After tank implosion, WA expands scrutiny to other paper mills
State officials are launching what will likely be monthslong inspections of several pulp and paper mills following the deadly tank rupture at the Nippon Dynawave Packaging plant.
The state Department of Labor and Industries announced Thursday that it plans to scrutinize two paper mills that use the same caustic chemical that killed 11 workers at the Longview mill in May. State officials will audit several safety factors - including tank conditions and maintenance practices - at Smurfit Westrock in Longview and Port Townsend Paper Company in Port Townsend.
In a news release announcing the inspections, the state mentioned no problems at the two mills. L&I Director Joel Sacks called the probes precautionary, proactive steps for worker safety at Washington's paper mills in the announcement.
Investigators will also inspect seven other paper plants that don't use the chemical, called white liquor, but store and use other potentially hazardous substances.
L&I is already weeks into its investigation of Nippon Dynawave.
During the new inspections, which Labor and Industries says could take up to six months, investigators will review mill safety plans, hazardous chemical assessments, training materials and more. They'll also hold interviews and survey mills in person.
Nippon Dynawave has faced intense scrutiny since an aboveground tank capable of storing around 900,000 gallons of chemicals failed. Federal and state agencies have launched separate investigations into what caused the industrial disaster.
A valve connected to the same tank sprung a leak in late 2023, but mill officials delayed its repair for at least 10 months - a fact revealed in state environmental records released last week. The valve is key to preventing the tank from overpressurizing.
It isn't clear whether Nippon Dynawave fixed this particular valve before the implosion in late May. The state records offered the public only a limited glimpse into the tank's condition.
No state agencies are responsible for regularly inspecting this type of storage tank; that responsibility falls on the tank's owner.
Following the fatal chemical spill at Nippon Dynawave Packaging in Longview, The Seattle Times is reporting on the paper and pulp mill industry. If you have any experience in the industry - whether working in a mill, in management, at a regulatory agency or in another capacity - we would like to hear from you.
Do you have information that we should consider investigating? You can reach our investigative team a few ways. You can email us at investigations@seattletimes.com or if you want to send a tip securely, visit our secure tips page.
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This story was originally published July 2, 2026 at 4:50 PM.