After a 10-month wait, preliminary work began Thursday on the delicate task of removing barrels sitting in Wallowa Lake marked as containing defoliants used in Agent Orange.

A contractor working for the U.S. Environmental Protection Agency started exploring the alpine lake’s bottom with side-scan sonar to learn more about what’s actually there.

The operation is in its early phases. A spokeswoman for the Oregon Department of Environmental Quality said work would continue for several days. Removal could begin Saturday, she said.

Also on Thursday, officials announced that the eastern Oregon town of Joseph, which draws its drinking water from the lake, had switched over to a backup well that it will continue using while the recovery continues.

#Wallowa Lake Update ** @EPAnorthwest w/ @OregonDEQ plan to test and remove 12 100-gallon drums, labeled as herbicides. We’re using a Remotely Operated Vehicle to survey the sunken drums before we can safely remove them. https://t.co/F0orlg2DPM pic.twitter.com/NwNxeN7q8A — U.S. EPA Region 10 (@EPAnorthwest) June 13, 2019

The barrels could be sitting in water that’s between 90 and 140 feet deep, said the department spokeswoman, Laura Gleim. She said the depth, combined with the lake’s icy deep-water temperatures and 4,300-foot elevation, may complicate recovery. If the barrels are 90 feet down, Gleim said, a diver could only spend about five minutes -- possibly longer -- in a dive there. At 140 feet, divers may not be able to reach the site, she said.

A remotely operated vehicle is scheduled to reconnoiter the site on Friday.

Last August, recreational divers discovered barrels labeled as containing one of two defoliants -- 2,4-D or 2,4,5-T. Combined, the two chemicals were once known by another name: Agent Orange. The herbicide was used extensively in the Vietnam War and has been connected to numerous illnesses among veterans and civilians who were exposed.

State and federal authorities moved slowly after the discovery in Wallowa Lake. Their plodding response to what could be toxic herbicides in the town’s drinking water supply left residents wondering what could possibly be taking so long.

Joseph has previously tested its drinking water for 2,4-D, the less toxic of the two chemicals. None has been found since testing started in 1984.

But no sampling had been done for 2,4,5-T, a toxic herbicide unavoidably contaminated by dioxin during its manufacturing. Water tests for the chemical were done earlier this week.

Though the results aren’t back yet, state health officials on Thursday advised that lake visitors “may continue with normal activities until further notice.” Wallowa Lake is a popular summer tourist destination for swimmers and boaters.

Residents said they were relieved to know authorities were finally taking the threat seriously. But some questioned why the Oregon Health Authority would say the lake was safe without having the test results to prove it.

“It doesn’t sound right to me,” said Meg Bowen, who lives in Joseph and frequently kayaks and paddles a dragon boat in the lake. “We are not going to be in the lake until we get the results of the tests. That just seems prudent to me.”

It isn’t known where the barrels came from or whether they contain what the label says they do. But authorities say they believe the drums are intact.

— Rob Davis

rdavis@oregonian.com

503.294.7657; @robwdavis

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