Know what’s in your water before anyone recommends equipment.
Most Knoxville homes drink KUB water drawn from the Tennessee River. In 2025 it measured 94 ppm of hardness, which is moderately hard, and like all city water it reaches your tap with chlorine in it[1]. Homes on Hallsdale-Powell, Knox-Chapman or another district get different water, so a free in-home test is the quickest way to know your own numbers.
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Knoxville is a city-water town. By USGS estimates, only about 1% of Knox County residents (3,678 of 451,324 in 2015) supplied their own water from a well[2]. So the first question is which utility is on your bill.
| KUB hardness | 94 ppm, about 5.5 grains per gallon[1]. USGS calls 61–120 mg/L moderately hard[5]. |
|---|---|
| KUB chlorine at the tap | Highest running annual average 1.6 ppm; samples ranged 0.5–2.4 ppm (2025)[1]. |
| KUB disinfection byproducts | Total trihalomethanes: highest locational running average 56 ppb, single sites 20–79 ppb (federal limit 80)[1]. |
| KUB lead | 90th percentile 0.6 ppb, against the 15 ppb action level[1]. |
| KUB PFAS (EPA UCMR 5) | PFBS detected at 3.7 ppt in one sample (April 17, 2024). No PFOA or PFOS at or above EPA’s 4 ppt reporting level[6]. |
| Hallsdale-Powell chlorine | Averages 1.52 ppm (Melton Hill plant) and 1.68 ppm (Norris plant) in 2025[3]. |
| Hallsdale-Powell PFAS (UCMR 5) | No PFAS at or above EPA reporting levels in 2025 samples[6]. |
| Knox-Chapman hardness | 57 ppm average, range 40–74 ppm (2025)[4]. |
| Homes on private wells | About 1% of Knox County residents (USGS, 2015)[2]. |
Numbers come from each utility’s own report and EPA/USGS data, checked November 2026. Water changes from street to street, so book a free test for your home.
You’ll find websites that put Knoxville at 8 grains per gallon or more. KUB’s own lab measured 94 ppm in 2025, which works out to about 5.5 grains[1]. That’s moderately hard: enough to leave white spots on glasses, scale in a water heater and a ring in the tub, but not the very hard water some well owners deal with. Knox-Chapman reported 57 ppm, close to the soft line[4]. Hallsdale-Powell, First Utility District and West Knox don’t publish a hardness number, so we measure it at your sink.
Whether a water softener makes sense on 5.5 grains depends on what bothers you. Many KUB homes notice spots and scale and want them gone. Others care more about taste and chlorine. We’ll show you the numbers and let you decide.
KUB disinfects with chlorine and chlorine dioxide, the way federal rules require, and the chlorine is still in the water at your tap: 0.5 to 2.4 ppm across KUB’s 2025 samples[1]. When chlorine meets natural organic matter in river water, it forms byproducts called trihalomethanes. KUB’s highest running average was 56 ppb, with single samples up to 79 ppb[1]. Meeting the federal limit is the legal test. It doesn’t mean you want those chemicals in your shower or your coffee. Whole-house filtration takes chlorine back out where water enters the house.
If your bill says Hallsdale-Powell, your water comes from Melton Hill Lake or Norris Lake rather than the Tennessee River. The district filters both through membranes and reported chlorine averages of 1.52 and 1.68 ppm in 2025[3]. Its highest trihalomethane running average was 44.9 ppb[3]. The district’s 2025 UCMR 5 samples showed no PFAS at or above EPA’s reporting levels[6].
Your utility treats and tests the water before it leaves the plant. What it can’t control is the chlorine still in the water, the hardness that stays in, and anything your home’s own plumbing adds. Most KUB homes we test need filtration for chlorine, often a softener, and reverse osmosis for drinking water.
The few Knox County homes on wells test them on their own schedule. EPA advises testing a private well every year for total coliform bacteria, nitrates, total dissolved solids and pH[7]. A well usually needs a different setup: sediment and iron handling, softening and UV light for bacteria. See well water treatment.
We wrote a separate guide that walks through KUB’s 2025 report line by line, including hardness, lead and PFAS: Knoxville’s water quality report, explained.
KUB reports that its drinking water met all existing standards in 2025, and its lead results were low, with a 90th percentile of 0.6 ppb against the 15 ppb action level. Meeting standards is the legal answer. Your glass also carries the chlorine added for disinfection, natural hardness and whatever your own plumbing adds. A free in-home test shows what comes out of your tap.
Yes, moderately. KUB measured 94 ppm of hardness in 2025, about 5.5 grains per gallon, which the USGS scale calls moderately hard. That’s lower than many websites claim. Knox-Chapman reported 57 ppm. Hallsdale-Powell, First Utility District and West Knox don’t publish a figure, so the simplest way to know your number is a free test at your sink.
In EPA’s UCMR 5 testing, KUB had one PFAS compound, PFBS, detected at 3.7 ppt in one April 2024 sample. PFBS isn’t one of the two compounds with EPA’s 4 ppt limit, and no PFOA or PFOS was found at or above EPA’s reporting level. Hallsdale-Powell’s 2025 samples showed no PFAS at or above EPA reporting levels.
You don’t need one to meet federal standards, but many Knoxville families want one. KUB water reaches your tap with chlorine in it, measures about 5.5 grains of hardness and carries disinfection byproducts at low levels. Whole-house filtration handles chlorine, a softener handles hardness, and reverse osmosis covers drinking water. A free test shows which of those your home actually needs.
Perfected Water. Purified Air. Peace of Mind. It starts with a free in-home test.
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