Fact Sheet: Private Well Water and Fluoride FAQs
This fact sheet addresses questions that consumers may have on fluoride
levels in groundwater from private wells.
How do I know if my water is from a public water system or a private
well?
The U.S. Environmental Protection Agency defines a Public Water System as a
system that serves 25 or more people per day. If you have water service from
a well that has a limited delivery, such as to your house but not to your
neighbor’s house, then you likely have a private well.
What are the governmental regulations for private wells?
Although most U.S. households are connected to a public water system, the
U.S. Geological Survey estimates that approximately 15% of U.S. residents
rely on private wells that are not regulated by EPA Safe Drinking Water Act.
In most states, private wells are not regulated by governmental regulatory
entities. Therefore, it is the responsibility of the homeowner to know and
understand the quality of the water from their well. The U.S. Environmental
Protection Agency suggests that all wells should be tested for quality once
every three years since influences to well water quality can change over
time. Contact your public health office for their advice on testing of
private wells in your state or area. Additional information on testing well
water quality in private wells serving homes can be found on the
U.S.
Environmental Protection Agency Web site.
My home gets its water from a private well. What do I need to know
about fluoride and groundwater from a well?
Fluoride is present in virtually all waters at some level, and it is
important to know the fluoride content of your water, particularly if you
have children. If you have a home well, it is recommended to have a sample
of your water analyzed by a laboratory. Check with your dentist, physician,
or public health department to learn how to have your home well water
tested.
What should I do if the water from my well has less fluoride than what
is recommended ( 0.6 mg/L)? Can I add fluoride?
The optimum fluoride level in water for good oral health is between 0.7 to
1.2 mg/L (milligrams per liter). If you have water fluoride levels under 0.6
mg/L, your child's dentist or pediatrician should evaluate whether your
child can benefit from daily fluoride supplements. Their recommendation will
depend on your child's risk of developing tooth decay and as well as
exposure to other sources of fluoride (e.g., drinking water at school or
daycare, toothpaste). It is not feasible to add fluoride to an individual
residence’s well.
What should I do if the water from my well has fluoride over 1.2 mg/L?
Drinking water with fluoride levels greater than 1.2 mg/L is higher than the
optimum recommendation. Fluoride levels greater than 1.2 mg/L continue to
provide beneficial protection against tooth decay, but at increased levels
children aged 8 years and younger that are still developing teeth will have
an increased chance of developing
enamel fluorosis. If your water has a fluoride level greater than 2 mg/L
but less than 4 mg/L, you should consider an alternate source of drinking
water for young children. Adults and children older than age 8 years can
safely consume the water at these levels, If the fluoride content in your
well water is greater than 4 mg/L, consider an alternate source of water for
your family, or install a device to remove the fluoride from the water.
What should I do if my well water was measured as having too much
fluoride (level greater than 4 mg/L)?
It is unusual to have the fluoride content of water exceed 4 mg/L. If a
laboratory report indicates that you have such excessive fluoride content,
it is recommended that the water be retested. At least four samples should
be collected, a minimum of one week apart, and the results compared. If one
sample is above 4 mg/L and the other samples are less than 4 mg/L, then the
high value may have been an erroneous measurement. If all samples register
excessive levels greater than 4 mg/L, then you may want to consider
investigating alternate sources of water for drinking and cooking, or
installing a device to remove the fluoride from your home water source.
Physical contact with high fluoride content water, such as bathing or
dishwashing, is safe since fluoride does not pass through the skin.
What are the health risks of consuming water with fluoride levels
greater than 4 mg/L?
Children aged 8 years and younger have an increased chance of developing
severe tooth enamel fluorosis. Consumption over a lifetime may increase the
likelihood of bone fractures, and may result in skeletal fluorosis, a
painful or even crippling disease. The U.S. Environmental Protection Agency
has determined that safe exposure of fluoride is below 4 mg/L in drinking
water to avoid those effects. The National Research Council recently
completed a report on health effects of excessively high fluoride
consumption, and CDC has a Statement on
the 2006 National Research Council (NRC) Report on Fluoride in Drinking
Water .
Will using a home water filtration system take the fluoride out of my
home’s water?
Removal of fluoride from water is difficult. Most home point-of-use
treatment systems that are installed at single faucets use activated carbon
filtration, which does not remove the fluoride. Reverse osmosis point-of-use
devices can effectively remove fluoride although the amount may vary given
individual circumstances. For a home point-of-use device to claim a
reduction in fluoride, it must meet National Sanitation Foundation (NSF)
Standard 58 criteria for fluoride removal. Standard 58 requires that a
device must achieve a 1.5 milligrams per liter (mg/L) concentration in the
product water if the original concentration was 8.0 mg/L, or approximately
80 percent removal. This percentage removal may not be consistent at lower
concentrations of fluoride. Check with the manufacturer of the individual
product for specific product information. Fluoride is not released from
water when it is boiled or frozen. One exception would be a water
distillation system. These systems heat water to the boiling point and then
collect water vapor as it evaporates. Water distillation systems are
typically used in laboratories. For home use, these systems can be expensive
and may present safety and maintenance concerns.
Can I use water with fluoride for preparing infant formula?
Yes. People have used optimally fluoridated tap water to prepare infant
formula for many years. However, if your infant is exclusively consuming
formula reconstituted with optimally fluoridated water (0.7 to 1.2 ppm or
mg/l), there may be an increased potential for them to develop mild dental
fluorosis on their developing teeth. Consult with your pediatrician for
proper infant formula feeding advice. Additional information can be found in
a fact sheet on Infant Formula.
Page last reviewed: October 31, 2008
Page last updated: April 25, 2008
Content source:
Division of Oral Health, National Center for Chronic Disease Prevention and
Health Promotion. |