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1. What are the sources of drinking water?

The sources of drinking water (both tap and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally-occurring minerals and radioactive material, and can pick up substances resulting from the presence of animals or from human activity.

Contaminants that may be present in source water include:
• Microbial - viruses and bacteria, which may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife
• Inorganic - salts and metals, which can be naturally-occurring as a result of urban runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming
• Pesticides or herbicides - may come from a variety of sources such as agriculture, storm water runoff, and residential uses
• Organic chemical - includes synthetic and volatile organics, which are by-products of industrial processes and petroleum production, and can also come from gas stations, urban storm water runoff, and septic systems
• Radioactive contaminants - can be naturally-occurring or be the result of oil and gas production and mining activities
In order to ensure that tap water is safe to drink, the EPA prescribes regulations that limit the amount of certain contaminants in water provided by public water systems. FDA regulations establish limits for contaminants in bottled water, which must provide the same protection for public health.

2. Why are there contaminants in my drinking water?

Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the Environmental Protection Agency’s Safe Drinking Water Hotline at 1-800-426-4791.

3. Is my drinking water safe to drink?

Yes. The Department of Water Supply makes the quality of your drinking water its number one priority. To maintain our commitment to you, we routinely collect and test water samples every step of the way-from the source waters right to your home-checking purity and identifying potential problems. We monitor your drinking water according to EPA regulations to ensure that it meets all state and federal standards. Our goal is and always has been to provide you with a safe and dependable supply of drinking water.

4. How often is my water tested?

Every week our water is tested by our certified microbiologists at the source and within the distribution system for any bacteriological contamination. Chemicals are analyzed on a timetable established by state/EPA requirements.

5. How can I get my water tested?

You can contact the County of Maui Water Supply Lab at 808-270-7550 for information about free lead testing. For more extensive testing, private labs can test your tap water for a fee. Not all labs are accredited to test for all contaminants. For information about accredited labs, call the County of Maui Water Supply Lab or the State of Hawaii Department of Health, Safe Drinking Water Branch at toll free 800-468-4644 ext. 64258.

6. Do I need to take special precautions?

Some people may be more vulnerable to contaminants in drinking water. Immuno-compromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV / AIDS or other immune disorders, some elderly, and infants can be particularly at risk for infections.

These people should seek advice about drinking water from their health care providers. You may also inquire about EPA / CDC guidelines by calling the Safe Drinking Water Hotline at (800) 426-4791.

Maui DWS water in the Upper Kula area is treated with chloramines, a disinfectant that produces fewer disinfection by-products such as trihalomethanes. As such, customers who have unique water quality needs including those who use specialized treatments such as kidney dialysis machines or fish owners should make the necessary adjustments to remove chloramines.

7. Do I need to filter my water?

Home water filters are not necessary. They can be helpful if you have lead plumbing in your home or want to remove chlorine. HOWEVER, if you choose to have a water filter, it must be maintained and replaced according to manufacturer instructions. Talk to your supplier if you have questions about your filter. Maui DWS does not monitor nor oversee the use of water treatment systems on private property.

8. What is the pH of my water?

The pH of water varies by districts:

Please see Water pH Chart for details.
Water pH Chart

9. Is there fluoride in my water?

The Maui DWS does not add fluoride to your water. If you are concerned about your children’s dental health, please talk to your pediatrician or dentist.

10. Do I have hard or soft water?

Hardness is measured in milligrams per liter (mg/L), parts per million (ppm) or grains per gallon. Hardness is caused by a combination of dissolved minerals.

Water Hardness Scale

11. What can I do about chlorine taste and odor?

Chlorine kills organisms that may cause disease. If you choose to remove the chlorine with a filter, refrigerate the water to limit bacterial re-growth. Other alternatives include: Filling a pitcher and letting it stand in the refrigerator overnight (this is the best way), filling a glass or jar with water and letting it stand in the sunlight for 30 minutes, or heating water to approximately 100 degrees Fahrenheit.

12. I live on a dead-end (cul-de-sac) and my water has a yellow tinge to it. Is this okay?

You can open all the faucets in your home until the water clears up; this will bring fresh water to your home and improve its water quality. Or if you prefer, you may call the DWS service number at 808-270-7633 to have personnel flush the dead-end main.

13. Why is my water milky?

It is understandable to be concerned about the safety of your water when it has a milky appearance, however the most common cause of milky water is tiny air bubbles and the water is safe to drink. The air bubbles can be caused by changes in pressure as the water travels from the distribution system to your household tap; water under pressure absorbs more dissolved oxygen than water that is not pressurized. Another cause of milky water can be from air trapped in mainlines. The presence of air bubbles does not affect the safety or quality of the water. Drinking water produced by the MDWS meets all Federal and State drinking water standards and is routinely tested throughout the month to ensure its compliance. The MDWS provides two barriers of protection to ensure that the water is safe from the moment of disinfection to the delivery at your household tap.

The two barriers of protection are the maintenance of steady water pressure and the maintenance of chlorine residual throughout the system. Both pressure and chlorine residual are monitored by the MDWS staff in order to ensure that our drinking water is safe and in compliance with both Federal and State drinking water standards.

• Water Pressure: A minimum pressure of 20 psi is required by regulation and the pressure in the MDWS distribution system can range from 50-160 psi depending on location. The maintenance of pressure in the distribution system prevents outside contaminants from entering into the pipes during a leak or pipe failure.

• Chlorine Residual: A minimum chlorine residual of 0.20 mg/L chlorine is maintained and the chlorine residual in the distribution system can range from 0.5-1.5mg/L depending on location. The maintenance of a chlorine residual prevents potential microbial contamination that could occur from a loss of pressure in the pipes.

In order to get rid of the appearance of air bubbles, the best thing to do is fill a pitcher with water and let it sit open to the air until all the air bubbles have disappeared. If you have any concerns about your water please call the DWS Lab at 808-270-7550

14. How can I tell if air bubbles are causing my water to look milky?

There is a simple test you can perform to verify if the milky water is due to air bubbles. First, fill a clear glass with cold water from the tap and then set it on a counter top or table. Observe the glass, the milky appearance of the water should begin to clear from the bottom of the glass as the air bubbles rise to the top of the glass. After several minutes most of the air bubbles will have disappeared and the water should look clear.

Water Comparison Test

15. How can I get my rain catchment system water tested?

Rain catchment testing is provided by the state through an accredited lab for a fee. For information about catchment systems and catchment system water testing contact the
Dept. of Health Safe Drinking Water Branch toll free at 800-468-4644 ext. 64258 or go to http://health.hawaii.gov/sdwb/raincatchment/

The University of Hawaii also provides extensive information on rain catchment systems as well as provides home testing kits for a fee. For more information, call 808-329-2861 or visit http://www.ctahr.hawaii.edu/hawaiianrain/index/html
University of Hawaii - Rain Catchment Systems

16. What other contaminants may be found in my drinking water?

• Radon - Radon is a naturally-occurring radioactive gas that you cannot see, taste, or smell. It is found all over the U.S.A. It can move from the ground into a home through cracks and holes in foundations. Compared to radon entering the home through soil, radon from tap water will be a very small source of radon in indoor air.
• Disinfection By-Products-During disinfection, certain by-products form as a result of chemical reactions between chlorine and naturally-occurring organic matter in the water. The disinfection process is carefully controlled and monitored so that it remains effective, while keeping the levels of disinfection by-products low.