Five people were hurt in the Feb. 23 construction site explosion at the Alderwood Water and Wastewater District plant along Picnic Point Road, between Edmonds and Mukilteo.
It caused more than $1 million in damage.
The explosion was investigated by the state Department of Labor and Industries.
The state found a subcontractor at fault in the accident. The investigation found no violations by the site's general contractor, Kennewick-based Apollo Inc.
On Aug. 21, the state levied $40,400 in fines for three violations by Ferrellgas, a national propane supply company, according to the L&I report obtained by The Herald.
Investigators found that a Ferrellgas manager reportedly gave unsafe orders while an employee was using a crane to move the propane tank.
Ferrellgas plans to appeal the findings, spokesman Scott Brockelmeyer said Tuesday from company headquarters in Kansas.
"We've reviewed it, and we disagreed with some of the conclusions they came to," he said.
At the time of the explosion, the 1,000-gallon tank contained 300 gallons of propane.
The load shifted as it was being moved, shearing off a valve and exposing the propane.
Large, partially filled propane containers are considered "dangerously unstable" due to the weight of the liquid sloshing around inside, L&I investigators wrote. That understanding is written into state and federal laws and fire-safety codes.
Moving big, partially filled propane containers with a crane or bucket truck is considered "extremely dangerous and should be avoided if at all possible," the report says.
There are commonly known ways to limit the danger of such operations, but none were employed at the plant, L&I said.
The company's accident prevention program also didn't include required training for that kind of task.
The violation led to a $36,000 penalty.
L&I also found two lesser violations that still were considered serious.
According to the report, Ferrellgas employees did not use rope to secure the tank while it was suspended by the crane. That's required by law to keep a load from moving and hitting people or property. The fine for that offense was $3,600.
L&I also determined that the crane operator didn't properly deploy its stabilizing equipment. The resulting imbalance could have tipped the crane over and caused the driver serious injuries or even death, investigators said.
The fine for that infraction was $800.
Efforts to double sewage treatment capacity at the plant has been under way since 2008. The project is expected to be finished this fall.
Rikki King: 425-339-3449; firstname.lastname@example.org
More Local News Headlines
4 killed when truck leaves road, lands in pond in Tulalip 1:36 p.m. Man shakes depression, anxiety in 3,000-mile walk to daughter in Lynnwood 'Hallelujah': Man's stolen ashes returned to Snohomish family Inmate fight leads to prison lockdown; minor injuries 11:09 a.m. Some county school districts excel, others struggle in Common Core testing ‘Stihl book’ burglar gets 19 months and drug treatment Inslee presses lawmakers on ed funding plan in light of new sanctions Suspect held for package thefts in Mill Creek
Our new comment system is not supported in IE 7. Please upgrade your browser here.