Cookeville Water Hardness & Quality Report (2026)
Water Hardness
4.5 grains per gallon
Source
reservoir
pH Level
6.1
neutral = 7.0
Lead
0.008 mg/L
✓ Below action level
TDS
1450 mg/L
Est. Daily Cost
$0.20
energy & soap waste
Source: See methodology section below · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Cookeville, your appliances are currently losing 10% efficiency due to mineral buildup.
| Appliance | In Cookeville | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 7.1 yrs | 8.5 yrs | -16% |
| Washing Machine | 10.8 yrs | 12 yrs | -10% |
| Water Heater | 12.5 yrs | 15 yrs | -17% |
Regional Water Comparison
How Cookeville compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Cookeville, Tennessee | 76.6 mg/L | 0 ppt | 🟡 Moderately Hard | reservoir |
| Crossville, Tennessee | ≈ 0–60 mg/L | 0 ppt | 🟢 Soft | reservoir |
| McMinnville, Tennessee | ≈ 0–60 mg/L | 3.4 ppt | 🟢 Soft | reservoir |
| Lebanon, Tennessee | ≈ 120–179 mg/L | 0 ppt | 🟠 Hard | reservoir |
| Manchester, Tennessee | ≈ 120–179 mg/L | 86 ppt | 🟠 Hard | reservoir |
National Benchmark
How Cookeville compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Cookeville | 76.6 mg/L | 🟡 Low |
| USA National Avg | 151 mg/L | 🟠 Moderate |
| Scarsdale Top Rated | 0.02 mg/L | 🟢 None |
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What Makes Cookeville's Water Unique?
Local geology and source profile
The City of Cookeville Water Department serves Putnam County, Tennessee, drawing its drinking water supply from Center Hill Lake via Mine Lick Creek. The Cookeville Water Treatment Plant is designed to treat 15 million gallons per day. In 2025, the utility pumped an average daily flow of 12.61 million gallons to customers, maintaining full compliance with all EPA and state drinking water standards across the city's municipal water system.
Cookeville's water originates from surface sources within the Cumberland Plateau watershed, a region characterized by limestone and other mineral-laden rock formations. The geology of the Cumberland Plateau naturally contributes dissolved minerals — primarily calcium and magnesium — to the water supply as it flows through these formations. This setting results in a moderately mineralized supply typical of the region, though hardness varies seasonally with source conditions and treatment processes.
At the moderately soft classification, some scale buildup may occur in water heaters, dishwashers, and washing machines over time. Residents may notice soap scum in showers and reduced detergent efficiency. Regular descaling of water-using appliances and use of water-softening additives in dishwashers can help mitigate effects. In 2025, Cookeville's water met all EPA health standards following 10,143 contaminant analyses; average pH was 7.38 and turbidity averaged 0.04193 NTU, well below EPA limits. Full compliance was reported for lead, copper, and all regulated contaminants. No PFAS data was reported in the available Consumer Confidence Report.
Geology & Source: Center Hill Lake watershed, Cumberland Plateau; limestone and mineral-laden formations contribute moderately mineralized supply — rapid infiltration through less mineral-rich sediments moderates hardness relative to deeper limestone aquifer systems
Other Tennessee Water Reports
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Frequently Asked Questions
Is Cookeville's water safe to drink?
Do I need a water softener in Cookeville?
How does Cookeville compare to the USA average?
Data Sources & Methodology
Water quality data for Cookeville is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.
Water Hardness
Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.
pH
Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.
TDS — Total Dissolved Solids
Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.
PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances
EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.
Lead
Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.
Appliance Lifespan
Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.