Valley Center ? Workers at the Barton Solvents plant have begun cutting up and removing large storage tanks destroyed in an explosion that forced the evacuation of the entire town earlier this summer.

“Moving forward, there is a great deal of work to be done, but this is an important next step for all of us,” David Casten, president of the Des Moines, Iowa-based company, said Thursday of the new cleanup phase.

A tanker truck was pumping naphtha, a liquid derived from crude oil that’s used as a raw material in the petrochemical industry, into a 15,000-gallon tank on July 17 when an explosion caused a large fireball. The fire and explosions ignited about 660,000 pounds of chemicals, prompting the widespread evacuations in the community of 6,000 just north of Wichita.

The state fire marshal’s preliminary finding was that static electricity built up in the tank being filled and sparked the explosion.

Randy McClure, an investigator with the U.S. Chemical Safety and Hazard Mitigation Board in Washington, D.C., said the board investigation into the explosion was continuing. The board, an independent federal agency that investigates industrial chemical accidents, is still performing analysis of equipment at the site, McClure said.

He said the investigation would likely take a year.

But federal investigators have given the company permission to move the equipment aside and begin dismantling and removing the tank farm debris. The Kansas Department of Health and Environment is supervising the work at the tank farm site, which includes about 40 storage tanks with a capacity of about 600,000 gallons.

The board looks at what procedures a company has, how well they were followed, if they were in accordance with best practices in the industry, and whether a lack of regulations may have contributed to the incident.

“We really do sift through things with a very fine-toothed comb,” McClure said.

The idea, he said, is to see if changes can be made to help prevent similar incidents.

Among the issues the board has been looking at is whether the configuration of the storage tanks contributed to the spread of the explosions and fire.