Fluoride
Port Washington Waterworks
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 | 0.666 ppm | 25 | 25 | 0.543 ppm - 0.790 ppm |
| 2015 | 0.621 ppm | 25 | 25 | 0.439 ppm - 0.760 ppm |
| 2016 | 0.602 ppm | 25 | 25 | 0.454 ppm - 0.830 ppm |
| 2017 | 0.654 ppm | 25 | 25 | 0.510 ppm - 0.890 ppm |
| 2018 | 0.662 ppm | 25 | 25 | 0.575 ppm - 0.840 ppm |
| 2019 | 0.663 ppm | 25 | 25 | 0.585 ppm - 0.790 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 |
|---|---|---|
| 2014-01-08 | 115485001 | 0.676 ppm |
| 2014-01-08 | 115485001 | 0.760 ppm |
| 2014-02-04 | 118572001 | 0.586 ppm |
| 2014-02-04 | 118572001 | 0.780 ppm |
| 2014-03-10 | 122996001 | 0.623 ppm |
| 2014-03-10 | 122996001 | 0.790 ppm |
| 2014-04-03 | 126093001 | 0.640 ppm |
| 2014-04-03 | 126093001 | 0.710 ppm |
| 2014-04-08 | 3004182-83 | 0.700 ppm |
| 2014-05-07 | 131218001 | 0.543 ppm |
| 2014-05-07 | 131218001 | 0.600 ppm |
| 2014-06-03 | 136573001 | 0.635 ppm |
| 2014-06-03 | 136573001 | 0.740 ppm |
| 2014-07-08 | 144115001 | 0.561 ppm |
| 2014-07-08 | 144115001 | 0.730 ppm |
| 2014-08-12 | 150946001 | 0.553 ppm |
| 2014-08-12 | 150946001 | 0.650 ppm |
| 2014-09-03 | 154877001 | 0.611 ppm |
| 2014-09-03 | 154877001 | 0.720 ppm |
| 2014-10-07 | 162234001 | 0.697 ppm |
| 2014-10-07 | 162234001 | 0.720 ppm |
| 2014-11-04 | 167033001 | 0.678 ppm |
| 2014-11-04 | 167033001 | 0.720 ppm |
| 2014-12-02 | 170970001 | 0.588 ppm |
| 2014-12-02 | 170970001 | 0.630 ppm |
| 2015-01-05 | 174455001 | 0.630 ppm |
| 2015-01-05 | 174455001 | 0.720 ppm |
| 2015-02-04 | 178581001 | 0.639 ppm |
| 2015-02-04 | 178581001 | 0.760 ppm |
| 2015-03-05 | 182302001 | 0.439 ppm |
| 2015-03-05 | 182302001 | 0.550 ppm |
| 2015-04-06 | 186511001 | 0.534 ppm |
| 2015-04-06 | 186511001 | 0.650 ppm |
| 2015-04-07 | 3219659-60 | 0.600 ppm |
| 2015-05-04 | 191021001 | 0.600 ppm |
| 2015-05-04 | 191021001 | 0.660 ppm |
| 2015-06-08 | 198117001 | 0.605 ppm |
| 2015-06-08 | 198117001 | 0.690 ppm |
| 2015-07-06 | 204281001 | 0.571 ppm |
| 2015-07-06 | 204281001 | 0.640 ppm |
| 2015-08-03 | 209482001 | 0.564 ppm |
| 2015-08-03 | 209482001 | 0.690 ppm |
| 2015-09-01 | 214941001 | 0.604 ppm |
| 2015-09-01 | 214941001 | 0.630 ppm |
| 2015-10-07 | 222643001 | 0.621 ppm |
| 2015-10-07 | 222643001 | 0.690 ppm |
| 2015-11-09 | 228050001 | 0.601 ppm |
| 2015-11-09 | 228050001 | 0.620 ppm |
| 2015-12-01 | 230804001 | 0.599 ppm |
| 2015-12-01 | 230804001 | 0.630 ppm |
| 2016-01-07 | 235062001 | 0.621 ppm |
| 2016-01-07 | 235062001 | 0.690 ppm |
| 2016-02-03 | 238277001 | 0.558 ppm |
| 2016-02-03 | 238277001 | 0.660 ppm |
| 2016-03-04 | 242278001 | 0.552 ppm |
| 2016-03-04 | 242278001 | 0.600 ppm |
| 2016-04-04 | 247280001 | 0.682 ppm |
| 2016-04-04 | 247280001 | 0.830 ppm |
| 2016-05-02 | 251983001 | 0.524 ppm |
| 2016-05-02 | 251983001 | 0.580 ppm |
| 2016-05-05 | 3443037-38 | 0.500 ppm |
| 2016-06-01 | 257686001 | 0.553 ppm |
| 2016-06-01 | 257686001 | 0.620 ppm |
| 2016-07-11 | 265229001 | 0.515 ppm |
| 2016-07-11 | 265229001 | 0.630 ppm |
| 2016-08-02 | 269818001 | 0.454 ppm |
| 2016-08-02 | 269818001 | 0.550 ppm |
| 2016-09-12 | 277120001 | 0.551 ppm |
| 2016-09-12 | 277120001 | 0.620 ppm |
| 2016-10-05 | 282532001 | 0.570 ppm |
| 2016-10-05 | 282532001 | 0.600 ppm |
| 2016-11-02 | 287252001 | 0.584 ppm |
| 2016-11-02 | 287252001 | 0.690 ppm |
| 2016-12-06 | 292140001 | 0.634 ppm |
| 2016-12-06 | 292140001 | 0.680 ppm |
| 2017-01-03 | 294902001 | 0.539 ppm |
| 2017-01-03 | 294902001 | 0.610 ppm |
| 2017-02-02 | 298335001 | 0.600 ppm |
| 2017-02-02 | 298335001 | 0.680 ppm |
| 2017-03-07 | 303170001 | 0.595 ppm |
| 2017-03-07 | 303170001 | 0.670 ppm |
| 2017-04-03 | 307574001 | 0.623 ppm |
| 2017-04-03 | 307574001 | 0.730 ppm |
| 2017-04-19 | 3677792-93 | 0.610 ppm |
| 2017-05-01 | 313103001 | 0.640 ppm |
| 2017-05-01 | 313103001 | 0.750 ppm |
| 2017-06-01 | 319069001 | 0.601 ppm |
| 2017-06-01 | 319069001 | 0.700 ppm |
| 2017-07-10 | 327309001 | 0.510 ppm |
| 2017-07-10 | 327309001 | 0.590 ppm |
| 2017-08-03 | 333401001 | 0.601 ppm |
| 2017-08-03 | 333401001 | 0.700 ppm |
| 2017-09-05 | 340495001 | 0.646 ppm |
| 2017-09-05 | 340495001 | 0.670 ppm |
| 2017-10-03 | 346502001 | 0.650 ppm |
| 2017-10-03 | 346502001 | 0.655 ppm |
| 2017-11-07 | 353521001 | 0.697 ppm |
| 2017-11-07 | 353521001 | 0.890 ppm |
| 2017-12-05 | 357935001 | 0.623 ppm |
| 2017-12-05 | 357935001 | 0.760 ppm |
| 2018-01-04 | 361381001 | 0.601 ppm |
| 2018-01-04 | 361381001 | 0.700 ppm |
| 2018-02-06 | 366093001 | 0.652 ppm |
| 2018-02-06 | 366093001 | 0.840 ppm |
| 2018-03-02 | 369117001 | 0.604 ppm |
| 2018-03-02 | 369117001 | 0.740 ppm |
| 2018-04-02 | 374227001 | 0.620 ppm |
| 2018-04-02 | 374227001 | 0.760 ppm |
| 2018-04-03 | 3902865-66 | 0.600 ppm |
| 2018-05-03 | 379833001 | 0.619 ppm |
| 2018-05-03 | 379833001 | 0.750 ppm |
| 2018-06-05 | 386664001 | 0.604 ppm |
| 2018-06-05 | 386664001 | 0.690 ppm |
| 2018-07-10 | 393611001 | 0.632 ppm |
| 2018-07-10 | 393611001 | 0.730 ppm |
| 2018-08-08 | 399894001 | 0.613 ppm |
| 2018-08-08 | 399894001 | 0.740 ppm |
| 2018-09-06 | 405696001 | 0.584 ppm |
| 2018-09-06 | 405696001 | 0.650 ppm |
| 2018-10-02 | 412261001 | 0.602 ppm |
| 2018-10-02 | 412261001 | 0.680 ppm |
| 2018-11-05 | 418123001 | 0.603 ppm |
| 2018-11-05 | 418123001 | 0.730 ppm |
| 2018-12-04 | 422856001 | 0.575 ppm |
| 2018-12-04 | 422856001 | 0.630 ppm |
| 2019-01-07 | 426639001 | 0.591 ppm |
| 2019-01-07 | 426639001 | 0.710 ppm |
| 2019-02-11 | 431044001 | 0.600 ppm |
| 2019-02-11 | 431044001 | 0.720 ppm |
| 2019-03-05 | 434056001 | 0.585 ppm |
| 2019-03-05 | 434056001 | 0.790 ppm |
| 2019-03-11 | 4222486-87 | 0.590 ppm |
| 2019-04-02 | 438696001 | 0.588 ppm |
| 2019-04-02 | 438696001 | 0.750 ppm |
| 2019-05-08 | 445213001 | 0.670 ppm |
| 2019-05-08 | 445213001 | 0.730 ppm |
| 2019-06-13 | 451784001 | 0.606 ppm |
| 2019-06-13 | 451784001 | 0.670 ppm |
| 2019-07-09 | 457033001 | 0.640 ppm |
| 2019-07-09 | 457033001 | 0.740 ppm |
| 2019-08-05 | 462449001 | 0.602 ppm |
| 2019-08-05 | 462449001 | 0.730 ppm |
| 2019-09-03 | 467520001 | 0.597 ppm |
| 2019-09-03 | 467520001 | 0.720 ppm |
| 2019-10-01 | 473959001 | 0.617 ppm |
| 2019-10-01 | 473959001 | 0.640 ppm |
| 2019-11-04 | 479595001 | 0.658 ppm |
| 2019-11-04 | 479595001 | 0.710 ppm |
| 2019-12-02 | 484335001 | 0.595 ppm |
| 2019-12-02 | 484335001 | 0.730 ppm |