A sign posted in 2022 at Indian Creek Reservoir warns visitors of toxins produced by blue-green algae.
Photo by Kurt Hildebrand.
Test results for both El Dorado and Nevada beaches were negative for harmful algal blooms, though a shallow pond at Nevada Beach tested positive for a very low level of a cyanotoxin called saxitoxin.
The testing was conducted on July 8 and 10 after a person reported her dog died from drinking water at Lake Tahoe.
The Lahontan Regional Water Quality Control Board and the Nevada Division of Environmental Protection collected water samples as part of an ongoing investigation of a report that went viral on social media.
On Tuesday, lab results from lake water at both El Dorado Beach and Nevada Beach were announced to be nondetect for toxins associated with algal blooms.
“At Nevada Beach, results for a sample taken from a shallow pond not connected to the lake contained a very low level of a cyanotoxin called saxitoxin,” according to a joint statement from the two agencies. “The pond is partially fenced off and the Lahontan Water Board and NDEP are recommending further fencing to prevent dogs and their owners from accessing the area.”
The agencies determined the sampling based on an interview with the reporting party by the workgroup. Nevada Department of Environmental Protection issued an algae watch for the backwater pond at Nevada Beach.
Summer temperatures and shallow water are ideal for the growth of algal blooms. A warning for a bloom is in effect at Little Washoe Lake in Washoe Valley. There is also a caution for the south end of Indian Creek Reservoir in Alpine County.
The advisory at El Dorado Beach has been lifted and the water is designated safe for recreational activities, however the public is urged to always remain vigilant when visiting any waterbodies, practice healthy water habits, and to be aware of how to identify and report suspected harmful algal blooms.
“Doing so can keep loved ones, including dogs, along with other members of the public, safe from possible health impacts.
To stay updated on harmful algal blooms in California, visit the HABs portal.
To stay updated on harmful algal blooms in Nevada, visit the HAB Dashboard and the Weekly HAB Update. To learn how to identify HABs and what to do if you see a HAB, visit NDEP’s HAB Resource Page. For more information about the health effects of HABs, visit the Office of State Epidemiology Harmful Algal Bloom page.
Ongoing investigation
The agencies involved in water-sample testing cannot draw conclusions about the cause of death for the dog from these results; they can only speak to evaluating water quality and the presence of HABs. The California Interagency Harmful Algal Bloom-related Illness Workgroup (Illness Workgroup), which includes staff from the Office of Environmental Health Hazard Assessment (OEHHA), the State Water Resources Control Board (SWRCB), the California Department of Public Health (CDPH), and the California Department of Fish and Wildlife (CDFW), continues to investigate. All HAB-related illness reports submitted to the workgroup are evaluated based on available environmental data, interviews, health-related information and other pertinent data. Cases that have sufficient information to support determinations of HAB-related illnesses are reported to the Centers for Disease Control and Prevention’s One Heath Harmful Algal Bloom System.
