EVERETT — For decades, the Kimberly-Clark plant provided countless jobs in Snohomish County and paper products to millions of people.

Now that it’s closed, the plant is leaving behind another, not-so-positive legacy.

Dioxins — toxic substances thought to cause cancer in humans — have been found in the waterway next to the plant at a level 15 times higher than what the state considers safe. The dioxins in sediment under the water are a result of the bleaching process in making paper.

On land, some petroleum contamination has been found at the 66-acre plant site and under what is now a parking lot south of the plant. Oil companies used parts of the current plant site and the parking lot for petroleum storage and distribution during much of the 20th century.

Click here for a look at what’s on the site now, and what’s next.

Under state law, at some point it has to be cleaned up. Kimberly-Clark officials say pollution was one reason a potential buyer of the plant balked at the deal last year. The sale could have saved nearly half the 700 jobs on the site.

Without a buyer, Kimberly-Clark closed the plant last month, saying it’s difficult to make a profit in the pulp and paper business. The property is up for sale. Most of the pollution was deposited in the bay well before Kimberly-Clark bought the plant in 1995. But under state law, the present owner of a property is liable for the cost of cleanup.

No immediate threat

For several decades, beginning in the 1930s, wastewater from making paper was dumped directly into the East Waterway, an arm of Port Gardner between the Kimberly-Clark plant and Naval Station Everett. The dioxins are believed to have come from chlorine used in the bleaching process and from “sulfate liquor,” which was used to break wood down into pulp.

Dioxins also are thought to have been deposited in Port Gardner through much of the 20th century by ash from smokestacks at mills all along the waterfront.

More dioxins are present in the bay near the Kimberly-Clark plant, however, than anywhere else in Port Gardner, state Department of Ecology officials said.

“The rest of the waterway does not have those high levels,” said Teresa Michelsen, a natural resources scientist for the state Department of Ecology.

The high dioxin levels found in samples taken last year were from sediment at the bottom of the East Waterway, next to the plant. The testing was done for Atlas Holdings, the Connecticut company that considered buying the plant. The company shared the results with the state.

The East Waterway is not open to the public, and the pollution is not considered an immediate threat to human health, environmental officials said. Anyone who eats a fish that’s been in the waterway, however, could be exposed.

More tests of samples from the water and soil will help determine the full extent of the pollution, officials said. Kimberly-Clark plans to demolish all or most of the plant as soon as this summer.

“We still don’t have a complete grasp of everything at the mill site and surrounding properties, as well as the East Waterway,” said Seth Preston, a spokesman for the Department of Ecology. “We’ve got more work to do.”

A cleanup plan could be developed for the parking lot area and plant site as early as next year and for the waterway by 2014, said Andy Kallus, who is in charge of Port Gardner pollution sites for the Ecology Department.

Cleanup of the waterway would likely involve dredging, while contaminated soil on land would be dug out, Kallus said.

No cost has been determined, though it’s safe to say it will be in the millions, Kallus said.

The East Waterway has been on a state cleanup list since 2007. Some cleanup of the waterway has been done through dredging by the adjacent Port of Everett and Naval Station Everett, but there has been no comprehensive project.

“There are a lot of demands and limits associated with cleanups,” Preston said. The state has cleaned up 6,000 sites and still has 5,000 on the list, he said. The sites are ranked by risk to people and the environment.

Surprising levels

The recent test results indicating the presence of dioxins came as no surprise to state environmental officials, who have known for decades that the waterway is polluted.

But the latest round of tests, performed by Hart Crowser, a Seattle environmental firm, showed pollution far more acute than that in samples taken three years earlier by the state.

During negotiations to buy the plant last year, Atlas hired Hart Crowser to take 30 samples of the sediment at the bottom of the bay at varying depths in 15 locations near the plant.

The average dioxin level in the 30 samples was more than 63 parts per trillion. Anything more than 4 parts per trillion is considered potentially unsafe, according to the Ecology Department. Dioxin in the samples ranged from less than 1 part per trillion to 153 parts per trillion.

In addition to dioxins, Atlas also found a coating of wood pulp at the bottom of the bay, which has smothered sea life and created a “dead zone,” Kallus said.

The only other toxic substance found in significant levels was 4-methylphenol, likely generated by the decomposition of wood products and other waste, according to the Ecology Department. Poisoning by 4-methylphenol can cause symptoms that include respiratory failure.

Neither Kimberly-Clark nor Atlas officials have revealed details about the negotiations between the two companies. Atlas had planned to preserve 300 of the 700 jobs at the plant, a union president at the plant said last year. An official with Atlas Holdings did not return calls or emails seeking comment for this story.

Click here to hear the stories of people who worked at the mill.

“It’s fair to say that environmental issues in the East Waterway were a contributing factor in the sale not going forward,” said Bob Brand, a spokesman for Kimberly-Clark, a multinational corporation based in Dallas.

But how dangerous?

Though any immediate threat to the public from the dioxins might be minimal, it will have to be cleaned up, state officials say.

Dioxin is a general term for a group of hundreds of toxic chemicals. They can occur in low levels naturally in the environment through processes such as forest fires.

In their highest concentrations, though, they are unintentional byproducts of industrial processes such as waste burning, chemical and pesticide manufacturing and pulp and paper bleaching with chlorine.

Dioxins accumulate in fatty tissue of animals and can cause reproductive and developmental problems, damage the immune system, interfere with hormones and also cause cancer, according to the World Health Organization.

Dioxins were present in Agent Orange, the defoliant used during the Vietnam War, and were found in the toxic dump at Love Canal in New York in the 1970s. Agent Orange is linked by the U.S. Department of Veterans Affairs to no fewer than 14 diseases, including several types of cancer.

As far as humans are concerned, the threshold of danger for dioxins, set by the federal government, is more conservative than it needs to be, according to David Eaton, a professor of environmental occupational health sciences at the University of Washington.

Eaton, on behalf of the National Academy of Sciences, wrote a report titled “Health Risks from Dioxin and Related Compounds” in 2006. The amount of dioxins found in last year’s sampling is well below thresholds used to guide cleanups in other parts of the country, he said.

“That’s a pretty low number, sitting at the bottom of the bay,” Eaton said. At that level and location, he said, “it’s not a human health problem, it’s potentially an ecological problem and a food-chain problem.”

Eaton was among a group of scientists that recommended to the U.S. Environmental Protection Agency that it set a lower standard, “or if they chose to continue using the more conservative approach, do a better job of justifying it,” he said.

Most of the health effects of dioxins listed by the World Health Organization have been observed through tests on animals, but the correlation is less certain when it comes to humans, Eaton said.

“It’s clearly a very effective animal carcinogen. The human data are less clear, though most scientists believe it’s likely to be a human carcinogen.”

Cleaning up a mess

Eaton said he understands that the environmental standards are set to err on the side of safety.

“That’s basically the way the environmental regulations are written and there’s nothing wrong with that,” he said. “I think it’s important to convey that it’s not something that’s dangerous at this point.”

Still, state law requires that the Ecology Department use standards at least as conservative as those set by the EPA in assigning a danger level to dioxins or any other pollutant, Preston said.

“Our goal is to provide an environment that all aquatic organisms can live in,” said Michelsen, the scientist for the Ecology Department. “We want to get (the East Waterway) to a state where the fish can go back.”

But the cleanup itself, through dredging, could add a new dimension to the problem, Eaton said.

“If you go down and dig it up, you stir it up,” he said.

State officials say many precautions are employed in dredging. Curtains are installed along a boom, hanging down to form a barrier to the spread of the silt, Preston said. The work is also done slowly to minimize spills and is done to coincide with calm tide conditions.

Highly contaminated soil is transferred from a barge to a lined container, then taken by truck and train to a landfill certified to accept hazardous waste, Kallus said. One such landfill is in Arlington, Ore.

Cleaner but unprofitable

The mill was built on Everett’s waterfront in 1931 as Puget Sound Pulp and Timber Co. That company became Soundview Pulp Co. in 1935 and was purchased by Scott Paper in 1951. In recent years, the Everett mill produced Scott Tissue, Viva Paper Towels, Shop Towels and other refined tissue products.

From the 1950s through the 1970s, improvements were made that reduced the level of pollution.

Scott merged with Kimberly-Clark in 1995. Kimberly-Clark then invested about $300 million in the Everett operation. It installed wastewater treatment systems, added a new effluent outfall that takes discharges farther into Possession Sound, and changed the pulp-making system, Brand said.

In 2000, the company changed from a system based on chlorine to one with chlorine dioxide, which, despite the name, produces fewer dioxins. Studies as far back as the 1930s have shown contamination from the effects of sulfate liquor discharges from the pulp and paper mills, he said.

After all that investment, economics prompted Kimberly-Clark to try to sell the operation and, without a buyer like Atlas, close it down.

Former employee Josh Estes, former president of Local 183 of the Association of Western Pulp and Paper Workers Union, believes the plant was economically viable and should not have been closed.

“It’s just a crying shame that 700 employees and their families have to bear the burden of losing their jobs because of environmental issues,” he said.

Bill Sheets: 425-339-3439; sheets@heraldnet.com.