As paving season peaks, getting asphalt to construction sites across Alaska has become more complicated and expensive since Flint Hills Resources closed its North Pole oil refinery.

The reason for the cost increase is asphalt oil used for state Transportation Department Northern Region projects must now be trucked up from Tesoro’s Nikiski refinery.

While work on road projects occurs all summer long, most paving is done in late summer and early fall.

However, preseason fears about Tesoro being able to meet the asphalt needs of the entire mainland of Alaska have been quelled, according to state officials and paving companies. This spring, a Tesoro spokesman said the company would not have a problem meeting the demand.

While supply from Tesoro has not been an issue, Lane Keator, Carlile Transportation System’s Fairbanks terminal manager, said the logistics of the trucking operation from Nikiski have contributed to the cost.

“The biggest challenge is probably maintaining the heat,” Keator said. “It’s loaded hot in Nikiski and it’s a 12-hour, one-way trip minimum from Nikiski to Fairbanks.” Highly viscous asphalt oil is heated to 300 degrees Fahrenheit or more to keep it liquid.

Keator said Carlile and other companies that haul asphalt oil to the Interior now have to pump it into heated tanks once they get to Fairbanks or North Pole, allow it to reheat and then pump it back into the tanker trucks before it is sent to its final destination, which could be as far away as Deadhorse or Eagle.

Luckily, the State of Alaska allows truckers to drive 15 hours per day, as opposed to the 12-hour limit many other states have, he added. However, drivers hauling asphalt north must “start fresh” in Nikiski, he said.

Tesoro has the ability to load about one truck per hour with asphalt oil, and the added demand has required cooperation between dispatch centers to make sure nobody is stuck in line at the refinery, Keator said.