Fluoride
Laurel Water Department
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 | 0.605 ppm | 13 | 13 | 0.150 ppm - 1.35 ppm |
| 2015 | 0.542 ppm | 13 | 13 | 0.270 ppm - 0.780 ppm |
| 2016 | 0.445 ppm | 13 | 13 | 0.150 ppm - 0.790 ppm |
| 2017 | 0.563 ppm | 14 | 14 | 0.110 ppm - 0.990 ppm |
| 2018 | 0.229 ppm | 22 | 20 | ND - 0.929 ppm |
| 2019 | 0.352 ppm | 28 | 28 | 0.141 ppm - 0.586 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 |
|---|---|---|
| 2014-01-23 | S237957 | 0.640 ppm |
| 2014-02-19 | S107839 | 0.810 ppm |
| 2014-03-18 | S107824 | 0.580 ppm |
| 2014-03-20 | S107835 | 0.550 ppm |
| 2014-04-07 | S107846 | 0.550 ppm |
| 2014-05-06 | S107836 | 0.340 ppm |
| 2014-06-04 | S237967 | 0.150 ppm |
| 2014-07-08 | S111083 | 1.35 ppm |
| 2014-08-13 | S111084 | 0.290 ppm |
| 2014-09-16 | S238015 | 0.430 ppm |
| 2014-10-15 | S237927 | 1.13 ppm |
| 2014-11-12 | S237932 | 0.460 ppm |
| 2014-12-09 | S237937 | 0.590 ppm |
| 2015-01-08 | S107884 | 0.750 ppm |
| 2015-02-09 | S107889 | 0.400 ppm |
| 2015-03-18 | S107905 | 0.600 ppm |
| 2015-04-07 | S107897 | 0.640 ppm |
| 2015-05-05 | S107918 | 0.280 ppm |
| 2015-06-09 | S107919 | 0.750 ppm |
| 2015-07-08 | S107924 | 0.770 ppm |
| 2015-08-11 | S237942 | 0.760 ppm |
| 2015-09-09 | S237951 | 0.780 ppm |
| 2015-10-14 | S237956 | 0.270 ppm |
| 2015-11-09 | S55091 | 0.450 ppm |
| 2015-12-09 | S632505 | 0.310 ppm |
| 2015-12-18 | S654864 | 0.290 ppm |
| 2016-01-07 | S632510 | 0.380 ppm |
| 2016-02-10 | S632515 | 0.170 ppm |
| 2016-03-09 | S632520 | 0.530 ppm |
| 2016-04-13 | S632526 | 0.640 ppm |
| 2016-05-10 | S632532 | 0.530 ppm |
| 2016-06-09 | S632537 | 0.750 ppm |
| 2016-06-22 | S676750 | 0.610 ppm |
| 2016-07-13 | S632542 | 0.620 ppm |
| 2016-08-10 | S632547 | 0.240 ppm |
| 2016-09-13 | S632553 | 0.170 ppm |
| 2016-10-13 | S632562 | 0.790 ppm |
| 2016-11-15 | S632595 | 0.200 ppm |
| 2016-12-13 | S632563 | 0.150 ppm |
| 2017-01-17 | S632609 | 0.450 ppm |
| 2017-02-08 | S632460 | 0.880 ppm |
| 2017-02-16 | S693786 | 0.420 ppm |
| 2017-03-15 | S632469 | 0.490 ppm |
| 2017-04-17 | S656151 | 0.510 ppm |
| 2017-05-10 | S656152 | 0.110 ppm |
| 2017-06-13 | S656157 | 0.880 ppm |
| 2017-07-11 | S642932 | 0.470 ppm |
| 2017-08-15 | S642937 | 0.990 ppm |
| 2017-09-12 | S656162 | 0.510 ppm |
| 2017-10-17 | S653538 | 0.820 ppm |
| 2017-11-16 | S653543 | 0.890 ppm |
| 2017-12-27 | S642923 | 0.170 ppm |
| 2017-12-27 | S642924 | 0.290 ppm |
| 2018-01-18 | S642925 | 0.130 ppm |
| 2018-01-18 | S642926 | ND |
| 2018-02-14 | S653548 | 0.110 ppm |
| 2018-02-14 | S653550 | 0.740 ppm |
| 2018-03-19 | S792210 | 0.1000 ppm |
| 2018-03-26 | S653559 | 0.200 ppm |
| 2018-03-26 | S653560 | 0.200 ppm |
| 2018-04-17 | M775708 | 0.300 ppm |
| 2018-04-17 | S653561 | 0.140 ppm |
| 2018-05-09 | S653568 | 0.0914 ppm |
| 2018-05-09 | S653569 | 0.275 ppm |
| 2018-06-13 | S653574 | 0.198 ppm |
| 2018-07-11 | S656076 | 0.105 ppm |
| 2018-08-16 | S656082 | 0.167 ppm |
| 2018-09-18 | S656087 | 0.0728 ppm |
| 2018-10-17 | S632565 | 0.929 ppm |
| 2018-10-17 | S632566 | ND |
| 2018-11-15 | S632575 | 0.308 ppm |
| 2018-11-28 | S783894 | 0.255 ppm |
| 2018-12-05 | S656089 | 0.272 ppm |
| 2018-12-19 | S653583 | 0.310 ppm |
| 2018-12-19 | S653588 | 0.136 ppm |
| 2019-01-23 | S653589 | 0.252 ppm |
| 2019-01-23 | S653594 | 0.437 ppm |
| 2019-02-20 | S656061 | 0.484 ppm |
| 2019-02-20 | S656062 | 0.263 ppm |
| 2019-03-21 | S656067 | 0.326 ppm |
| 2019-03-21 | S656072 | 0.451 ppm |
| 2019-04-23 | S653595 | 0.252 ppm |
| 2019-04-23 | S653596 | 0.243 ppm |
| 2019-05-21 | S857010 | 0.348 ppm |
| 2019-05-21 | S857011 | 0.199 ppm |
| 2019-06-18 | S857016 | 0.188 ppm |
| 2019-06-18 | S857021 | 0.422 ppm |
| 2019-07-17 | S857025 | 0.315 ppm |
| 2019-07-17 | S857030 | 0.155 ppm |
| 2019-08-15 | S857031 | 0.318 ppm |
| 2019-08-15 | S857036 | 0.163 ppm |
| 2019-09-18 | S857040 | 0.342 ppm |
| 2019-09-18 | S857041 | 0.505 ppm |
| 2019-10-23 | S857051 | 0.141 ppm |
| 2019-10-24 | S857046 | 0.444 ppm |
| 2019-11-04 | S893203 | 0.319 ppm |
| 2019-11-04 | S925131 | 0.433 ppm |
| 2019-11-20 | S857059 | 0.416 ppm |
| 2019-11-20 | S857060 | 0.586 ppm |
| 2019-11-25 | S927551 | 0.407 ppm |
| 2019-11-25 | S927552 | 0.415 ppm |
| 2019-12-18 | S857061 | 0.453 ppm |
| 2019-12-18 | S857062 | 0.581 ppm |