Scoop by scoop, bag by bag, an environmental clean-up crew collected tons of oil-soaked sand from Barr Beach south of Mutiny Sands this week.

While no one knows how the oil spill happened, it’s been the bane of property owners nearby for more than two years, sticking to the shoes of beachgoers or the paws of dogs that have who have walked across it.

It has also posed a potential problem for wildlife.

“It’s very toxic to everything around it, so it’s good to get it out of here,” said Carl Andersen, a hazardous materials specialist with the state Department of Ecology’s Spill Prevention, Preparedness and Response Program.

The state is paying a contractor, NRC Environmental Services, approximately $2,500 to clean up the oil. Dwayne James, a home-owner near the spill site, earlier tried to clean it up with his wife Barbara.

“It was nasty. It was a mess,” he said.

He said they hauled out about eight or 10 garbage bags, then had to give up.

“We hadn’t even made a dent,” James said. “It was more than I thought. Once you opened it up, it’s like Pandora’s box.”

At best guess, the oil spill came from an inadvertent release of a ship’s fuel oil; the goopy liquid eventually washed ashore, and was buried and uncovered by the tide ever since. Homeowners near the spill site said it has probably been on the beach two years or so.

Andersen said such “orphan” spills aren’t common.

“It’s actually pretty rare. For a beach clean-up, this is somewhat unusual,” he said.

NRC Environmental Services brought in a couple pieces of heavy equipment to handle the clean-up effort on Wednesday. An excavator scooped the oil-and-sand mixture into Super Sack Containers – white, reinforced plastic sacks capable of carrying 2,200 pounds – while a boom truck stood nearby, ready to pluck the big bags of the edge of the beach.

The soiled sand will be taken to a disposal company in Everett that will cook the oil out of the sand so it can be reused.

James was glad to see the clean-up effort underway. Some residents along the beach reported it in April and had been dogging the state to take action.

“I think it’s wonderful. I wish we had gotten it done earlier, to tell you the truth,” James said.