An aquifer may be allowed to receive injected wastes where the aquifer meets criteria established in the Environmental Protection Agency 's Underground Injection Control program. The Central Basin aquifer system in Tennessee consists of Ordovician to Devonian carbonate rocks and it occurs from the Valley and Ridge province to west of the Tennessee River. This aquifer system is currently used for drinking water in the Central Basin and western Highland Rim, but is not used for drinking water in the northern Highland Rim nor the Cumberland Plateau provinces. Part of the northern Highland Rim and the Cumberland Plateau, according to the Environmental Protection Agency 's Underground Injection Control criteria, will not be used as a source of drinking water in the future and may be eligible to receive injected wastes. (USGS)