8570 Executive Park Avenue, Fairfax, VA 22031  703.698.5600   |   After Hours Emergencies 703.698.5613, TTY 711

EPA Drinking Water Regulations


Frequently Asked Questions

1. How "hard" is our water?
Typically, our water is "moderately hard" to "hard" (5 - 10 grains per gallon, or 84 - 170 mg/l). Click here for more information about water hardness.


2.  Is the fluoride in my drinking water safe?

In correct amounts, added and naturally occurring fluoride has improved the dental health of American consumers. Fairfax Water’s current treatment target is 0.7 mg/L of fluoride. For more information click here.


3.  I live in an apartment and my water bill is included in my rent.   How can I receive information concerning my tap water?

Fairfax Water publishes several information fliers that are included within the bill. Talk to your apartment manager and ask that any included information be posted for everyone to read. In addition, Fairfax Water’s Annual Water Quality Report is sent to all addresses within our distribution system regardless if a bill is received at the address.


4.  Is it safe to drink water from a garden hose?

Substances used in vinyl garden hoses to keep them flexible can get into the water as it passes through the hose.  These substances are not good for you or your pets. There are hoses made with “food­grade” plastic that will not contaminate the water. Check your local hardware store for this type of hose.


5.  Can water straight from the tap be used in home kidney dialysis machines?

Tap water must go through further treatment in order to be used in a dialysis machine.  Because the water comes into close contact with a patient’s blood, several substances like aluminum, fluoride, and chloramines must be removed from the water before it can be used.


6.  How are bacteria that can make people sick kept out of drinking water?

Chemicals called disinfectants are added to drinking water at the treatment plant. Fairfax Water’s primary disinfectant is chlorine and its chemical compounds. Chloramine, the combination of ammonia and chlorine, form a stable bond that keeps a disinfectant residual throughout the entire distribution system. During the spring months, Fairfax Water performs its annual flushing. While that program is in progress, the disinfectant is changed to free chlorine. Free Chorine is an aggressive disinfectant that aids in the disinfection of the flushed water mains. Fairfax Water is also beginning to utilize ozone as a disinfectant. The use of ozone will allow the amount of chloramine and free chlorine added in the treatment process to be reduced.


7.  Is the amount of chemicals found in the drinking water harmful?

In fact some chemicals like fluoride are added to the drinking water to directly benefit the consumer. Minerals may also be beneficial and many chemicals have no adverse effects on public health.


8.  Is water with chlorine in it safe to drink?

Testing has proven that the amount of chlorinated disinfectants found in drinking water is safe to drink.


9.  I sometimes get a pink stain on my bathroom fixtures, and in my pet’s water bowl. What is it and how do I get rid of it?

The pink stain (sometimes slimy in the way it feels) is generally a mixture of non-pathogenic bacteria. These bacteria are believed to be airborne and multiply in damp environments. Commercial cleansers containing bleach are effective in killing the bacteria and getting rid of the stain.


10.  All of the strainers in my faucets are clogging with white particles.  What could this be?

These white particles are very likely to be pieces of the dip tube from your hot water heater. Several brands of hot water heaters manufactured in the 1980’s were made using a faulty dip tube that disintegrates over time. The dip tube carries the cold water from the top of the hot water heater to the bottom, where the cold water is heated. Over time, the dip tube disintegrates and the white dip tube particles are carried through the household pipes. If the particles are large enough they are caught in the strainers of the sink faucets or showerheads. Since it is only a hot water concern, these particles will only be found in places where hot water travels; so the toilet bowls and tanks, and automatic ice maker will not contain these particles if indeed they are from the dip tube. If you are experiencing a problem of this nature, call the manufacturer of your hot water heater for further information.


11.  Who makes the rules and regulations for drinking water?

Regulations are made by both federal and state agencies. The Safe Drinking Water Act (SDWA) passed by Congress in 1974 and amended in 1986 and 1996 is governed by the United States Environmental Protection Agency (USEPA) http://www.epa.gov/safewater/standards.html 

Within the EPA, the Office of Ground Water and Drinking Water administers the drinking water program under the Public Water Supply Supervision Program. Their functions include:

  • Setting the maximum contaminant levels (MCL’s) for contaminants in drinking water and setting other requirements to ensure that drinking water is safe.
  • Delegating primary enforcement responsibilities to the states. Monitoring state activities to ensure that regulations are being met. 
  • Operating the program in states that have not accepted primary enforcement responsibility. 
  • Providing for continued research on drinking water contaminants. 
  • Providing technical assistance to the states.
  • Provided for in the SDWA, is the intent that states accept primary responsibility for enforcement of the states drinking water program (primacy). Under these provisions, each state must establish requirements for public water systems at least as stringent as those set by the EPA. In Virginia, the agency is the Virginia Department of Health.

    In addition to the SDWA, the EPA has promulgated several specific rules to address various types of water contaminant problems.  Some of these rules are: Surface Water Treatment Rule, Total Coliform Rule, and the Lead and Copper Rule.

12.  Why does tap water sometimes look milky or opaque?

During the time of year when the water coming into the house is colder than the temperature inside the house, this phenomenon can occur. Cold water holds more oxygen than warm water does, consequently when the cold water from the water mains outside comes inside our warm homes, and the water begins to warm, the oxygen has to escape. It does so by bubbling out in air bubbles which makes the water look milky. A visual example of this is to run water into a clear container and observe for a short time. If the water clears from the bottom to the top of the container then the phenomenon described is occurring. The air bubbles are moving from the bottom to the top of the container to escape into the open atmosphere.


Click here for more information including a visual presentation.


13.  Can I store drinking water indefinitely and it continue to be safe to drink?

The disinfectant in drinking water will eventually dissipate even in a closed container. If that container housed bacteria prior to filling up with the tap water the bacteria may continue to grow once the disinfectant has dissipated. Some experts believe that water could be stored up to six months before needing to be replaced. Refrigeration will help slow the bacterial growth.


14.  Is it okay to use water from the hot water tap for drinking, cooking, or making baby formula?

Hot water generally comes from a hot water heater that may contain impurities that should not be ingested. Some of these impurities might be metals from household plumbing that are concentrated in the heating process. Additionally, these impurities from the household plumbing dissolve more rapidly in hot water than cold water causing the amount of impurities to be higher in hot water.


15.  Sometimes ice cubes made from the tap water, or the melted water from ice cubes contains white particles.  What are these particles and where do they come from?

Ice cubes freeze from the outside in. Ice is formed from pure water (hydrogen and oxygen) therefore the minerals such as calcium and magnesium normally found in the water sometimes end up as visible particulates in the core of the ice cube. The white particles are not toxic.


16.  What is the white residue sometimes found on items such as coffee pots, irons, shower doors, glassware, and cookware?

The white residues are minerals that are found in the water such as calcium. Over time and repeated water use there may be a build-up of the minerals on any item the water comes in contact with. There are commercial products that can be purchased to rid the surface of mineral build-up.


17. Do I need to treat the tap water in any way before I place fish in an aquarium?

The chlorine that Fairfax Water uses for disinfection can be harmful to fish if not dechlorinated before placing in your aquarium. Fairfax Water uses two types of chlorine: free chlorine from April to June as part of our annual flushing program and chloramines the rest of the year, which is a chlorine and ammonia mixture. Free chlorine and chloramine dechlorination is performed differently. Chemical additives with directions for dechlorinating either free chlorine or chloramine from water for use in fish tanks or ponds are available at pet/fish supply stores.


18.  How is the water tested, and by whom?

Fairfax Water’s Water Quality Laboratory, a state certified laboratory, performs or manages the testing required by State and Federal regulations. In addition to regulatory testing many other analyses are performed to monitor the water quality of the Authority’s raw sources, water within the treatment process, as well as within the distribution system. Water undergoing the treatment process is continuously monitored for pH, turbidity, coagulation efficiency, and disinfectant residuals through technically advanced on-line monitoring systems. Other testing, such as chlorine, pH, and temperature, is performed at the sample location site with portable instrumentation. The majority of the regulatory and water quality monitoring testing performed, which include Organic, Inorganic, Metals, and Bacteriological testing, are conducted at Fairfax Water's laboratory using sophisticated instrumentation. Results for much of this testing are posted on Fairfax Water’s website in its Annual Water Quality Report.



Page Last Updated: 1/5/2011