The Honolulu Board of Water Supply (BWS) works hard to ensure that the water served to our customers meets or exceeds all federal and state safe drinking water standards and we want to reassure you that the water we deliver to you is safe to drink. Here are some commonly asked questions.

General FAQ

What are the Drinking Water Standards?

The Safe Drinking Water Act (SDWA) is the federal law that governs the quality of drinking water in the United States. Under the SDWA, the U.S. Environmental Protection Agency (EPA) sets standards for drinking water quality and oversees state compliance with those standards.

In Hawaii, the State Department of Health (DOH) is responsible for ensuring that all public and private drinking water suppliers comply with State and Federal drinking water standards. The ultimate responsibility rests with each water supplier to comply with the standards. The DOH and EPA is responsible to monitor and enforce these regulations.

Does the BWS test the water?

Yes. Every year, the BWS and the DOH conduct thousands of tests on the water source and distribution system to ensure that the water you receive is safe to drink. These tests check for more than 100 different types of contaminants, as required by the EPA. All final test results show the BWS is in full compliance with State and Federal standards for safe drinking water. If the water quality tests conducted did not meet State and/or Federal safe drinking water standards, the BWS would be required by law to immediately notify impacted customers and, more importantly, the BWS would stop serving that water until it met all State and Federal drinking water regulations.

Does the BWS treat the water?

Yes, the BWS treats water in accordance with all State and Federal drinking water regulations. Currently, the BWS treats drinking water with chlorine and, in certain areas of Oahu, the water is treated with granular activated carbon (GAC).

How can I find out what is in my water?

Water quality test results are shared with our customers in the annual water quality report or Consumer Confidence Report (CCR), as required by the EPA. The CCR, along with an accompanying water quality informational pamphlet, will be mailed to customers by July 1 each year. The CCR identifies where your water comes from, what regulated contaminants were found, how those levels compare to the standards for safe drinking water, and describes any treatment processes used. To get your water quality report or the water quality information pamphlet, please visit the BWS Water Quality Report webpage.

Is all of our drinking water on Oahu chlorinated?

Yes, almost all of the water pumped into the BWS water distribution system is chlorinated. Because the distribution system is interconnected, waters from chlorinated sources can mix with unchlorinated supplies. Small amounts of chlorine in the water may be found most everywhere on Oahu. Concentrations can range from zero to 0.15 milligrams per liter (ppm) of chlorine throughout the water system. Since excessive amounts of chlorine can affect the taste and odor of drinking water, the BWS adds only what is needed to keep disease-causing bacteria from contaminating our water supply.

If you experience a strong chlorine smell or taste in your water, contact the BWS Microbiological Laboratory at (808) 748-5850.

Is fluoride added to the drinking water on Oahu?

The BWS does not add fluoride to the municipal water supply. However, Federal regulations require that all military installations add both fluoride and chlorine to their water supplies regardless of water quality.

Is there lead in our water supply?

The BWS laboratory has conducted a series of tests for lead in our municipal water supply. Samples were taken from BWS sources, within the distribution system in the community, and from consumers' household taps. Based on these tests, no lead was found in any of the municipal water supplies served to Oahu's residents.

What is the pH of our water?

pH refers to the acidity or alkalinity of water and is expressed in terms of a numerical scale from 0 to 14. Seven (7) on this scale means that the water is neither acidic nor alkaline. For values less than 7, the smaller the number, the more acidic it is. For values greater than 7, the larger the number, the more alkaline it is.

The pH balance of the drinking water served by the BWS occurs naturally in the 7 to 8 range. This means that the water ranges from being neither acidic nor alkaline (pH 7) to being only slightly alkaline (pH 8).

Does the BWS conduct free tap water tests?

The BWS conducts tests at the tap only when specific water complaints—such as taste, discoloration, odor, or presence of particulate matter—are received from our customers.

If customers are curious about what is in their water, they should contact a private laboratory to have a sample analyzed. These laboratories are listed in the telephone directories under Laboratories-Analytical or can be found through a keyword search on any online search engine.

Do customers need to purchase water filter units for their homes?

The municipal water supply served to Oahu's residents is safe to drink and use, and does not require treatment by a home filtration unit.

Does the BWS offer consumer guides to home filtration systems?

The BWS does not offer any information or consumer guides on filtration systems. Customers should conduct their own research about water filter products when making a decision on whether to purchase such a system or device.

In incidents of water quality complaints, the BWS will not test water that has been altered by the installation of a filtration system. The customer may need to contact a private laboratory to have a sample analyzed, or check with the product representative or manufacturer for assistance.

Red Hill Bulk Fuel Storage Facility FAQ

Why is the Board of Water Supply (BWS) so concerned about the Red Hill Bulk Fuel Storage Facility?

The Red Hill Bulk Fuel Facility contains 187 million gallons of fuel that is located just 100 feet above a State designated drinking water aquifer. The BWS uses water from this aquifer to serve residents from Moanalua to Hawaii Kai. Navy studies show the groundwater underneath the tanks is already contaminated with petroleum chemicals. These studies also document leaks dating back to 1947, the fuel tanks wearing from corrosion and the risk of a large catastrophic fuel release. If such a release occurred, it could pollute the aquifer and our water supply for many years.

See News & Updates on Red Hill >

Why should I be concerned about Red Hill? I don't live near Red Hill or get water from wells in this area.

The situation at Red Hill poses a threat to existing BWS wells that are presently not contaminated. If these wells ever became contaminated or a catastrophic large volume of fuel got into the groundwater, then water rates would need to increase to pay for treatment to remove the contaminants from the water. If the situation involved a large release, the cost to treat would be so prohibitive as to render the wells and aquifer unusable for decades to come. The wells unaffected by the incident do not have the capacity to make up the difference resulting in long-term water moratoriums. Water rates would need to increase to pay for alternatives to take the place of the water loss. Since water rates apply to all BWS customers island wide, everyone would end up paying for what happens at Red Hill.

See News & Updates on Red Hill >

How could the wells be contaminated by a fuel leak?

Fuel from the tanks that leak into the groundwater can eventually spread to neighboring wells because the groundwater is always moving. The amount of fuel that contaminates the aquifer and how quickly it spreads depends on the volume of fuel released into the groundwater. A large volume of fuel released into the groundwater due to a major pipe or tank failure will contaminate the groundwater much faster and over a larger area than fuel that is slowly leaking from the tanks.

See News & Updates on Red Hill >

Are the BWS wells showing signs of contamination?

Not at this time. However, contamination is present in the groundwater underneath the tanks which can move in the groundwater and spread to neighboring wells in the area.

See News & Updates on Red Hill >

What contaminants are being found in the groundwater and wells?

Petroleum hydrocarbons and various related chemicals. Some of them include, total petroleum hydrocarbons as diesel (as called TPH-d), naphthalene, 1- methylnaphthalene, 2-methylnaphthalene, toluene, benzene and lead.

See News & Updates on Red Hill >

What would a worst case scenario look like?

A catastrophic fuel release could occur as the result of structural failure of the tanks caused by an earthquake. This could result in more than 1.2 million gallons of fuel released into the groundwater and 6.3 million gallons to Halawa Stream and Pearl Harbor.

See News & Updates on Red Hill >

In such a scenario, what actions would the BWS take?

The BWS would immediately shut down our Halawa Shaft and Moanalua wells. The BWS would then impose a water moratorium in Honolulu. The Navy's Red Hill Shaft would also be shut down, creating a water shortage for Pearl Harbor. A large fuel leak would render the groundwater aquifer unfit for drinking for decades as treatment alternatives in such a scenario would be ineffective and costly.

See News & Updates on Red Hill >

What is the BWS asking of the Navy?

To protect the aquifer's long-term ability to provide safe drinking water, the BWS urges the Navy, EPA, and Hawaii Department of Health (DOH) to:

  • double line the tanks. If not, then relocate away from the potable water aquifer;
  • meet the same regulatory requirements as all other USTs; and
  • clean up the fuel that is already underneath the tanks to reduce the long-term threat to other wells in the area.

See News & Updates on Red Hill >

Are the tanks still leaking jet fuel?

Yes. Tests conducted by the Navy since 2005 continue to show petroleum contaminants present in the groundwater underneath Red Hill at levels that, in one case, has exceeded Hawaii DOH environmental action limits since 2005.

See News & Updates on Red Hill >

Does the BWS have enforcement powers when it comes to protecting Oahu's water sources?

No. The Hawaii DOH has jurisdiction and regulates underground fuel tanks in Hawaii.

See News & Updates on Red Hill >

What are the health effects of these chemicals in our water?

The BWS is conducting studies to determine the health significance of low level petroleum chemicals in drinking water.

See News & Updates on Red Hill >

Are there any national environmental standards for underground fuel storage tanks?

Yes. There are federal and state regulations that apply to all underground storage tanks. However, Red Hill is a field-constructed underground tank that is deferred from many of the requirements that must be met by smaller facilities. In 2011, EPA proposed changes that would cancel Red Hill’s exemption from the rules. The proposed changes are still pending.

See News & Updates on Red Hill >

What can residents do to support the BWS in this endeavor?

Help the BWS to keep our drinking water safe by staying informed and doing your part to keep this issue top of mind.

  • Read the Administrative Order on Consent (AOC) and Scope of Work (SOW) for the Red Hill project. 
  • Stay current on news and updates about Red Hill on the BWS, EPA and Hawaii DOH websites.
  • Attend community meetings in your neighborhood about this issue and voice your concerns about protecting our groundwater resources.
  • Build awareness about Red Hill and initiatives to protect Oahu's drinking water by sharing updates and FAQ with family and friends.
  • Contact your elected officials and let them know you are concerned about Red Hill and that you support efforts to protect Oahu’s groundwater resources. For your convenience, we have listed the contact information for Hawaii's congressional delegation.

Elected Official

Honolulu Office

Washington DC Office

U.S. Rep. Colleen Hanabusa
Hawaii's 1st District
300 Ala Moana Boulevard
Room 4-104
Honolulu, HI 96850
Tel: (808) 541-2570
Fax: (808) 533-0133
422 Cannon House Office Building
Washington, DC 20515
Tel: (202) 225-2726
Fax: (202) 225-0688
U.S. Rep. Tulsi Gabbard
Hawaii's 2nd District

300 Ala Moana Boulevard
Room 5-104
Honolulu, HI 96850
Tel: (808) 541-1986
Fax: (808) 538-0233
1609 Longworth House Office Building
Washington, DC 20515
Tel: (202) 225-4906
Fax: (202) 225-4987
U.S. Sen. Mazie Hirono

300 Ala Moana Boulevard
Room 3-106
Honolulu, HI 96850
Tel: (808) 522-8970
Fax: (808) 545-4683
330 Hart Senate Office Building
Washington, DC 20510
Tel: (202) 224-6361
Fax: (202) 224-2126
U.S. Sen. Brian Schatz

300 Ala Moana Boulevard
Room 7-212
Honolulu, HI 96850
Tel: (808) 523-2061
Fax: (808) 523-2065
722 Hart Senate Office Building
Washington, DC 20510
Tel: (202) 224-3934
Fax: (202) 228-1153

See News & Updates on Red Hill >

Who are the project coordinators for Red Hill?

Here are the project coordinators for the Hawaii State Department of Health (DOH), U.S. Environmental Protection Agency (EPA), and the U.S. Navy, as well as their contact information: 


Project Coordinator

Hawaii State Department of Health
Steven Y.K. Chang, P.E., Chief
Solid and Hazardous Waste Branch
Department of Health
919 Ala Moana Blvd., Room 212
Honolulu, HI 96814
(808) 586-4226
U.S. Environmental Protection Agency
Bob Pallarino
U.S. EPA Region 9
Underground Storage Tank Program Office
75 Hawthorne Street (LND-4-3)
San Francisco, CA 94105
(415) 947-4128
U.S. Navy
Mark Manfredi
Red Hill Regional Program Director
850 Ticonderoga Street, Suite 110
JBPHH, HI 96860
(808) 473-4148

See News & Updates on Red Hill >

Chromium VI FAQ

Does the BWS test for hexavalent chromium in the water supply?

Yes. The Board fof Water Supply (BWS) tests Oahu's water supply for hexavalent total chromium in compliance with the U.S. Environmental Protection Agency's (EPA) Third Unregulated Contaminant Monitoring Rule (UCMR3). All of the results are reported in the BWS consumer confidence report (CCR) as required by the UCMR3 regulation and are within the State of Hawaii Department of Health’s action limit of 13 parts per billion (ppb). Action limits or health advisories is an estimate of acceptable drinking water levels for a chemical substance based on health effects information. It is not a legally enforceable standard. The EPA presently has no maximum contaminant limit (MCL) in drinking water for hexavalent chromium citing the present total chromium MCL as protective of human health.

Does the BWS have a MCL for hexavalent chromium for Oahu?

MCLs are established by regulatory agencies with environmental and public health risk assessment expertise such as EPA and the State Department of Health (DOH) and not BWS. These MCLs govern the quality of water supplies delivered by utilities like the BWS. The BWS is constantly in contact with federal and state regulatory agencies and national water associations to ensure we stay abreast of issues related to the safety and quality of our water supplies.

Does the BWS have a MCL for total chromium, which would include hexavalent chromium and trivalent chromium?

The BWS monitors its water supplies in compliance with the present EPA MCL of 100 ppb for total chromium. The results show our sources presently meet the current MCL for total chromium and are available on our Consumer Confidence Report (CCR), which we provide to all customers each year. Customers can access the CCRs for their areas online at:

Can the BWS test my water for hexavalent chromium?

The BWS does not perform individual testing for hexavalent chromium. If you would like to have your water tested for hexavalent chromium, please contact a private laboratory.

California became the first U.S. state to have an MCL specifically for hexavalent chromium of 10 ppb. Is this a reasonable level for drinking water?

The BWS is not a public health agency and therefore not in a position to comment on California's MCL. We recommend contacting a public health regulatory agency.

What would be the likely source of hexavalent chromium in drinking water?

According to the EPA, chromium naturally occurs in rocks, animals, plants, soil, and in volcanic dust and gases. Water sources can be affected by hexavalent chromium naturally, or through contamination plumes from industrial centers, landfills, and improper discharge of industrial processing streams. For more information, visit the EPA’s website at