Fluoride
Rib Mountain Sanitary District
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 |
|---|---|---|---|---|
| 2014 | 0.536 ppm | 28 | 28 | 0.0850 ppm - 0.800 ppm |
| 2015 | 0.592 ppm | 24 | 24 | 0.450 ppm - 0.800 ppm |
| 2016 | 0.541 ppm | 24 | 24 | 0.336 ppm - 0.800 ppm |
| 2017 | 0.472 ppm | 28 | 28 | 0.210 ppm - 0.650 ppm |
| 2018 | 0.540 ppm | 24 | 24 | 0.366 ppm - 0.860 ppm |
| 2019 | 0.479 ppm | 24 | 24 | 0.300 ppm - 0.700 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 |
|---|---|---|
| 2014-01-16 | 116692001 | 0.500 ppm |
| 2014-01-16 | 116692001 | 0.643 ppm |
| 2014-02-18 | 120380001 | 0.679 ppm |
| 2014-02-18 | 120380001 | 0.750 ppm |
| 2014-03-18 | 124174001 | 0.494 ppm |
| 2014-03-18 | 124174001 | 0.520 ppm |
| 2014-04-16 | 128219001 | 0.588 ppm |
| 2014-04-16 | 128219001 | 0.750 ppm |
| 2014-04-30 | 783259 | 0.0850 ppm |
| 2014-04-30 | 783253 | 0.160 ppm |
| 2014-04-30 | 783256 | 0.210 ppm |
| 2014-04-30 | 783250 | 0.340 ppm |
| 2014-05-19 | 133704001 | 0.548 ppm |
| 2014-05-19 | 133704001 | 0.600 ppm |
| 2014-06-17 | 139837001 | 0.483 ppm |
| 2014-06-17 | 139837001 | 0.570 ppm |
| 2014-07-21 | 146615001 | 0.491 ppm |
| 2014-07-21 | 146615001 | 0.560 ppm |
| 2014-08-19 | 152498001 | 0.572 ppm |
| 2014-08-19 | 152498001 | 0.740 ppm |
| 2014-09-22 | 159241001 | 0.500 ppm |
| 2014-09-22 | 159241001 | 0.500 ppm |
| 2014-10-28 | 165854001 | 0.438 ppm |
| 2014-10-28 | 165854001 | 0.730 ppm |
| 2014-11-19 | 169553001 | 0.450 ppm |
| 2014-11-19 | 169553001 | 0.560 ppm |
| 2014-12-10 | 172326001 | 0.756 ppm |
| 2014-12-10 | 172326001 | 0.800 ppm |
| 2015-01-08 | 174974001 | 0.537 ppm |
| 2015-01-08 | 174974001 | 0.800 ppm |
| 2015-02-18 | 180318001 | 0.610 ppm |
| 2015-02-18 | 180318001 | 0.670 ppm |
| 2015-03-24 | 184829001 | 0.576 ppm |
| 2015-03-24 | 184829001 | 0.580 ppm |
| 2015-04-29 | 190565001 | 0.584 ppm |
| 2015-04-29 | 190565001 | 0.720 ppm |
| 2015-05-19 | 194803001 | 0.700 ppm |
| 2015-05-19 | 194803001 | 0.740 ppm |
| 2015-06-23 | 201512001 | 0.461 ppm |
| 2015-06-23 | 201512001 | 0.590 ppm |
| 2015-07-23 | 207725001 | 0.450 ppm |
| 2015-07-23 | 207725001 | 0.500 ppm |
| 2015-08-19 | 213034001 | 0.520 ppm |
| 2015-08-19 | 213034001 | 0.587 ppm |
| 2015-09-17 | 218325001 | 0.478 ppm |
| 2015-09-17 | 218325001 | 0.530 ppm |
| 2015-10-27 | 225759001 | 0.545 ppm |
| 2015-10-27 | 225759001 | 0.670 ppm |
| 2015-11-12 | 228399001 | 0.596 ppm |
| 2015-11-12 | 228399001 | 0.670 ppm |
| 2015-12-08 | 232028001 | 0.520 ppm |
| 2015-12-08 | 232028001 | 0.571 ppm |
| 2016-01-18 | 236022001 | 0.559 ppm |
| 2016-01-18 | 236022001 | 0.730 ppm |
| 2016-02-09 | 239245001 | 0.620 ppm |
| 2016-02-09 | 239245001 | 0.800 ppm |
| 2016-03-11 | 243623001 | 0.554 ppm |
| 2016-03-11 | 243623001 | 0.700 ppm |
| 2016-04-27 | 251117001 | 0.484 ppm |
| 2016-04-27 | 251117001 | 0.560 ppm |
| 2016-05-10 | 253896001 | 0.539 ppm |
| 2016-05-10 | 253896001 | 0.750 ppm |
| 2016-06-14 | 260792001 | 0.460 ppm |
| 2016-06-14 | 260792001 | 0.466 ppm |
| 2016-07-11 | 265224001 | 0.486 ppm |
| 2016-07-11 | 265224001 | 0.540 ppm |
| 2016-08-09 | 271200001 | 0.425 ppm |
| 2016-08-09 | 271200001 | 0.540 ppm |
| 2016-09-23 | 279881001 | 0.417 ppm |
| 2016-09-23 | 279881001 | 0.500 ppm |
| 2016-10-12 | 284040001 | 0.512 ppm |
| 2016-10-12 | 284040001 | 0.700 ppm |
| 2016-11-28 | 290460001 | 0.373 ppm |
| 2016-11-28 | 290460001 | 0.450 ppm |
| 2016-12-09 | 292298001 | 0.336 ppm |
| 2016-12-09 | 292298001 | 0.480 ppm |
| 2017-01-13 | 296206001 | 0.512 ppm |
| 2017-01-13 | 296206001 | 0.600 ppm |
| 2017-02-13 | 299885001 | 0.460 ppm |
| 2017-02-13 | 299885001 | 0.590 ppm |
| 2017-03-21 | 305617001 | 0.507 ppm |
| 2017-03-21 | 305617001 | 0.620 ppm |
| 2017-04-26 | 312220001 | 0.555 ppm |
| 2017-04-26 | 312220001 | 0.630 ppm |
| 2017-05-17 | 990969 | 0.210 ppm |
| 2017-05-17 | 990960 | 0.220 ppm |
| 2017-05-17 | 990963 | 0.260 ppm |
| 2017-05-17 | 990966 | 0.430 ppm |
| 2017-05-25 | 318287001 | 0.300 ppm |
| 2017-05-25 | 318287001 | 0.346 ppm |
| 2017-06-21 | 323773001 | 0.551 ppm |
| 2017-06-21 | 323773001 | 0.650 ppm |
| 2017-07-21 | 330336001 | 0.426 ppm |
| 2017-07-21 | 330336001 | 0.640 ppm |
| 2017-08-29 | 338757001 | 0.400 ppm |
| 2017-08-29 | 338757001 | 0.620 ppm |
| 2017-09-22 | 344319001 | 0.500 ppm |
| 2017-09-22 | 344319001 | 0.526 ppm |
| 2017-10-18 | 349871001 | 0.440 ppm |
| 2017-10-18 | 349871001 | 0.477 ppm |
| 2017-11-27 | 356252001 | 0.488 ppm |
| 2017-11-27 | 356252001 | 0.560 ppm |
| 2017-12-19 | 360250001 | 0.320 ppm |
| 2017-12-19 | 360250001 | 0.381 ppm |
| 2018-01-19 | 363534001 | 0.462 ppm |
| 2018-01-19 | 363534001 | 0.530 ppm |
| 2018-02-21 | 368207001 | 0.570 ppm |
| 2018-02-21 | 368207001 | 0.710 ppm |
| 2018-03-13 | 371191001 | 0.577 ppm |
| 2018-03-13 | 371191001 | 0.580 ppm |
| 2018-04-12 | 376303001 | 0.544 ppm |
| 2018-04-12 | 376303001 | 0.760 ppm |
| 2018-05-29 | 385115001 | 0.418 ppm |
| 2018-05-29 | 385115001 | 0.470 ppm |
| 2018-06-22 | 390435001 | 0.767 ppm |
| 2018-06-22 | 390435001 | 0.860 ppm |
| 2018-07-20 | 395870001 | 0.476 ppm |
| 2018-07-20 | 395870001 | 0.560 ppm |
| 2018-08-21 | 402725001 | 0.366 ppm |
| 2018-08-21 | 402725001 | 0.410 ppm |
| 2018-09-24 | 410109001 | 0.468 ppm |
| 2018-09-24 | 410109001 | 0.600 ppm |
| 2018-10-30 | 417175001 | 0.463 ppm |
| 2018-10-30 | 417175001 | 0.540 ppm |
| 2018-11-19 | 420711001 | 0.438 ppm |
| 2018-11-19 | 420711001 | 0.510 ppm |
| 2018-12-17 | 424911001 | 0.400 ppm |
| 2018-12-17 | 424911001 | 0.472 ppm |
| 2019-01-24 | 429145001 | 0.486 ppm |
| 2019-01-24 | 429145001 | 0.600 ppm |
| 2019-02-19 | 432393001 | 0.448 ppm |
| 2019-02-19 | 432393001 | 0.550 ppm |
| 2019-03-13 | 435427001 | 0.404 ppm |
| 2019-03-13 | 435427001 | 0.480 ppm |
| 2019-04-24 | 442412001 | 0.440 ppm |
| 2019-04-24 | 442412001 | 0.513 ppm |
| 2019-05-28 | 448426001 | 0.505 ppm |
| 2019-05-28 | 448426001 | 0.700 ppm |
| 2019-06-28 | 454663001 | 0.341 ppm |
| 2019-06-28 | 454663001 | 0.480 ppm |
| 2019-07-23 | 459494001 | 0.331 ppm |
| 2019-07-23 | 459494001 | 0.510 ppm |
| 2019-08-27 | 466435001 | 0.300 ppm |
| 2019-08-27 | 466435001 | 0.354 ppm |
| 2019-09-23 | 472127001 | 0.554 ppm |
| 2019-09-23 | 472127001 | 0.600 ppm |
| 2019-10-29 | 478968001 | 0.417 ppm |
| 2019-10-29 | 478968001 | 0.520 ppm |
| 2019-11-19 | 482583001 | 0.428 ppm |
| 2019-11-19 | 482583001 | 0.590 ppm |
| 2019-12-18 | 487143001 | 0.376 ppm |
| 2019-12-18 | 487143001 | 0.570 ppm |