Combating toxic algae on Green Lake with vacuum, sponges
Oct 9, 2012, 12:11 PM | Updated: 1:57 pm
You can look at Green Lake - just don't get in. Toxic levels of photosynthetic cyanobacteria, or "blue-green algae," have led to the closure of Green Lake for all wading and swimming activities. It has also left an ugly, green scum on the water. (MyNorthwest.com Photo/File)
(MyNorthwest.com Photo/File)
Workers hope vacuums can help solve the problem on Green Lake. They’re attempting to get rid of the blue-green algae that has closed the water to swimmers.
“We’re trying a couple of different approaches, very low-cost approaches – kind of quick and easy ways of greatly reducing the toxicity of this naturally occurring bacteria that’s in the water right now,” says Doug Williams with the King County Department of Natural Resources.
Workers are targeting coves where the algae has accumulated into a layer of scum on top of the water. They have also put out some big, absorbent sponges to see if they can soak up the tainted water.
What workers are able to retain will be taken back to the lab to compare the toxicity in the different water samples. Williams says they want to know if the scum has a higher level of toxicity than the rest of the water. They will also consider whether the vacuum or the sponges might be a reasonable option to combat the algae growth.
Alum treatments have previously been used to reduce the level of photosynthetic cyanobacteria in Green Lake, but it is very expensive. The last treatment in 2004 cost over $1 million.
The lake closed last week to wading, swimming and “wet-water boating” activities and remains off limits. The county is also warning pet owners to keep their dogs away from Green Lake; the bacteria can also be harmful to animals.
