ABSTRACT: Underground storage tanks are possible sources of soil and groundwater hydrocarbon contamination. To prevent and safely restore releases of free product requires developed system of rules and regulations. Tennessee State Regulations are based on Federal Regulations and are adjusted to Tennessee State conditions, with the guidelines and reimbursement costs lists. The owner/operator of facility, where the free product release appeared, have to inform Tennessee Department of Environment and Conservation (TDEC), Division of Underground Storage Tanks immediately. TDEC provides owner/operator with instructions, that have to be done. To detect contamination levels, soil and groundwater sampling have to be performed and soil and groundwater analyses obtained from the TDEC approved laboratory. The contracted company receives the money for prepared report from the owner/operator of the investigated site. The owner/operator is responsible for costs on his/her own till they reach $10.000. The costs above $10.000 are reimbursable, but only if TDEC considers them to be spent reasonable.