Fluoride in Louisville, TN Water: 0.31 mg/L — the Natural Range
Louisville's utility district voted to fluoridate back in 2008, but its recent reports measure only about 0.31 mg/L — the range of naturally occurring fluoride, well below the CDC's 0.7 mg/L target. Here's the number, the trend across the district's recent reports, and what it means for toothpaste, kids, and anyone on a well.
Louisville's tap water measures about 0.31 mg/L of fluoride — the range of naturally occurring fluoride, and less than half the CDC's recommended 0.7 mg/L. South Blount County Utility District (TN0000643) voted in 2008 to start fluoridating, but its most recent Consumer Confidence Report (the 2026 report, covering 2025 data) reports just 0.3143 mg/L (range 0.182–0.387 mg/L), and nothing in its current reports shows the level adjusted up to the 0.7 mg/L target.
Water quality in Louisville
Curious about your tap water? Tennessee Water Authority has the full Louisville water quality guide — contaminant data, utility details, and filter recommendations.
How to read this page: every Louisville figure comes from South Blount County Utility District's own Consumer Confidence Reports (CCRs) — the most recent is the 2026 report (2025 data), published on the district's own website — not from estimates or national averages. For drinking water, mg/L and ppm are the same thing, and this page uses mg/L throughout. This page covers Louisville homes served by South Blount County Utility District. If another utility's name is on your water bill, or you're on a private well, your fluoridation status may be different — see the well note below.
The full picture: our complete fluoride guide
This page is the Louisville companion — the local number and what it means. For the statewide walkthrough (how fluoridation works, the safety evidence, filters that remove fluoride, and how Tennessee cities compare), see our complete fluoride guide.
Louisville's fluoride level, against the benchmarks
South Blount County Utility District's most recent Consumer Confidence Report — the report for 2026, covering 2025 data — reports fluoride at 0.3143 mg/L, with samples ranging from 0.182 to 0.387 mg/L. That is the range of naturally occurring fluoride, and it is less than half the CDC's recommended 0.7 mg/L. The district's recent reports show the level drifting down over time: 0.47 → 0.37 → 0.3098 → 0.3143 mg/L. Nothing in the current reports shows fluoride being adjusted up to the 0.7 mg/L target — and Louisville remains far below both EPA standards.
- Utility
- South Blount County Utility DistrictLouisville's primary water utility · Tellico Lake surface water, Blount County
- Public water system ID
- TN0000643
- Fluoridation status
- Measured at natural levels — not adjusted to the CDC targetBoard voted to start fluoridating in 2008; recent CCRs measure only ~0.31 mg/L, the natural range
- Fluoride level (2025)
- 0.31 mg/LReported as 0.3143 mg/L · range 0.182–0.387 mg/L · 2026 Consumer Confidence Report (2025 data). Recent CCR trend: 0.47 → 0.37 → 0.3098 → 0.3143 mg/L
| Measure | Level | What it is |
|---|---|---|
| South Blount County UD — measured level, 2025 | 0.31 mg/LReported 0.3143 mg/L · range 0.182–0.387 mg/L | From the utility's own 2026 Consumer Confidence Report (2025 data). Recent CCRs trend 0.47 → 0.37 → 0.3098 → 0.3143 mg/L — the range of naturally occurring fluoride |
| CDC recommended level | 0.7 mg/L | The level U.S. public health agencies recommend for balancing cavity protection against fluorosis risk. Louisville's measured level is less than half of this |
| EPA enforceable maximum contaminant level (MCL) | 4.0 mg/L | The enforceable legal ceiling for fluoride in public drinking water. Louisville's result is a small fraction of it — no violation |
| EPA secondary (non-enforceable) standard | 2.0 mg/L | A non-enforceable guideline aimed at preventing cosmetic dental fluorosis (mottling) in children. Louisville is far below it |
Don't confuse the three federal numbers — they're often scrambled in online discussions. 0.7 mg/L is the CDC's recommendation (the target for cavity prevention). 2.0 mg/L is the EPA's secondary standard (a guideline about cosmetic effects). 4.0 mg/L is the EPA's enforceable maximum. Louisville's 0.31 mg/L lands below the first and far below the other two.
The 2008 vote — and what the water measures today
South Blount County Utility District's fluoridation story starts in January 2008, when its board voted to begin fluoridating; fluoridation started in May 2008. The decision drew a lawsuit, which was dismissed, and a poll around 2012 supported continuing. So the district's intent to fluoridate is a matter of record. What its recent water-quality reports actually measure, though, is fluoride at only about 0.31 mg/L — the range of naturally occurring fluoride — with nothing in the current Consumer Confidence Reports showing the level adjusted up to the CDC's 0.7 mg/L target. If you need to know whether the district is actively adding fluoride today, the district itself is the source to ask.
What 0.31 mg/L means for your teeth
At about 0.31 mg/L, Louisville's water carries less than half the fluoride of an adjusted supply — enough to contribute some background protection as you drink it, but not the full benefit fluoridation at the CDC level is supposed to deliver. That makes the things you control — toothpaste first of all, and in-office fluoride for higher-risk teeth — carry more weight here than they would in a town held at 0.7 mg/L.
01 Do you still need fluoride toothpaste?
Yes. Water is background exposure; toothpaste is the main event. Brushing puts a concentrated dose of fluoride directly on the enamel surface, twice a day — that's where most cavity protection actually comes from, in Louisville and everywhere else.
That matters even more in Louisville, where the tap water's natural-range fluoride (~0.31 mg/L) provides only modest background help. Keep brushing twice daily with fluoride toothpaste. Skipping it because "the water has fluoride" gives up the strongest protection you have.
02 Kids: small amounts, supervised
Children need fluoride toothpaste too — in the right amount. The ADA's guidance: a rice-grain smear for children under age 3, and a pea-size amount from age 3 up.
Supervise brushing and teach kids to spit, not swallow. Young children who swallow toothpaste day after day can take in more fluoride than they need while their permanent teeth are still forming — the amounts above are sized to prevent exactly that while still protecting the teeth.
03 Fluoride varnish: matters more on a natural-range supply
Louisville's water is not an adjusted supply — it measures only ~0.31 mg/L, less than half the CDC target — so the background protection from your tap is modest, and in-office treatments carry more of the load than they would in a town held at 0.7 mg/L.
In-office fluoride varnish is worthwhile for kids and adults at higher cavity risk — children who keep getting cavities, anyone with dry mouth, or teeth with a history of decay — because it delivers a much stronger, longer-lasting dose than natural-range water ever will. Given the low water level, it's also a reasonable conversation for lower-risk kids. Your dentist can tell you which side of that line you're on.
04 On a private well? Different rules
Private wells are not fluoridated by any utility — whatever fluoride is in well water is whatever occurs naturally in the ground, which varies and is usually low.
If your home is on a well, get the water tested before even thinking about fluoride supplements. Supplements dosed without knowing the water's natural level can overshoot, and they should only ever be used with a dentist's or pediatrician's input — never as a guess.
How to confirm it yourself
Don't take our word for it — the primary document is public, and checking it takes two minutes.
- Read South Blount's Consumer Confidence Report. The district's report for 2026 (2025 data), posted on its own website at southblountutility.org, lists fluoride at 0.3143 mg/L, range 0.182–0.387 mg/L. A new report is published each year — next year's is the one to watch for changes.
- Check CDC My Water's Fluoride. The CDC's My Water's Fluoride database tracks fluoridation status by water system and county — a good cross-check on the district's status.
- On a different utility? Find that utility's own Consumer Confidence Report (utilities must make it available to customers annually) and look for the fluoride row: the level detected, the range, and whether the utility describes adjusting or adding fluoride.
- On a private well? No report exists — your water is yours to test. A certified lab test for fluoride tells you the natural level before you and your dentist or pediatrician discuss whether anything more is needed.
Questions people actually ask us
The real questions from the chair — answered straight, with Louisville's actual numbers.
It is more complicated than a simple yes. South Blount County Utility District's (TN0000643) board voted in January 2008 to start fluoridating, and fluoridation began in May 2008. But the district's recent Consumer Confidence Reports measure fluoride at only about 0.31 mg/L — the range of naturally occurring fluoride — and nothing in its current reports shows the level being adjusted up to the CDC's 0.7 mg/L target. If you need certainty about whether the district is actively adding fluoride today, ask the district directly.
South Blount County Utility District's Consumer Confidence Report for 2026 (2025 data) reports fluoride at 0.3143 mg/L, with samples ranging from 0.182 to 0.387 mg/L. Across its recent reports the level has trended downward: 0.47, then 0.37, then 0.3098, then 0.3143 mg/L. That is well below the CDC recommended level of 0.7 mg/L, and far below the EPA secondary (non-enforceable) standard of 2.0 mg/L and the EPA enforceable maximum contaminant level (MCL) of 4.0 mg/L.
The district's board voted in January 2008 to start fluoridating, and fluoridation began in May 2008. A lawsuit challenging the decision was dismissed, and a poll around 2012 supported continuing. But whatever the district's practice since, its recent Consumer Confidence Reports measure fluoride only at about 0.31 mg/L — the range of naturally occurring fluoride — rather than at the CDC's 0.7 mg/L target.
Yes — and it matters even more here, because Louisville's water carries only natural-range fluoride (about 0.31 mg/L), well below the CDC target. Think of the water as modest background exposure and toothpaste as the main event — toothpaste puts a concentrated dose of fluoride directly on the enamel, twice a day, which is where most of the cavity protection comes from. Brush twice daily with fluoride toothpaste. For children, use a rice-grain smear for under age 3 and a pea-size amount from age 3, supervise brushing, and teach kids to spit rather than swallow.
More likely than in a town whose water is adjusted to the CDC level. Louisville's water measures only about 0.31 mg/L — natural-range fluoride, less than half the CDC's 0.7 mg/L target — so the background protection from tap water here is modest, and in-office fluoride varnish carries more of the load. It is worthwhile for kids — and adults — at higher cavity risk: children who keep getting cavities, anyone with dry mouth, or teeth with a history of decay — and worth discussing even for lower-risk children given the low water level. Ask your dentist where your child falls.
Well water is not fluoridated by any utility — whatever fluoride is in it is whatever occurs naturally in the ground, which varies from place to place and is usually low. Don't assume your well matches South Blount's 0.31 mg/L. Get the water tested first, and only consider fluoride supplements with a dentist's or pediatrician's input — never as a guess.
Read South Blount County Utility District's current Consumer Confidence Report — the report for 2026 (covering 2025 data) is posted on the district's own website, southblountutility.org, and lists fluoride at 0.3143 mg/L (range 0.182–0.387 mg/L). You can also cross-check the district's fluoridation status in the CDC's My Water's Fluoride database. A fresh CCR comes out every year, so next year's report is the one to watch for changes.
Sources
- South Blount County Utility District — Consumer Confidence Report for 2026 (2025 data), published on the district's own website, southblountutility.org: fluoride 0.3143 mg/L, range 0.182–0.387 mg/L; district treats Tellico Lake surface water, PWSID TN0000643. Earlier CCRs report 0.47, 0.37, and 0.3098 mg/L — the trend behind this page's figures (accessed October 20, 2026). Primary source for Louisville's level.
- District history: South Blount County Utility District's board voted in January 2008 to begin fluoridating; fluoridation began in May 2008; a lawsuit over the decision was dismissed; a poll around 2012 supported continuing. The district's recent CCRs nonetheless measure fluoride only in the natural range (~0.31 mg/L), with no adjustment to the 0.7 mg/L target shown.
- CDC — community water fluoridation: recommended fluoride level for drinking water, 0.7 mg/L. Cross-check any system's status in CDC My Water's Fluoride.
- U.S. EPA — National Primary and Secondary Drinking Water Regulations: fluoride enforceable maximum contaminant level (MCL) 4.0 mg/L; secondary standard 2.0 mg/L.
- American Dental Association: fluoride toothpaste amounts for children — rice-grain smear under age 3, pea-size amount from age 3.