Of the thousands of species of fresh water algae only a relative handful produce toxins harmful to human health.
The toxin-producing “Cyanobacteria,” or blue-green algae, has been identified in 23 Oregon lakes, reservoirs and rivers over the last ten years.
This year the Department of Health and Human Services issued warnings for twelve different bodies of water, the most it's issued in any one year. Becca Bartleson reports.
Toxins produced by these neon colored blooms can have harmful, even deadly, side effects.
They can cause tingling, numbness and damage to the central nervous system. And these toxins can not be destroyed by filtration or boiling.
Oregon health advisories recommend people avoid contact with any water containing blooms.
The pond in Portland’s Laurelhurst Park has had an annual bloom for the past three years. Signs were posted and a fence installed to keep dogs from drinking and swimming in it.
John Reed: "I like to liken it to an anti-freeze green color, it's very striking, it's not such that murky green, it's real bright green so it's very evident."
John Reed is with Portland Parks and Recreation.
He says algae does not always produce toxins. And testing for toxins is expensive. Also, it can take weeks to get the results back. Reed says he likes to err on the side of caution.
John Reed: "We have relied mostly on just the identification and density testing since it's much faster, it's much less expensive so we're just assuming that there's always a level that's a problem here."
Oregon's health department is required to release a public health advisory after a bloom is identified. But the state is not required to pay for the identification, or for monitoring toxin levels after the advisory is issued.
Deanna Conners specializes in toxicology for the Oregon Department of Health and Human Services.
Deanna Conners: "The state does not monitor these blooms, the state encourages local watershed groups to get together, track these hazards, be aware of these hazards, and act to protect themselves and prevent these blooms."
But some communities are too small to afford the tests.
Siltcoos Lake is one of the four Oregon sites where health advisories are still in effect.
Tiny Dunes City is located nearby and most local residents get their drinking water from the lake. But most have not gotten any official warning that the water could contain toxins.
Richard Koehler is on the city council and a member of the city's water quality committee. He says Oregon should be monitoring its lakes.
Richard Koehler: "There's a loose string here between the local testers and the state being able to afford the test, or being able to be willing to do the test."
Koehler says that last year Dunes City spent more than $13,000 testing for toxins. This year the bloom was smaller and the city was unwilling to foot the bill.
Richard Koehler: "We take the samples, we send them in, but there's always going to be a missing link until the state takes on the responsibility for the cost of the tests. We're all for testing and putting in as many hours as we can for this, but we have a very small budget."
The Oregon Department of Health and Human Services says it encourages smaller communities to come together to share resources and let people know about the risks.
That's what Dunes City says it intends to do. City counselor Richard Koehler says the city hopes to join forces with Lane and Douglas Counties to notify people by phone and email in the event of future blooms.