Hardest Water in Tennessee
20 cities ranked by water hardness. Collierville tops the list at 180 PPM.
Tennessee's water hardness varies significantly by city and water source. The state average across our database is 96 PPM, which is moderately hard. Some cities need treatment while others do not. 40% of cities we track in Tennessee have hardness above 120 PPM.
Collierville has the hardest water at 180 PPM (10.5 GPG). At this level, expect visible scale on faucets, reduced water heater efficiency, and higher soap usage. A salt-based water softener can pay for itself over time in energy and consumable savings, though the payback depends heavily on your hardness and whether you heat water with gas or electricity. Estimate your payback. Johnson City has the softest water at just 15 PPM. No softener is needed.
| # | City | PPM | GPG | Level | Softener? |
|---|---|---|---|---|---|
| 1 | Collierville | 180 | 10.5 | Very Hard | Yes |
| 2 | Murfreesboro | 161 | 9.4 | Hard | Recommended |
| 3 | Franklin | 161 | 9.4 | Hard | Recommended |
| 4 | Clarksville | 140 | 8.2 | Hard | Recommended |
| 5 | Cookeville | 140 | 8.2 | Hard | Recommended |
| 6 | Brentwood | 135 | 7.9 | Hard | Recommended |
| 7 | Columbia | 120 | 7 | Hard | Recommended |
| 8 | Old Hickory | 120 | 7 | Hard | Recommended |
| 9 | Smyrna | 115 | 6.7 | Moderately Hard | Optional |
| 10 | Nashville | 110 | 6.4 | Moderately Hard | Optional |
| 11 | Hendersonville | 105 | 6.1 | Moderately Hard | Optional |
| 12 | Knoxville | 90 | 5.3 | Moderately Hard | Optional |
| 13 | Chattanooga | 82 | 4.8 | Moderately Hard | Optional |
| 14 | Jackson | 57 | 3.3 | Slightly Hard | No |
| 15 | Knoxville West | 55 | 3.2 | Slightly Hard | No |
| 16 | Germantown | 35 | 2 | Slightly Hard | No |
| 17 | Chattanooga Downtown | 35 | 2 | Slightly Hard | No |
| 18 | Memphis | 33 | 1.9 | Slightly Hard | No |
| 19 | Maryville | 25 | 1.5 | Slightly Hard | No |
| 20 | Johnson City | 15 | 0.9 | Soft | No |