Wood County officials have held talks with four frac sand companies opening operations here -- CARBO Ceramics, Completion Industrial Minerals, Panther Creek Sand and Northern Frac Sand -- about proposed road usage agreements requiring companies hauling the special type of sand to pay for any excessive damage caused by their trucks. About 100 by the end of 2012 >> Type of business: CARBO Ceramics is a Texas-based manufacturer and supplier of primarily ceramic "proppant" used in the hydraulic fracturing of natural gas and oil wells in the U.S. and worldwide.