   0.91

CLV7                      0.90

RODS                    0.86

CP                           0.81     

1 site below CA Caution Level:

LUC01                   0.74 µg/L

2 sites not sent off for analysis because no bloom:

BP

UBL

** samples collected 11/3/2020

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

Off season sampling of 1x month is being planned and should begin in December. 

EPA STAFF:

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

Alfred Balletto, Water Quality Program Coordinator

​Katherine Schrade, Environmental Specialist

Richard White, Solid Waste Technician