National Park Service
U.S. Department of the Interior
LAKE MEAD NATIONAL RECREATION AREA News Release
June 12, 2013
Release No.: 2013-43
Contacts:
Christie Vanover, National Park Service, 702-283-2344
Bronson Mack, Southern Nevada Water Authority, 702-249-5518
Edwin Lyngar, Nevada Department of Wildlife, 775-741-1004
SWIMMING ADVISORY LIFTED AT LAKE MEAD, NO TOXINS FOUND
BOULDER CITY, Nev. - Swimmers are welcome back in the water at the Overton Arm of Lake Mead. The National Park Service lifted the no-swim advisory after lab results showed no toxin producers were found in the water.
Park officials issued the precautionary advisory June 8 after a foamy substance and around 25 dead carp were observed across an 8-mile stretch of the northern part of the lake.
“While we haven't received anything definitive as to the cause, we have reasonably evaluated the situation," said Christie Vanover, park spokesperson. “Through all the scientific investigation, nothing dangerous to humans has been found."
The National Park Service worked with the Southern Nevada Water Authority, Nevada Department of Wildlife and the Nevada Division of Environmental Protection to test the water and conduct field observations.
Along with issuing a swimming advisory, the National Park Service and SNWA increased monitoring at water intake and treatment facilities. There were no noted concerns with incoming water quality. Water temperature, specific conductance, pH and dissolved oxygen values were all within the usual values for this region of the lake. Water samples were free of microcystis algae and no toxins were found. Foam samples contained non-toxic, common freshwater algae, especially diatoms. Most of the diatoms were dead, and the foam appeared to be made up of proteins released from the dead algae.
“It is unclear if the fish die-off was related to the foam," said Vanover. “The foam does seem to be dissipating and no recently dead fish have been found. We will continue to observe the area with routine patrols."
If people see obvious patches of foam that haven't yet dissipated, it is best to avoid them.
“We apologize for any inconvenience this may have caused our visitors. Our first priority is always visitor safety," Vanover added.
-NPS-
Source: U.S. Department of the Interior, National Park Service
