Is Knoxville, TN Tap Water Safe to Drink?
Yes, Knoxville tap water is safe to drink. Hardness is low at 90 PPM, and no contaminants exceed health guidelines. Most homes here don't need treatment.
Hardness Scale: Where Knoxville Falls
0Slightly
60Moderate
120Hard
180Very Hard
250Extreme
400+
How Knoxville Compares
Knoxville's water is 35% softer than the national average of 138 PPM - ranking in the bottom 58% for hardness nationwide. Most homes here do not need a softener. Within Tennessee, it ranks #12 of 20 cities (6% below the state average of 96 PPM). Among large cities (200k-500k), Knoxville ranks #94 of 165 for hardness.
What Knoxville's Water Means for Your Home
Hardness: 90 PPM - Low Concern
Knoxville's water is moderately hard at 90 PPM. You'll see some spotting on glassware and a film on shower doors over time, but it's not the kind of hardness that demands a full softener. A salt-free conditioner is worth considering if you have a tankless water heater or high-end fixtures.
Contaminants & Safety
Disinfection byproducts are the notable finding here. Knoxville's water has TTHMs at 40.8 ppb and HAA5 at 30.1 ppb — both within legal limits, but the EWG health guidelines are far stricter. These byproducts form when chlorine reacts with organic matter during treatment. A whole-house activated carbon filter reduces both chlorine and its byproducts. Want the full picture? Request your utility's annual Consumer Confidence Report.
What's in the Treatment Process
Knoxville's surface water supply requires heavy chlorination to stay safe — but that creates a tradeoff. The treatment process generates disinfection byproducts: TTHMs at 40.8 ppb (51% of the legal limit, but 272x the EWG guideline) and HAA5 at 30.1 ppb (50% of the legal limit, but 301x the EWG guideline). These are within legal limits, but the EWG sets much tighter thresholds based on cancer-risk research. A whole-house activated carbon filter reduces both chlorine and byproducts.
Chromium-6 was detected at 0.0505 ppb, which is 2.5x the EWG health guideline. There's no separate federal limit for chromium-6, only total chromium. A reverse osmosis system is the most effective removal method. All measurements are within federal legal limits. The EWG guidelines represent a more conservative, health-based standard.
| Contaminant | Detected | Health Guideline | Legal Limit | Status |
|---|---|---|---|---|
| Hardness (as CaCO₃) | 90 PPM | < 60 PPM | No federal limit | ✓ OK |
| Total Dissolved Solids | 130 PPM | < 300 PPM | 500 PPM | ✓ OK |
| PFAS (total) | 3.7 ppt | — | No total limit | Detected |
| ↳ PFOA | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| ↳ PFOS | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| Lead | 0.6 ppb | 0 ppb (no safe level) | 15 ppb (10 ppb in 2027) | ✓ Low |
| Chlorine / Chloramine | 1 mg/L | Taste threshold ~1.0 | 4.0 mg/L | ✓ Normal |
| Nitrate | 0.473 mg/L | 5 mg/L | 10 mg/L | ✓ OK |
Recommendations for Knoxville Homes
Quick Fix for Chlorine: Shower Filter
At 1 mg/L chlorine, many Knoxville residents notice dry skin, brittle hair, and that "pool smell" in the shower. A shower filter installs in 5 minutes, no tools needed.
How to Test Your Water in Knoxville
City-wide data is a solid starting point, but your specific tap might differ based on plumbing age, distance from the treatment plant, or seasonal changes.
Free option: Request KUB's annual Consumer Confidence Report for official city-level data.
📊 Already Tested Your Water?
City averages miss neighborhood-level variation. Share your results to help your neighbors get better data.
We review every submission before publishing. Your ZIP is shown; your identity is not.
About Knoxville's Water Supply
Water Utility: KUB
Water Source: Tennessee River + Fort Loudoun Lake (Surface Water)
Population Served: 254,671
Hardness: 90 PPM (5.3 grains per gallon)
Knoxville's drinking water comes from surface sources — Tennessee River + Fort Loudoun Lake. Surface water requires more extensive treatment than groundwater, including coagulation, filtration, and disinfection. This heavier chlorination is why disinfection byproducts tend to be higher in surface-supplied systems. On the upside, surface sources often deliver softer water than deep aquifers. The system serves 255,000 residents.
Water quality can vary by neighborhood and season. For your exact numbers, request KUB's Consumer Confidence Report (CCR) or test your own tap.
ZIP Codes Covered by This Report
This water quality data applies to all areas served by KUB in Knoxville, TN, including ZIP codes:
24248, 24281, 37705, 37707, 37708, 37709, 37713, 37714, 37715, 37721, 37722, 37724, 37725, 37729, 37730, 37738, 37752, 37754, 37755, 37756, 37757, 37760, 37762, 37764, 37766, 37769, 37773, 37778, 37779, 37806, 37807, 37811, 37813, 37814, 37815, 37816, 37819, 37820, 37821, 37822, 37824, 37825, 37828, 37841, 37847, 37848, 37851, 37860, 37861, 37862, 37863, 37864, 37865, 37866, 37867, 37868, 37869, 37870, 37871, 37876, 37877, 37879, 37881, 37888, 37890, 37901, 37902, 37909, 37912, 37914, 37915, 37916, 37917, 37918, 37919, 37920, 37921, 37922, 37923, 37924, 37927, 37928, 37929, 37930, 37931, 37932, 37933, 37934, 37938, 37939, 37940, 37950, 37995, 37996, 37997, 37998, 40965
If your ZIP code is listed above, this report covers your water supply. Water quality may vary slightly by neighborhood.
Compare Knoxville to Other Tennessee Cities
Nashville
Memphis
Chattanooga
Knoxville West
Clarksville
Hendersonville
Chattanooga Downtown
Murfreesboro
Frequently Asked Questions About Knoxville Water
Is Knoxville tap water safe to drink?
Where does Knoxville's water come from?
Do I need a water softener in Knoxville?
What is the hardness of Knoxville water in grains per gallon?
What are disinfection byproducts in Knoxville's water?
Is chromium-6 in Knoxville's water?
Why does Knoxville water taste like chlorine?
Can I drink Knoxville tap water straight from the faucet?
Data sources: Lead and copper data from EPA Safe Drinking Water Act LCR reporting. Contaminant data from utility-reported testing results. PFAS data from EPA UCMR5 (2023–2025). Hardness from USGS and municipal reports. Data reflects system-level testing results and may not match your specific tap due to neighborhood plumbing, season, or recent utility changes. For your utility's latest results, request their Consumer Confidence Report (CCR). Our methodology. Last updated: 2026-02-24.
What Knoxville Homeowners Actually Buy
Common purchases for homes with 90 PPM water.
Affiliate disclosure: we may earn a commission. Selection based on Knoxville's water data.