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L&I News: Tesoro refinery investigation

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Tesoro files appeal of record $2.39 million citation

Oct. 22, 2010

Tesoro filed its appeal today of the record $2.39 million citation the Department of Labor & Industries issued against the company in the wake of the fatal refinery explosion that killed seven workers. Read full story

L&I issues record fine in deadly Tesoro explosion

Oct. 4, 2010

After a six-month investigation, the Department of Labor & Industries has concluded that the deadly explosion at the Tesoro petroleum refinery in Anacortes could have been prevented. Read full story

Tear down begins of damaged heat exchanger

May 14, 2010

Crews have begun to dismantle the heat exchangers involved in the deadly April 2 explosion at the Anacortes Tesoro Refinery as the investigation continues into the incident that killed seven Tesoro employees.

The dismantling work began on May 10 with the top section of the heat exchangers scheduled for removal on May 15. Some of the work was observed by Michael Silverstein, Assistant Director of L&I’s Division of Occupational Safety and Health (DOSH), and David Puente, DOSH Statewide Compliance Manager, who toured the site on May 13 and viewed the dismantling process.

L&I inspectors have spent the weeks since the explosion interviewing Tesoro employees and managers and reviewing documents related to operations of the facility. Access to the area of the refinery plant where the blast occurred had been limited due to asbestos in the area and concerns that the structure supporting the heat exchangers was damaged and unsafe.

Last week, Tesoro, L&I, and the U.S. Chemical Safety Board, which is conducting its own investigation into the explosion, agreed to a detailed and complex plan that allows for the heat exchangers to be dismantled in such a way as to preserve the evidentiary value of the machinery.

Each step of the dismantling process has been planned with hold points allowing L&I investigators to observe the progress of the work and inspect the machinery. The dismantling work will be done in 14 individual segments, known as “lifts.” The entire deconstruction process is estimated to take three to four weeks to complete. Once the heat exchangers are dismantled, the heat exchanger that ruptured will be packed and shipped to a laboratory for testing as part of the investigation.

The explosion at the Anacortes refinery is Washington’s deadliest industrial disaster in the 37 years that L&I has been enforcing the state’s workplace safety law, the Washington Industrial Safety and Health Act, (WISHA).

Investigation expands as asbestos cleanup continues

Seventh Tesoro worker dies

April 26, 2010

The Department of Labor & Industries has opened inspections of two contractors who serviced the heat exchangers involved in the deadly explosion at the Anacortes Tesoro Refinery April 2.

Matrix Service Inc. of Tulsa, Okla., was retained by Tesoro to unseal the heat exchangers and reseal them, while Coastal Industrial Services Inc. of Ferndale was responsible for pressure washing the vessels once they were open. The explosion at Tesoro came after the heat exchangers had been cleaned. The inspections of the two companies involved are a routine step in the overall L&I investigation.

Seven men and women, all employees of Tesoro, died as a result of the explosion. It was the deadliest industrial accident in the 37 years L&I has been enforcing the state’s workplace safety laws under the Washington Industrial Safety and Health Act (WISHA). 

In other recent developments, asbestos cleanup of the site surrounding the blast area continues, but it is now estimated to be another week before L&I inspectors can enter the area freely and safely.

Investigators have had limited access to the blast site because asbestos used in refinery piping was scattered by the explosion and damaged piping continued to shed asbestos in the area. While the asbestos cleanup proceeded, crews had hoped to remove mangled scaffolding around the heat exchangers and erect new, stable scaffolds so investigators could examine the damaged machinery.

However, structural engineers are concerned there may be no safe way to erect scaffolding around the heat exchangers because supports holding the machinery in place may have been extensively damaged in the explosion. Instead, crews may have to dismantle the heat exchangers in phases so inspectors can examine them as they are deconstructed. A plan to do this is currently being developed.

In the meantime, L&I inspectors have continued interviewing employees and managers and reviewing documents related to operations of the facility. Tesoro has provided a trailer at the refinery for the use of the investigation team.

Members of the Chemical Safety Board, which is also investigating the incident, have left Anacortes and plan to return when access to the site of the explosion is available.

Asbestos limits access to refinery

Disaster death toll climbs to six

April 13, 2010

Ongoing asbestos clean up at the Tesoro refinery continues to hamper access for Department of Labor & Industries inspectors investigating the April 2 explosion, and it is now expected to be two weeks before they are able to examine the heat exchanger that ruptured and the surrounding blast area.

On April 13, L&I also learned that a sixth worker died as a result of the Tesoro refinery disaster -- as many as died in the 1998 Equilon refinery blast. The two are the deadliest industrial accidents since L&I began enforcing the Washington Industrial Safety and Health Act (WISHA) in 1973.

A seventh Tesoro worker remains hospitalized due to injuries sustained in the blast.

Investigators have had limited access to the blast site because of asbestos, used in refinery piping and scattered by the explosion. Some damaged piping has continued to shed asbestos, further contaminating the area.

Abatement crews will need time to remove the asbestos safely, as well as some of the damaged piping. In addition, there had been scaffolding surrounding the heat exchangers. This scaffolding was mangled by the blast and also contaminated by asbestos. Crews plan to remove the scaffolding and erect new scaffolding, which will give L&I inspectors an opportunity to make a close examination of the damaged heat exchangers.

The scaffolding will have tarps to protect the area from wind and rain.

While the cleanup at the work site proceeds, L&I inspectors will continue interviewing employees and collecting pertinent documents.

The investigation team has grown now to six inspectors and a compliance manager. The additional inspectors each bring specific expertise and may be involved in just a portion of the overall investigation, which is expected to take a full six months from the date of the disaster.

Interviews, meetings as Tesoro refinery investigation begins

April 9, 2010

TUMWATER - The Department of Labor & Industries continues to investigate the deadly explosion at the Tesoro petroleum refinery in Anacortes, more than one week after the incident which claimed the lives of five workers and badly injured two others.

The L&I’s Division of Occupational Safety and Health (DOSH), which investigates all workplace fatalities, was notified of the event at 2:06 a.m. April 2, approximately 90 minutes after the incident.

On Saturday, April 3, the team of inspectors was able to enter the area of the explosion and begin the difficult task of reconstructing what led to the event. Asbestos scattered around the area of the blast forced the team to temporarily halt their on-site investigation while an abatement team removed the asbestos.

But the investigation proceeded, with the team beginning the process of interviewing company employees and officials and collecting pertinent documents.

On Monday, April 5, DOSH officials, including Assistant Director Michael Silverstein and statewide Compliance Manager David Puente, visited the L&I inspectors conducting the investigation and toured the site of the explosion.

They also met with officials from the U.S. Chemical Safety Board (CSB), which has also sent a team from Washington, D.C., to investigate the incident at Tesoro.

The officials wrapped up their day by meeting with members of the United Steelworkers, which represents Tesoro employees, to explain the process involved in investigating a workplace fatality.

Tuesday, Silverstein and CSB members met with U.S. Rep. Rick Larsen, who represents the area where Anacortes is located, to brief him on the status of the investigation and their respective roles investigating the explosion.


This event is the worst industrial accident in Washington state since a similar explosion in 1998 at the Equilon refinery in Anacortes killed six workers.

Refinery facilities and operations are complex and technical. The L&I investigation team includes well-qualified experts in the field of Process Safety Management, which is a set of federal and state regulations governing production facilities that work with highly hazardous materials.

The investigation into the Tesoro explosion will be thorough and could take up to six months to complete. As a regulatory body, the L&I team will not only work to determine what led to the incident, but also whether the employer violated any workplace safety rules that may have been a factor in the incident.

L&I investigations typically involve interviewing many people and reviewing many records and processes. For context, L&I’s investigation of the 1998 Equilon refinery explosion produced 20,000 pages of documents.

L&I has previously inspected Tesoro in 2009 as part of a federal effort to inspect all petroleum refineries in the United States, referred to as a National Emphasis Program (NEP).

Following that inspection, L&I cited Tesoro for 17 “serious” violations and issued a fine of $85,700. The company appealed. A settlement agreement reached in November 2009 called for L&I to set aside 14 of the violations and reduce the fine for the remaining violations to $12,250. In exchange, Tesoro agreed to retain a third-party consultant to review the hazards L&I alleged in its original inspection, and abide by any recommendations the consultant makes to correct the hazards.

Other Washington state refineries

As part of the NEP, L&I has also inspected two other Washington state refineries and is currently inspecting a third.

U.S. Oil in Tacoma was cited for 15 “serious” violations and 5 general violations and fined $18,200. The company paid the fine in full and corrected all the hazards.  

Shell Oil Co.’s Equilon refinery in Anacortes was cited for 26 “serious” violations and fined $109,600. The company has appealed the citation.

An inspection of BP’s Cherry Point refinery in Blaine is currently under way.

Media Contact: Hector Castro,, 360-902-6043

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