Smyrna Water Hardness & Quality Report (2026)

Smyrna, Tennessee, in Rutherford County southeast of Nashville — one of Tennessee's fastest-growing communities, a major auto industry hub (Nissan's largest North American manufacturing plant is in Smyrna, opened 1983), Smyrna Airport, and a rapidly expanding Nashville metro southeast suburb with a growing diverse workforce community — draws its municipal water supply from the Stones River and Percy Priest Lake via the Town of Smyrna Water Division. Water hardness in Smyrna measures 190.5 mg/L — classified as hard.

Smyrna's hard supply reflects the central Tennessee calcareous dolomite platform. The Stones River watershed above J. Percy Priest Lake drains: Rutherford County Ordovician Knox Group dolomite (the major calcareous formation of middle Tennessee — massively calcareous dolomite subcropping across central Tennessee); the Mississippian Warsaw Formation limestone (highly calcareous marine limestone of the Tennessee Interior Low Plateaus Province); and the Tennessee Central Basin (Ordovician–Silurian calcareous dolomite platform — the Nashville Dome's exposed calcareous core). The Knox Group dolomite and Warsaw Limestone calcareous terrain produce the hard 190.5 mg/L at Smyrna.

At 190.5 mg/L, Smyrna residents face regular hard water challenges. Scale deposits form on faucet aerators, showerheads, and appliances within weeks — monthly descaling with citric acid solution is standard maintenance. Town of Smyrna Water Division consistently delivers water meeting all Tennessee TDEC and EPA Safe Drinking Water Act requirements.