The PATH Foundation and Lewallen Construction both added $5,000 to the reward money, bringing their total to $10,000.
A $5,000 reward was already being offered by Hawthorne Grading & Hauling of Waleska, Georgia. Carl Hawthorne, spokesman, said the reward will be paid for information leading to an arrest and indictment of the individuals responsible.
The State Fire Marshall's Office has also been brought in to investigate.
Through the state's arson department, a reward up to a possible $10,000, is also being offered as part of standard procedure in arson cases such as this.
"Three pieces of equipment are completely destroyed and one 963 loader will require extensive repairs," Hawthorne said. "Damages to the equipment will be over $400,000 -- not including downtime and loss of profits.
"We are very sad that this has happened and hope that the individuals involved will be prosecuted. Any help in finding these individuals would be greatly appreciated."
Hawthorne's company is a subcontractor for Lewallen Construction, and the damaged equipment was used to construct part of the new portion of the Silver Comet Trail off Hutto Road.
Anyone with tips and other information regarding this crime are asked to contact police.
The contact number for the Polk County Police Department is 770-748-7331.