Efforts Underway to Contain and Mitigate Chemical Release After Longview Mill Explosion

Complex cleanup and recovery efforts are underway in the aftermath of an implosion at a Longview pulp mill that has likely killed 11 people and led to the release of hundreds of thousands of gallons of chemicals into the environment.

The city of Longview’s drinking water source has been protected from the contamination, and air quality monitoring has not identified hazards to human health, officials said at a Thursday afternoon news conference near Nippon Dynawave Packaging Co.'s mill.

But risks remain as the cleanup focuses on preventing any more contamination and diluting any spilled chemicals into the Columbia River.

The tank that ruptured Tuesday at the mill had the capacity to hold 900,000 gallons of caustic chemicals known as “white liquor” used to break down wood chips in the process of making pulp. It released a “high pH caustic liquid” through a storm drain and into a ditch that is connected to a drainage network that moves through the community of Longview, said Brooks Stanfield, the on-scene coordinator with the U.S. Environmental Protection Agency.

“It literally runs through people's backyards, people have access to it, dogs can swim in it,” Stanfield said at the news conference. ”It's obviously something where there is a risk for people to come in contact with that liquid if we don't prevent them from doing so.”

Cleanup responders identified elevated pH levels in the ditch, mostly near the stormwater outfall near the facility, but over time they saw it migrating through the drainage system, Stanfield said. The top priority has been protecting the city of Longview’s drinking water source from the contamination. The ditch sits on top of the aquifer and well field the city relies on.

Officials say they have been drawing fresh water from the Cowlitz River, to dilute and flush the contaminated water. That diluted water is being released in the Columbia. The last report from the two points the water is being discharged into the Columbia recorded pH levels of 7 and 8.5. Officials are aiming to keep the level below 9 pH. The baseline pH for the Columbia River is about 7, according to Stanfield.

A liquid with high pH is deadly to fish, Stanfield said, and responders have observed some dead fish in the ditch network. A little bit of white liquor reached the Columbia River in the initial hour after the implosion, Stanfield said, but that outflow where that white liquor was released was immediately shut off.

Officials have found redside shiner and carp that died in the ditch system. No other fish or wildlife impacts have been documented, said Scarlet Tang, a spokesperson with the state Department of Ecology.

Stanfield says it is safe to swim and fish in the Columbia and there are no health warnings or advisories at this time.

Residents may notice an odor released through off gassing as the water is flushed, said Longview Public Works Director Chris Collins. Cleanup responders are monitoring for the release of hydrogen sulfide, volatile organic compounds and sulfur dioxide as the water is being flushed.

After the fatal implosion, those working to clean up and investigate the site likely face the biggest risks of exposure to the chemicals, said Marissa Baker, director of the Industrial Hygiene Program at the University of Washington.

White liquor is extremely hazardous. If it comes in contact with skin, it can burn you “instantly, aggressively, to the bone,” Baker said.

The Cowlitz Indian Tribe, Yakama Nation, EPA, state Department of Ecology and other state, local and federal agencies are participating in the response.

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