| Introduction | Find Your Water Source and see Test Results | Lead and Copper | Regulated Contaminants |
| Unregulated Contaminants | Explanation of Terms | Key to Tables | Notes |
In 1998, the U.S. Environmental Protection Agency (EPA) passed new regulations requiring an annual report on the quality of drinking water be provided to customers by their community water systems. This requirement is known as the Consumer Confidence Report (CCR) rule. In July 2007 we sent out our ninth annual Water Quality Report. Look for this report in your mailbox every July.The Water Quality Report by the Maui Department of Water Supply (DWS) describes the quality of your drinking water and where it comes from. We take our responsibility to provide safe drinking water very seriously. We drink the same water as our customers and share the same concerns about its quality.
In this Report is a review of data DWS compiled while testing for more than 300 potential contaminants last year. Included are details about where your water comes from, what it contains, and how it compares to EPA and Hawaii state health standards. Also listed are phone numbers and information about how you can find out more about your water system.
The Maui Department of Water Supply has been treating and testing the quality of its water since the Department was organized in 1949. The DWS Water Quality Laboratory in Kahului is key to the Department's quality assurance program. DWS runs over 16,000 tests a year to look for more than 300 possible contaminants, many of which aren't regulated or detected. These tests ensure the safety of your water. As the charts show, very few of these substances have been found in Maui County's drinking water; all are well below allowed levels and none represent a health concern.
The Department is proud to report that the water provided by the Maui Department of Water Supply meets or exceeds established federal and state water quality standards.
For a full list of substances tested for and results, see this report or call the DWS Laboratory at (808) 270-7550.
The mission of the Department of Water Supply is to "Provide Clean Water Efficiently." This Water Quality Report is a reflection of the hard work by our 178 employees to Provide Clean Water Efficiently. Last year we provided 13.3 billion gallons of water to our customers. That's about 36 million gallons per day.
How you can find out more about your water?
If you are interested in learning more about DWS and water quality or participating in the decision-making process, there are a number of opportunities available.
The Maui County Board of Water Supply meets at least once every month. The meetings are usually held on the fourth Thursday of the month. Board meetings are open to the public. Dates, times, locations, and agendas are listed on the Board page.
Here's a list of phone numbers you can call if you have questions:
Questions about... Organization: Phone Number: Water Quality on Maui DWS Laboratory (808) 270-7550 (Maui) Board of Water Supply DWS Administration (808) 270-7816 (Maui) All other DWS inquiries DWS Administration (808) 270-8046 (Maui) Drinking Water in Hawaii Hawaii State Dept. of Health,
Safe Drinking Water Branch(808) 984-2400, extention 64258 (Toll-free from Maui) Safe Drinking Water Hotline Environmental Protection Agency (800) 426-4791 (Toll-Free)
| SECTION REPORT | SYSTEM NAME | AREAS SERVED | WATER METERS | WATER SOURCE |
|---|---|---|---|---|
| CENTRAL MAUI | Central Maui System | Wailuku, Waihee, Waikapu, Wailuku Heights, Kahului, Puunene, Kihei, Maalaea, Makena, Paia-Kuau, Spreckelsville | 18,502 | The Central System is supplied by a mix of groundwater drawn from the Iao & Waihee aquifers, Kepaniwai Well, Iao Tunnel, and filtered surface water from the Iao-Waikapu Ditch. |
| UPCOUNTRY MAUI | Makawao System | Kokomo-Kaupakalua, Kuiaha, Haiku-Pauwela, Makawao, Pukalani, Haliimaile | 6,654 | The Makawao System is supplied by surface water from the Wailoa Ditch that is treated at the Kamole Weir Water Treatment Facility (WTF), and groundwater drawn from the Po'okela, Kaupakalua, and Haiku Wells. |
| Lower Kula System | Olinda, Kula Kai, Omaopio, Pulehu | 1,092 | The Lower Kula System is supplied by surface water from seven intakes that collects at the Piiholo Reservoir and is treated at the Piiholo WTF. | |
| Upper Kula System | Upper Kula, Waiakoa, Keokea, Ulupalakua, Kanaio | 2,038 | The Upper Kula System is supplied by surface water from the Haipua'ena Intake that is stored in the Waikamoi and Kahakapao Reservoirs and is treated at the Olinda WTF. | |
| WEST MAUI | Lahaina System | Lahaina, Puamana, Wainee, Kelawea, Wahikuli, Honokowai, Mahinahina, Kahana, Alaeloa, Napili | 3,189 | The Lahaina System is comprised of two water treatment facilities. The Lahaina town area is supplied by surface water from the Kanaha Stream which is treated at the Lahaina WTF and blended with water that is pumped from the Kanaha and Waipuka Wells. In the Napili area, water from the Honolua Ditch is treated at the Mahinahina WTF and blended with water pumped from the Napili and Honokahua wells. |
| Honokohau System | Honokohau Valley | 13 | The Honokohau System is supplied by ground water from the Kapalua Water System. | |
| EAST MAUI | Hana System | Wakiu, Hana, Hamoa, Kaupo | 399 | The Hana water system is supplied by a blend of ground water from the Wakiu and Hamoa wells. |
| Keanae System | Keanae | 82 | The Keanae system is supplied by ground water from the Keanae well. | |
| Nahiku System | Nahiku | 37 | The Nahiku system is supplied by water from the Nahiku Tunnel. | |
| MOLOKAI | Kaunakakai System | Kaunakakai, Kamiloloa, Kawela | 1,146 | The Kaunakakai system is supplied by a blend of ground water drawn from the Kualapuu and Kawela wells. |
| Ualapue System | Wailua, Ualapue, Kamalo | 366 | The Ualapue system is supplied by groundwater drawn from the Ualapue wells. | |
| Kalae System | Kalae | 110 | The Kalae system is supplied by ground water from the Waikalae Tunnel and DHHL. |
Lead
Action Level: Exceeds Action Level if more than 10% of the homes tested have lead levels greater than 15 parts per billion
Maximum Contaminant Level Goal: Zero parts per billion
Source of contaminant: corrosion of plumbing systems
Copper
Action Level: Exceeds Action Level if more than 10% of the homes tested have copper levels greater than 1.3 parts per million
Maximum Contaminant Level Goal: 1.3 parts per million. Treatment techniques required.
Source of contaminant: corrosion of plumbing systems
SEE CHART FOR LEAD AND COPPER LEVELS OF YOUR AREA.
Go to our Lead and Copper page for information about our corrosion control program for Upcountry Maui.
Infants and young children are typically more vulnerable to lead in drinking water than the general population. It is possible that lead levels at your home may be higher than at other homes in the community as a result of materials used in your home's plumbing. If you are concerned about elevated lead levels in you home's water, you may wish to have your water tested. Additional information is available from the Safe Drinking Water Hotline at 1-800-426-4791.
Inorganic Contaminants
Microbiological Contaminants
Coliforms are bacteria which are naturally present in the environment and are used as an indicator that other, potentially harmful bacteria may be present. If coliforms are found in samples, this could signal a warning of potential problems. Chlorine levels would be raised and extensive bacteriological testing conducted to monitor the systems. See the chart for your area for coliform levels, if any.
Radiological Contaminants
Synthetic Organic Contaminants
Volatile Organic Contaminants
Drinking water rules require DWS to monitor for certain unregulated contaminants. Testing detected the following unregulated contaminants. See the charts for your area for specific details and locations.Unregulated Radiological Contaminants
Unregulated Disinfection By-products
Maximum Contaminant Level (MCL):
The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to
the MCLGs are feasible using the best available treatment technology.
Maximum Contaminant Level Goal (MCLG):
The level of a contaminant in drinking water below which there is no known or expected risk to health.
MCLGs allow for a margin of safety.
Parts per million (ppm) or milligrams per liter (mg/L):
One part per million corresponds to one second in 11.5 days.
Parts per billion (ppb) or micrograms per liter (ug/L):
One part per billion corresponds to approximately 1 second in 31.7 years.
Action Level (AL):
The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which
a water system must follow.
Treatment Technique (TT):
A required process intended to reduce the level of a contaminant
Colony Forming Units (CFU):
A measurement used to count the number of bacteria colonies found in water
Nephelometric Turbidity Units (NTU):
A measure of suspended particles in water. High quality water has a low NTU.
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.
How do I know my water is safe to drink?
To ensure that tap water is safe to drink, EPA prescribes limits on the amount
of certain contaminants in water provided by public water systems. Federal
regulations establish limits for contaminants in bottled water.
Why all the testing? Is my water contaminated?
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
EPA Safe Drinking Water Hotline at 1-800-426-4791.
What contaminants might be in my 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:
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 system disorders, some elderly,
and infants can be particularly at risk from infections. These people should seek advice
about drinking water from their health care providers. EPA/CDC guidelines on appropriate
means to lessen the infection by cryptosporidium are available from the Safe Drinking Water
Hotline at 1-800-426-4791.
For more information on contaminants, check out the Environmental Working Group National Tap Water Quality Database