Tesoro Corp. should resume asphalt distribution on June 11, about a week later than originally planned.

Tesoro, the only producer of asphalt in the state, ran out of the material May 12, which caused work on potholes and other road projects to come to a halt.

The production will resume after the arrival next week of a shipment of heavy crude oil, Tesoro spokesman Nathan Hokama said yesterday.

Asphalt is produced from heavy crude oil. When heated and mixed with crushed rock, called aggregate, it can be used to build roads, driveways and parking lots and to fill potholes.

Tesoro said last month that it planned on having asphalt ready for contractors by about tomorrow.

The shortage caused problems for local asphalt contractors and others who pave roads and are fixing potholes that were caused by heavy rains during February and March.

Tesoro announced May 18 that it will spend almost $1 million to upgrade its liquid-asphalt storage capacity as it responds to a shortage of the petroleum byproduct in the Islands. By August, the reconfigured refinery tank capacity will let Tesoro store a 50-day supply of asphalt.

Chevron Hawaii used to produce about half the state's asphalt but, facing federal deadlines to produce lower-sulfur gasoline and diesel fuel, decided last year to switch to a lighter crude oil with less sulfur. The new crude isn't appropriate for making asphalt, and Chevron said in December it would stop making the material.

Reach Sean Hao at shao@honoluluadvertiser.com.