How to resolve AdBlock issue? LAKE COUNTY, Calif. – With lab results this week confirming low toxin levels in several samples taken late in June from Clear Lake and Blue Lakes, local health and tribal environmental officials are urging community members to both be aware and to use caution when recreating.
Local tribes including Big Valley Rancheria and Elem Colony run tests at about 17 sites on the water every two weeks from June through October, according to Big Valley Environmental Director Sarah Ryan.
Ryan said the sites tested are a good representation of public and private areas, beaches and parks. They look for everything from water chemistry to forms of pollution that affect fish or influence cyanobacteria, a naturally occurring bacteria.
Cyanobacteria also is called blue-green algae because it conducts photosynthesis. But Ryan said it’s not a true algae – it’s not a plant – and calling it such can be confusing.
“It can produce toxins,” she said.
Up until this week, this year’s lake testing, which was being done with in-house testing kits, had not detected any toxins, Ryan said.
But samples taken on June 19 and June 21 were submitted to a lab for further analysis, she said.
Those lab results, which came back this week, showed low toxin levels in several samples taken from Clear Lake near Clearlake and Lakeport and from Blue Lakes.
The detections included low levels of microcystin, a toxin that affects the liver and intestinal tract, as well as nodularin, another toxin from which it’s difficult to differentiate microcystin; and anatoxin-a, a neurotoxin, according to Lake County Public Health Officer Dr. Karen Tait.
The testing is showing some fairly low toxin levels. “It’s not at alarming levels,” Tait said.
Tait said that samples taken on June 19 on the lakeshore in Clearlake and Lakeport came back confirming the presence of microcystin.
The samples revealed 0.14 microgram per liter in Lakeport near the old TNT restaurant site and 0.13 microgram per liter at a site near Austin Park in Clearlake, Tait said.
“I have notified both city managers as of yesterday and provided them with links to the guidance documents and sample signage,” she said on Friday.
Tait emphasized that those levels are well below even the trigger for "caution."
She said the microcystin result is still within acceptable standards for recreational water use.
Based on voluntary state guidelines, the trigger level for increased monitoring and placement of a caution sign stating that people should stay away from scum and pets and livestock should be kept away from the water and scum is 0.8 micrograms per liter for microcystin, Tait said.
Tait said the tier one level of 6 micrograms per liters of microcystin in recreational waters would prompt the placement of a warning sign stating that swimming is not recommended and that pets and livestock should be kept away from the water. The “danger” tier is at 20 micrograms per liter.
“There’s no laws that apply to this at this point,” said Tait. “Everything is voluntary guidelines.”
Lab tests of samples taken on June 21 from Upper Blue Lake and Lower Blue Lake came back with findings of 0.15 microgram per liter for microcystin/nodularin for Upper Blue Lake, and for Lower Blue Lake 0.17 microgram per liter for anatoxin-a and 0.17 microgram per liter for microcystin/nodularin, Tait said.
Tait said any anatoxin detection should prompt a "caution" level of warning, while the "warning" level is 20 micrograms per liter and the danger level is 90 micrograms per liter.
Anatoxin-a was the toxin responsible for the death of a dog that had been swimming in the Russian River in Sonoma County in 2015, she said.
As for the response to the Blue Lakes detections, Tait explained, “Since these are voluntary guidelines and we are dealing with private property, we do not go in and post. However, I have provided this information to the resort owners so that they can consider posting on their own. There also needs to be some ongoing monitoring to determine the status of current conditions there, since considerable time has elapsed.”
Tait said she finds any toxin production to be of some concern, since it can go up or down easily.
At the same time, she noted that on Friday the results were nine days old. “The conditions could have changed” – for the better or the worse, she added.
Ryan said there are plans to conduct followup tests on those sites on July 5.
Tait said she feels strongly that the testing results need to be released so the public can be informed.
The county’s health department offers a general advisory in these cases: If you see something, like a mat of cyanobacteria, exercise caution and “stay out of it,” Tait said. That especially applies to dogs and children, which are much more susceptible.
“People can still go and have fun,” they just need to avoid areas with mat and not drink untreated water, Tait said.
She said that cyanobacteria is much like other things that have to be contended with when recreating in Lake County – from mosquitoes to rattlesnakes.
Big Valley has taken a different approach in light of the cyanobacteria blooms.
On Friday, the environmental department handed out an advisory to every household on the rancheria explaining that the presence of cyanobacteria had been confirmed along the rancheria’s shoreline, Ryan said. In-house testing had found no detect of two types of toxin and possible low detect of a third.
Tribal members are urged to use caution with the lake, and to prevent children and pets from swallowing any water, based on the advisory notice.
“Unless you can keep yourself and children from swallowing water while playing, it is best to stay out of the lake at this time,” the notice said.
The notice also stated that the advisory is in effect until further notice, with the tribe to notify members of the results of the followup testing planned for next week.
Concerns about cyanobacteria aren’t restricted to Lake County’s lakes.
A map of California featured at the state’s My Water Quality Web site showed close to 30 harmful algal blooms across the state since the start of May. Four of those blooms are located in Lake County, in Clear Lake and Blue Lakes.
And on Friday, the California Department of Water Resources and the county of Napa issued separate notices about cyanobacteria’s impacts on water bodies.
The state said people should stay out of the water at San Luis Reservoir in Merced County until further notice and avoid eating fish from the reservoir due to the presence of cyanobacteria, where on Friday the advisory level was increased from “warning” to “danger.” The advisory does not apply to O’Neill Forebay.
In the case of the San Luis Reservoir, a June 26 sample from the Basalt Boat Launch site contained 25.8 micrograms per liter of microcystins, a level that prompts danger signs to be posted at the reservoir.
In Napa County, the health department urged recreational water users to avoid close contact with bodies of water containing cyanobacteria. The agency reported that a pond in the Huichica Creek Unit, located at the end of Milton Road in Napa, was linked to the death of two dogs that swam in the water within the last week. Warning signs have been posted in the area.
The Statewide Guidance on Cyanobacteria and Harmful Algal Blooms recommends the following for waters impacted by cyanobacteria or blue-green algae:
· Take care that pets and livestock do not drink the water, swim through algae, scums or mats or lick their fur after going in the water. Rinse pets in clean water to remove algae from fur.
· Avoid wading, swimming or jet or water skiing in water containing algae blooms or scums or mats.
· Do not drink, cook or wash dishes with untreated surface water from these areas under any circumstances; common water purification techniques such as camping filters, tablets and boiling do not remove toxins.
· People should not eat mussels or other bivalves collected from these areas. Limit or avoid eating fish from these areas; if fish are consumed, remove the guts and liver, and rinse filets in clean drinking water.
· Get medical treatment immediately if you think that you, your pet or livestock might have been poisoned by blue-green algae toxins. Be sure to alert the medical professional to the possible contact with blue-green algae. Also, make sure to contact the local county public health department.
For more information, visit the sites listed below.
California Department of Public Health
http://www.cdph.ca.gov/healthinfo/environhealth/water/Pages/Bluegreenalgae.aspx
State Water Resources Control Board - California CyanoHAB Network:
http://www.mywaterquality.ca.gov/monitoring_council/cyanohab_network/index.html
CA Office of Environmental Health Hazard Assessment: Information on Microcystin
http://oehha.ca.gov/ecotoxicology/general-info/information-microcystins
US Environmental Protection Agency: CyanoHAB Web site
https://www.epa.gov/nutrient-policy-data/cyanohabs
US Environmental Protection Agency: Anatoxin-a report
https://www.epa.gov/sites/production/files/2015-06/documents/anatoxin-a-report-2015.pdf
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Officials urge caution due to low toxin levels found in some lake water samples
- Elizabeth Larson
