Ty Swenson
One of two floating islands seen at Hicklin Lake in Lakewood Park of White Center. The islands were installed by King County to experiment with their effectiveness in naturally leaching pollutants from the lake, which has been heavily polluted for decades.

Cleanup hopes rest on two floating islands installed at Hicklin Lake

Hicklin Lake in Lakewood Park of White Center is two steps closer to cleaning up its act.

During the week of July 15 – 19 King County’s Water and Land Resources Division installed two of four floating islands that are designed to grow vegetation that will naturally extract pollutants from the lake through their roots.

The floating island idea was hatched, investigated and presented to King County by Friends of Hicklin Lake, a community group focused on cleaning up Hicklin, headed up by the lake’s biggest champion in Dick Thurnau.

A breakthrough occurred earlier this year when King County Senior Limnologist Sally Bartley Abella obtained a $50,000 grant from the Washington Department of Ecology to pilot the islands.

The islands have been planted with a variety of plants from native roses to dogwood bushes to cattails, and a thin wire mesh surrounds them to keep waterfowl from climbing onto the islands where they could disturb the plants and dropping excrement that could add to the pollution they are trying to clean up. Earlier this year Abella said waterfowl are unlikely to fly in and land on the islands due to their small size.

King County scientists said the islands will start pulling nutrients almost immediately, but they won’t be operating at full capacity until two years from now. In the meantime, they will be measuring pollution levels (including fecal coliform – from human waste) at the onset and periodically throughout the pilot program’s life to determine effectiveness.

Abella said if the program is successful at Hicklin, floating islands could be used in other polluted lakes throughout King County as they require minimal maintenance and a relatively low initial cost.

Originally, King County hoped to install four islands but as bids came in they were only able to afford two at 600 square feet each, according to Thurnau. “It’s a start in the right direction,” he said.

While the floating islands do their job, King County is working with the Southwest Suburban Sewer District to reduce the level of pollutants making their way into Hicklin Lake in the first place. Abella said a significant source of pollutants is illicit connections of sewer lines to the stormwater drainage system that funnels into Hicklin. Those connections, which were likely made back in the 1950s, result in sewage making its way into the lake, raising fecal coliform levels. She said two illegal connections have been discovered and corrected so far, and they will be investigating to find more.

This post includes information from a prior Herald story, found here.

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