Fluoride
Janesville Water Utility
Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems. Read More.
Fluoride has been promoted as a chemical that reduces dental cavities. Yet it is now well-established that fluoride primarily exerts its protective effects through topical mechanisms, such as sodium fluoride in toothpaste and mouthwash. In contrast, long-term ingestion of fluoride in water increases dental fluorosis, which includes mottling, pitting and weakening of the teeth. EPA's maximum legal limit is set at 4 parts per million (ppm) to prevent skeletal fluorosis, a condition where bones become brittle and more susceptible to fractures, although these effects may occur at lower doses.
Even fluoride levels of 0.7 ppm, the amount of fluoride in drinking water recommended by the U.S. Public Health Service, can result in too much fluoride for bottle-fed babies. EWG recommends that caregivers mix baby formula with fluoride-free water. The National Toxicology Program is investigating the potential for low doses of fluoride to alter thyroid function and childhood brain development.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | 0.629 ppm | 29 | 29 | 0.0890 ppm - 0.900 ppm |
| 2015 | 0.645 ppm | 24 | 24 | 0.555 ppm - 0.800 ppm |
| 2016 | 0.596 ppm | 24 | 24 | 0.331 ppm - 0.700 ppm |
| 2017 | 0.564 ppm | 27 | 27 | 0.0600 ppm - 0.800 ppm |
| 2018 | 0.570 ppm | 24 | 24 | 0.330 ppm - 0.800 ppm |
| 2019 | 0.566 ppm | 24 | 24 | 0.377 ppm - 0.800 ppm |
ppm = parts per million
State and national drinking water standards and health guidelines
EPA Maximum Contaminant
Level (MCL) 4 ppm
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-01-14 | 116376001 | 0.588 ppm |
| 2014-01-14 | 116376001 | 0.700 ppm |
| 2014-02-19 | 120376001 | 0.477 ppm |
| 2014-02-19 | 120376001 | 0.700 ppm |
| 2014-02-25 | 771930 | 0.390 ppm |
| 2014-02-25 | 771934 | 0.390 ppm |
| 2014-02-25 | 771924 | 0.560 ppm |
| 2014-02-26 | 772238 | 0.0890 ppm |
| 2014-02-26 | 772231 | 0.0930 ppm |
| 2014-03-19 | 124317001 | 0.700 ppm |
| 2014-03-19 | 124317001 | 0.731 ppm |
| 2014-04-16 | 128218001 | 0.811 ppm |
| 2014-04-16 | 128218001 | 0.900 ppm |
| 2014-05-14 | 133063001 | 0.577 ppm |
| 2014-05-14 | 133063001 | 0.700 ppm |
| 2014-06-19 | 140396001 | 0.633 ppm |
| 2014-06-19 | 140396001 | 0.700 ppm |
| 2014-07-21 | 146613001 | 0.639 ppm |
| 2014-07-21 | 146613001 | 0.800 ppm |
| 2014-08-13 | 151407001 | 0.682 ppm |
| 2014-08-13 | 151407001 | 0.700 ppm |
| 2014-09-15 | 157372001 | 0.620 ppm |
| 2014-09-15 | 157372001 | 0.900 ppm |
| 2014-10-13 | 163743001 | 0.660 ppm |
| 2014-10-13 | 163743001 | 0.800 ppm |
| 2014-11-19 | 169551001 | 0.619 ppm |
| 2014-11-19 | 169551001 | 0.700 ppm |
| 2014-12-16 | 173152001 | 0.681 ppm |
| 2014-12-16 | 173152001 | 0.700 ppm |
| 2015-01-15 | 175977001 | 0.607 ppm |
| 2015-01-15 | 175977001 | 0.700 ppm |
| 2015-02-12 | 179625001 | 0.679 ppm |
| 2015-02-12 | 179625001 | 0.800 ppm |
| 2015-03-16 | 183742001 | 0.616 ppm |
| 2015-03-16 | 183742001 | 0.700 ppm |
| 2015-04-16 | 188405001 | 0.624 ppm |
| 2015-04-16 | 188405001 | 0.700 ppm |
| 2015-05-13 | 193598001 | 0.601 ppm |
| 2015-05-13 | 193598001 | 0.800 ppm |
| 2015-06-16 | 200353001 | 0.644 ppm |
| 2015-06-16 | 200353001 | 0.700 ppm |
| 2015-07-14 | 205852001 | 0.583 ppm |
| 2015-07-14 | 205852001 | 0.700 ppm |
| 2015-08-17 | 212273001 | 0.582 ppm |
| 2015-08-17 | 212273001 | 0.600 ppm |
| 2015-09-15 | 217875001 | 0.555 ppm |
| 2015-09-15 | 217875001 | 0.700 ppm |
| 2015-10-14 | 223997001 | 0.578 ppm |
| 2015-10-14 | 223997001 | 0.600 ppm |
| 2015-11-17 | 229342001 | 0.560 ppm |
| 2015-11-17 | 229342001 | 0.600 ppm |
| 2015-12-16 | 233370001 | 0.559 ppm |
| 2015-12-16 | 233370001 | 0.700 ppm |
| 2016-01-18 | 236573001 | 0.565 ppm |
| 2016-01-18 | 236573001 | 0.700 ppm |
| 2016-02-15 | 240133001 | 0.582 ppm |
| 2016-02-15 | 240133001 | 0.700 ppm |
| 2016-03-15 | 244446001 | 0.553 ppm |
| 2016-03-15 | 244446001 | 0.600 ppm |
| 2016-04-13 | 248789001 | 0.542 ppm |
| 2016-04-13 | 248789001 | 0.700 ppm |
| 2016-05-18 | 255642001 | 0.331 ppm |
| 2016-05-18 | 255642001 | 0.600 ppm |
| 2016-06-14 | 260790001 | 0.564 ppm |
| 2016-06-14 | 260790001 | 0.700 ppm |
| 2016-07-18 | 267196001 | 0.485 ppm |
| 2016-07-18 | 267196001 | 0.600 ppm |
| 2016-08-15 | 272284001 | 0.560 ppm |
| 2016-08-15 | 272284001 | 0.600 ppm |
| 2016-09-13 | 277938001 | 0.521 ppm |
| 2016-09-13 | 277938001 | 0.700 ppm |
| 2016-10-17 | 284835001 | 0.538 ppm |
| 2016-10-17 | 284835001 | 0.700 ppm |
| 2016-11-14 | 289415001 | 0.531 ppm |
| 2016-11-14 | 289415001 | 0.700 ppm |
| 2016-12-14 | 293383001 | 0.537 ppm |
| 2016-12-14 | 293383001 | 0.700 ppm |
| 2017-01-16 | 296794001 | 0.481 ppm |
| 2017-01-16 | 296794001 | 0.700 ppm |
| 2017-02-14 | 300262001 | 0.581 ppm |
| 2017-02-14 | 300262001 | 0.700 ppm |
| 2017-03-14 | 304545001 | 0.496 ppm |
| 2017-03-14 | 304545001 | 0.800 ppm |
| 2017-04-11 | 982415 | 0.510 ppm |
| 2017-04-11 | 982423 | 0.520 ppm |
| 2017-04-11 | 982420 | 0.550 ppm |
| 2017-04-12 | 309669001 | 0.561 ppm |
| 2017-04-12 | 309669001 | 0.700 ppm |
| 2017-05-15 | 315975001 | 0.564 ppm |
| 2017-05-15 | 315975001 | 0.700 ppm |
| 2017-06-13 | 322060001 | 0.535 ppm |
| 2017-06-13 | 322060001 | 0.600 ppm |
| 2017-07-19 | 330194001 | 0.0600 ppm |
| 2017-07-19 | 330194001 | 0.428 ppm |
| 2017-08-14 | 335711001 | 0.537 ppm |
| 2017-08-14 | 335711001 | 0.600 ppm |
| 2017-09-12 | 342103001 | 0.510 ppm |
| 2017-09-12 | 342103001 | 0.700 ppm |
| 2017-10-16 | 349780001 | 0.521 ppm |
| 2017-10-16 | 349780001 | 0.600 ppm |
| 2017-11-14 | 354694001 | 0.521 ppm |
| 2017-11-14 | 354694001 | 0.600 ppm |
| 2017-12-13 | 359496001 | 0.550 ppm |
| 2017-12-13 | 359496001 | 0.600 ppm |
| 2018-01-16 | 363090001 | 0.538 ppm |
| 2018-01-16 | 363090001 | 0.600 ppm |
| 2018-02-13 | 367181001 | 0.330 ppm |
| 2018-02-13 | 367181001 | 0.600 ppm |
| 2018-03-13 | 371407001 | 0.506 ppm |
| 2018-03-13 | 371407001 | 0.700 ppm |
| 2018-04-17 | 377154001 | 0.528 ppm |
| 2018-04-17 | 377154001 | 0.600 ppm |
| 2018-05-15 | 382737001 | 0.475 ppm |
| 2018-05-15 | 382737001 | 0.600 ppm |
| 2018-06-12 | 388542001 | 0.507 ppm |
| 2018-06-12 | 388542001 | 0.700 ppm |
| 2018-07-10 | 393620001 | 0.532 ppm |
| 2018-07-10 | 393620001 | 0.700 ppm |
| 2018-08-14 | 401242001 | 0.533 ppm |
| 2018-08-14 | 401242001 | 0.600 ppm |
| 2018-09-11 | 407283001 | 0.434 ppm |
| 2018-09-11 | 407283001 | 0.600 ppm |
| 2018-10-17 | 415218001 | 0.522 ppm |
| 2018-10-17 | 415218001 | 0.700 ppm |
| 2018-11-13 | 420135001 | 0.476 ppm |
| 2018-11-13 | 420135001 | 0.600 ppm |
| 2018-12-11 | 424404001 | 0.490 ppm |
| 2018-12-11 | 424404001 | 0.800 ppm |
| 2019-01-15 | 428248001 | 0.473 ppm |
| 2019-01-15 | 428248001 | 0.600 ppm |
| 2019-02-12 | 431136001 | 0.499 ppm |
| 2019-02-12 | 431136001 | 0.800 ppm |
| 2019-03-12 | 435413001 | 0.566 ppm |
| 2019-03-12 | 435413001 | 0.600 ppm |
| 2019-04-17 | 441334001 | 0.473 ppm |
| 2019-04-17 | 441334001 | 0.600 ppm |
| 2019-05-14 | 446513001 | 0.467 ppm |
| 2019-05-14 | 446513001 | 0.600 ppm |
| 2019-06-19 | 453109002 | 0.377 ppm |
| 2019-06-19 | 453109002 | 0.600 ppm |
| 2019-07-10 | 457226001 | 0.520 ppm |
| 2019-07-10 | 457226001 | 0.700 ppm |
| 2019-08-13 | 463621001 | 0.535 ppm |
| 2019-08-13 | 463621001 | 0.600 ppm |
| 2019-09-17 | 471365001 | 0.424 ppm |
| 2019-09-17 | 471365001 | 0.700 ppm |
| 2019-10-15 | 476629001 | 0.519 ppm |
| 2019-10-15 | 476629001 | 0.700 ppm |
| 2019-11-12 | 481542001 | 0.516 ppm |
| 2019-11-12 | 481542001 | 0.600 ppm |
| 2019-12-17 | 486837001 | 0.526 ppm |
| 2019-12-17 | 486837001 | 0.600 ppm |