science environment

Public should avoid Vancouver Lake’s blue-green algae blooms, officials warn

By Monica Samayoa (OPB)
July 28, 2020 12:25 a.m.

Clark County health officials issued a cautionary advisory for people to avoid a popular Southwest Washington lake because a toxic algae may be present in the water.

A blue-green algae has bloomed in Vancouver Lake on Jul 27.

A blue-green algae has bloomed in Vancouver Lake on Jul 27.

Clark County Public Health


A blue-green algae or cyanobacteria has bloomed at Vancouver Lake. Clark County Public Health is awaiting toxicity level results from samples taken from the lake on Monday. For now, the agency is asking the public to avoid activities like swimming or boating that can lead to direct contact with the blue-green algae or scum, which can be unsafe for people and pets.

Vancouver Lake has periodically been closed because of blue-green algae blooms which typically need nutrients, warm conditions, and sunlight.


Clark County Public Health Program Manager Brian Schlottmann said the heat from the last couple of days has contributed to the large amounts of algae found in the lake. He said staff members came out to the lake two different times throughout the day on Monday. The first staff member went out for routine testing for e-coli in the lake and saw large amounts of blue-green algae. By the second visit, the amount of blue-green algae in the lake was extensive.

“It actually looked like somebody had dumped buckets of paint in the water, which is what we say to look for,” Schlottmann said. “I personally haven’t seen one this bad on Vancouver Lake before.”

Schlottmann said the bloom was first reported last week in some spots near the shoreline of the lake. The agency drew samples then and results came back with low toxicity and below the threshold. But now the agency has submitted new samples for testing and advised the public to avoid areas with scum.

He said the bloom is so extensive that if results come back above the toxicity threshold, the county will close the lake.

If above toxicity levels, blue-green algae produces toxins that can be harmful to people and deadly for small pets that drink the water. If in contact with skin, it can cause skin irritation and cause stomach irritation like vomiting if ingested.

The agency expects to have results later this week.