Seattle City Council to speed Green Lake toxic algae cleanup, prevent closures

In the wake of toxic algae blooms that have closed Green Lake over the past several summers, the Seattle City Council is stepping up efforts to speed cleanup and prevent closures for years to come.

Councilmembers Jean Godden and Mike O’Brien announced Thursday the Council’s Budget Committee unanimously approved accelerated funding for aggressive new steps to treat the water in time for summer of 2016, a full year sooner than anticipated.

“It’s an amazing place. It’s the most used park in the city system, one of the most used parks in the state,” O’Brien says. “For me it just puts a smile on my face to see so many people loving this park. But a big component of it is to be able to get in the water.”

Speeding up the funding will allow the Department of Parks and Recreation to begin necessary water quality testing and permitting from the Department of Ecology over 2015, which is required before treatment can begin, O’Brien says.

The treatment, which uses a chemical called alum, can only be done in warmer weather to be effective, so it wouldn’t be conducted until April 2016.

“It’s not as simple as us just getting a shaker and shaking it around the lake. You have to do a fair amount of research and sampling to understand the different conditions at different parts of the lake,” O’Brien says.

So what causes the problem in the first place? O’Brien says ever-present blue-green algae in Green Lake becomes toxic when warm weather and more activity in the lake stir up phosphorus sediments from the bottom and other nutrients that the algae feed on. The algae blooms then grow and become toxic to people and pets.

Storm water runoff and fertilizer runoff from neighboring lawns are significant contributors to the algae problem as well, O’Brien says.

“We continue doing things in the Green Lake basin that are adding to the runoff in the lake. I think it’s important to take a hard look at things we could do to prevent aggravating the problem in the future. The treatment isn’t cheap.”

O’Brien says the city has set aside $1.5 million for the treatment, based on past experience. Once the treatment is conducted, it should last six or seven years.

But O’Brien says unfortunately, since the treatment can’t be done until 2016, the lake could face another algae-fueled closure next summer.

“We’re looking to see if there’s anything the Parks Department can do to speed things up, but it doesn’t look like there are a lot of options,” O’Brien says.

The full Council is scheduled to vote on the Budget Committee’s recommendation on Monday, November 24.