The cause and origin of the explosion at Midwest Industrial Asphalt is being described as a gauge malfunction within the tank where the explosion and ensuing fire occurred.
Steve Mathy, president of ALM Holding Co., which acts as the parent company to Midwest Industrial Asphalt said the operator was following protocol when the explosion happened.
"The operator checked the gauge inside the tank, which indicated there was two feet, two inches of product," he said. "He then proceeded to draw a sample, since the gauge indicated the sample port was submerged in the liquid."
When the operator attempted to draw a sample, nothing came out of the port. He then lit a torch to unclog the port, when vapors were ignited and traveled through the port into the tank where the explosion occurred.
Mathy said the gauge was not submerged within the asphalt and diesel fuel mixture inside the tank and was in fact exposed.
Midwest Industrial Asphalt said it has torn down the destroyed E-2 tank and plans to rebuild.
Mathy also said the company is looking into newer and more advanced gauges as well as alternative heating sources, such as steam, for any potential clogs in the sample port.The investigation into what caused a storage tank explosion at Midwest Industrial Asphalt continues almost one week after the incident.