Contamination of a waterway flowing through Dunsmuir's Tauhindali Park and into the Sacramento River is believed to have come from the freeway.

Contamination of a waterway flowing through Dunsmuir's Tauhindali Park and into the Sacramento River is believed to have come from the freeway.

Diesel fuel spilled on a lane of Interstate 5 weeks ago flowed down a storm drain above the park and emptied into a stream in the park, said Rick Dean of Siskiyou County Environmental Health.

"I found an intermittent sheen, like oil, on the surface of the water," he said Friday, referring to his April 16 visit to the park. "It was coming from a culvert between the two bridges. A northbound lane of I-5 is actually where the entrance is for that culvert."

He said he found an old stain on the asphalt around the storm drain. He didn't know how old the stain was or what exactly caused it.

Dean also said clean up efforts are in progress.

"I called Ron that evening," he said, referring to Dunsmuir public works supervisor Ron LaRue. He said LaRue laid boom – absorbent padding designed to pick up petroleum – at the opening to the culvert in the park.

Ten sheets of boom still floated in the water Friday.

LaRue said the boom will stay there until the next rain, when more diesel might get washed down the culvert into the park.

When LaRue was notified of the contamination, he found the source of the spill on the freeway.

"It was about 100 yards past the bridge," he said. "Some vehicle had pulled off on the right shoulder."

The stain ran back downslope and into a drain inlet, LaRue said. He identified the fuel as diesel, stating, "I picked up a handful of dirt soaked with the stuff and smelled it."

"Caltrans has contracted with Ben's Trucking, out of Red Bluff," said Dean. "They will clean up top, clean the whole culvert, and get the residual oil out of the water."

Ben's Truck and Equipment would not confirm the contract, citing company policy regarding liability.

A request for information from Caltrans was not answered by press time.

The incident became known after Dunsmuir resident Rami White smelled what she thought was gasoline in the park as she crossed a footbridge during a regular walk with her nine year old son, Jay.

"It was really pretty bad," she said Friday. "It gave me a headache and my nose was burning."

White said there were a lot of dead worms lying at the bottom of the stream. She called the California Environmental Protection Agency, and sent them photos she shot with her phone.

White also called Dunsmuir Recreation and Parks and the River Exchange, she said.

River Exchange Administrative Director Robin Singler said she was the person who contacted the county's environmental health department.

"We got another call from a citizen about it," she said Friday. "She was concerned about dogs licking it up or something."

Friday, two weeks after she reported it, White revisited the stream where she found the spill. There was no smell of petroleum in the air, and the water looked clear at first glance. White picked up a stick and jabbed it into the steam bed. A rainbow sheen of oil appeared on the surface of the stream and flowed toward the river.

Dunsmuir city manager Brenda Bains said Monday she hadn't heard of the incident. She asks the public to report incidents like this in the future directly to city hall.