On Sunday, April 12, a 3.3 magnitude earthquake rumbled the town of Cushing, OK.
This low-magnitude tremor certainly wasn’t the first to hit Oklahoma in recent months — or even that day.
According to Oklahoma City’s News 9, the Cushing earthquake was the eighth earthquake above a 2.0 magnitude to take place that Sunday throughout the state. Many experts believe hydraulic fracturing is one reason for earthquakes being more common than ever before in Oklahoma.
But in Cushing, a town of 8,000 people that is also a known hub of above ground storage tanks that contain 87 million barrels of crude oil, the threat of earthquakes has more potential consequences here than anywhere else in the state. If an earthquake of a high-enough magnitude were to hit and create leaks in these tanks, the effects and devastation of the resulting spill would be significant.
Dr. Riki Ott, an activist for energy transportation reform, told the Independent she sees glaring similarities between the Exxon Valdez spill and the current state in Cushing.
“It has all of the ingredients for a major disaster,” she said. “Government and industry officials are misleading the public and hardly anyone knows about it.”
While the drastic increase in earthquakes in Oklahoma is alarming, many reasons abound to make the Cushing situation different and much less potentially horrific compared to the Exxon Valdez spill. First, these field erected tanks have multiple defenses against spills and leaks. The API 650 standard for construction of above ground storage tanks specifically addresses constructing tanks to be able to withstand earthquakes.
Storage tank owners are also required to have some sort of secondary containment to contain the tank product if a leak or breach in the primary containment occurs. This secondary containment can take the form of a double wall tank, internal pvc liner, or a dike.
Second, the tanks are on land as opposed to over water as in the Exxon Valdez spill. While tank owners and environmentalists alike want to avoid and cringe at the thought of chemicals being released into the environment, a spill on land is easier to contain than a water spill. Hopefully with the safeguards built into tank systems, this comparison never has to be conducted in real life.
With many government experts saying it’s not a matter of if, but when, a major earthquake hits Oklahoma, the need for increased awareness among storage tank owners and operators is clear.
If an earthquake occurs, an immediate visual inspection of the tank should be completed to look for any cracks or shifting in the tank’s foundation. A weekly visual tank inspection by walking around the tank, looking for any change in the tank’s exterior should also be conducted to observe potential changes in the structure of the tank over time.
Taking these simple steps will help you as a steel storage tank owner to prevent or quickly address issues caused by the increasing earthquake activity in Oklahoma.
Do you think the increasingly-frequent earthquakes throughout Oklahoma will harm field erected tanks throughout the state? Or do you think these steel storage tanks will be able to withstand their impact? Share your thoughts with us about earthquakes and above ground storage tanks in the comments below.