CAMANO ISLAND, Wash. (AP) — The Department of Natural Resources has returned to Camano Island again to remove creosote-coated pilings carried by the tide into Elger Bay.

In 2009, the DNR pulled 100 tons of creosote-coated pilings from the area, KING-TV reported.

Creosote was used for over a century to protect wood pilings in the salt water of Puget Sound. Creosote contains hundreds of chemicals, including known carcinogens.

Chris Robertson, Aquatic Restoration manager for DNR’s Aquatics Division, said last week that infrastructure has broken down over time and the pilings enter the aquatic system and end up along Washington shorelines.

Crews work year-round to remove pilings by hand, but in fragile areas where machinery would damage the landscape as on the Camano Island site, a helicopter is necessary.

“It’ll get dropped up in the cow pasture up there, and then trucked off to the landfill for disposal,” Robertson said.

Since 2003, the DNR has removed more than 54 million pounds of creosote pilings from Puget Sound. That work continues in an effort to protect the environment.

“They end up in a lot of our forage fish. Juvenile salmon use utilize places like this for rearing. And that chemical gets into the food chain and through the effects of bio-accumulation makes its way all the way up into into our whales,” Robertson said.