The Lahontan Regional Water Quality Control Board (Lahontan Water Board) and the Nevada Division of Environmental Protection (NDEP) collected water samples on July 8 and July 10 at two Lake Tahoe beaches, El Dorado Beach in California and Nevada Beach in Nevada. The samples are part of the California Interagency Harmful Algal Bloom (HAB)-related Illness Workgroup’s (Workgroup) ongoing investigation into a dog’s death in the area.
Lab results from lake water at both El Dorado Beach and Nevada Beach were non-detect for toxins associated with HABs. At Nevada Beach, a sample taken from a shallow pond not connected to the lake contained a very low level of a cyanotoxin called saxitoxin. The pond is partially fenced off, and the Lahontan Water Board and NDEP recommend further fencing to prevent dogs and their owners from accessing the area. The locations for water sampling were determined based on an interview with the reporting party by the Workgroup.
The Lahontan Water Board recommends no advisory at El Dorado Beach for HABs, while NDEP recommends no advisory at Nevada Beach for the lake itself. However, NDEP has issued a “HAB Watch” advisory specific to the backwater pond at Nevada Beach.
The advisory at El Dorado Beach has been lifted, designating the water as safe for recreational activities. However, the public is urged to remain vigilant when visiting any waterbodies, practice healthy water habits, and be aware of how to identify and report suspected harmful algal blooms. This vigilance can help keep loved ones, including dogs, safe from potential health impacts from HABs.
To stay updated on harmful algal blooms in California, visit the HABs portal. For updates in Nevada, visit the HAB Dashboard and Weekly HAB Update. For information on identifying HABs and actions to take if you see one, visit NDEP’s HAB Resource Page. For more details about health effects of HABs, visit the Office of State Epidemiology Harmful Algal Bloom page.
The agencies involved in water-sample testing cannot draw conclusions about the cause of death for the dog from these results; they can only evaluate water quality and presence of HABs. The California Interagency Harmful Algal Bloom-related Illness Workgroup (Illness Workgroup), which includes staff from multiple state departments such as OEHHA, SWRCB, CDPH, and CDFW, continues its investigation. 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 with sufficient information supporting determinations of HAB-related illnesses are reported to the Centers for Disease Control and Prevention’s One Health Harmful Algal Bloom System.