o Previously: Public health officials issued a warning Aug. 6 to stay out of Vancouver Lake because of toxic algae.
o What’s new: Clark County Public Health lifted the advisory after tests indicated algae no longer is a health threat.
o What’s next: The water at Vancouver Lake’s swim beach will be tested again Monday.
Clark County health officials have lifted a weeklong warning to stay out of Vancouver Lake, but people should still check water quality before they dive in this weekend.
o Previously: Public health officials issued a warning Aug. 6 to stay out of Vancouver Lake because of toxic algae.
o What's new: Clark County Public Health lifted the advisory after tests indicated algae no longer is a health threat.
o What's next: The water at Vancouver Lake's swim beach will be tested again Monday.
The advisory, which cautioned against direct water contact, had been in place since Aug. 5 because of high levels of cyanobacteria, a blue-green algae.
Results of the most recent test indicates that the algae is no longer a health threat.
However, people should exercise caution when they try to beat the weekend heat in the lake — just in case a sudden algae bloom materializes in the next couple of days.
“Although today’s levels are safe, we urge people to avoid water contact if a bloom develops this weekend,” Tom Gonzales, a public health program manager, said Thursday. “A bloom would give the water a scummy texture and a green color. The water may also appear bluish, brownish or reddish-green.”
Clark County Public Health tests water quality every two weeks at Vancouver Lake, from May through September.
“We will test the swim beach on Monday to determine if cyanobacteria levels remain below the threshold after the weekend,” Gonzales said.
This month’s warning marked the second time in three years health officials have issued an advisory at Vancouver Lake.
Samples taken on Aug. 3 showed 224,000 cyanobacteria cells per 100 milliliters (not quite a half-cup) of water.
The newest reading showed 90,000 cells per 100 milliliters, Gonzales said. That’s below the World Health Organization standard of 100,000 cells.
Cyanobacteria produce toxins that can cause respiratory illness, rashes and, in extreme cases, kidney and liver damage or death.
In addition to the satisfactory cell count, the recent water samples also offered encouraging findings on the toxins.
“Toxin levels were very low,” Gonzales said. “That’s why we made the call to lift the advisory — with the recommendation that people exercise caution when they get into the water.”
Blue-green algae blooms typically occur during warm weather when the water is stagnant.
Scientists at Washington State University Vancouver have been studying the lake for three years, while a watershed partnership of local agencies and community groups is looking at issues that influence water quality. The Vancouver Lake Watershed Partnership includes Vancouver-Clark Parks and Recreation, Clark County, Port of Vancouver, city of Vancouver and the Fruit Valley Neighborhood Association.
