35 ILCS 200/11-45

To determine 33 1/3% of the fair cash value of any low sulfur dioxide emission coal fueled device, the Department shall determine the net value which could be realized by its owner if the device were removed and sold at a fair, voluntary sale, giving due account to the expense of removal, site restoration, and transportation. That net value shall be considered to be 33 1/3% of fair cash value.