Chris Caskey, The Union Democrat

Spilled fuel from a tanker truck that crashed in last week's snowstorm will take another week of work and road closure to clean up.

Crews will be working through at least Sunday to clear the remainder of contaminated earth and repair parts of Highway 108/120 west of Jamestown. Because of the work, the three-mile stretch of highway between the Montezuma Road Junction and Yosemite Junction will close every day from 7 a.m. to 5 p.m.

Motorists will be re-routed through Chinese Camp during the closure, which Caltrans spokeswoman Angela DaPrato said on Monday will add about 10 minutes in delays. The road will open to traffic outside of those work hours, DaPrato said.

"They thought it was smaller than it actually was," she said of the initial evaluation of the contamination.

The big rig carrying gasoline overturned early Wednesday morning, the day after a cold storm brought low snow to the Mother Lode causing havoc on the roadways.

The truck was initially thought to have spilled about 1,000 gallons, but DaPrato said that estimate grew to about 1,800 gallons after the tanker was removed and crews discovered the fuel had seeped further into the surrounding soil than first thought.

The cleanup work will include removing the contaminated soil and replacing it with new material including underneath the existing roadway, DaPrato said.

The heavily travelled stretch of highway has been closed since the crash, and work crews were on the scene over the weekend for what was supposed to be the final cleanup effort.

Tuolumne County is leading the cleanup with hazardous materials equipment, and the California Highway Patrol is handling traffic control. DaPrato said California Fish and Game and Department of Water Resources have also monitored the site since the spill.

Also on the scene is a crew from Apex Envirotech, a Sacramento area firm that handles environmental cleanup.

Apex Envirotech ownerTom Landwehr said three factors have made this job more difficult than a typical cleanup. It took "longer than normal" to move the tanker truck on Wednesday, which ultimately led to an increase in the size of the spill. He also said they found unknown infrastructure like a clay irrigation pipe and an abandoned well after starting, which complicates the containment efforts.

"There's a lot of old stuff there that was in that area," Landwehr said on Monday.

DaPrato said Caltrans is taking the cleanup "day-by-day," and she noted Sunday is an estimate for completion and could change.

"They're doing a thorough job," DaPrato said.