FREQUENTLY ASKED QUESTIONS

The most common reason for discolored water is iron. Many of Oʻahu’s water mains are made of iron, and disturbances from construction or water main breaks may cause the water to become temporarily discolored from its presence.

As a nuisance contaminant, iron levels are recommended to be beneath a secondary maximum contaminant level (SMCL) by the EPA. EPA does not enforce SMCLs. They are established as guidelines to assist public water systems in managing their drinking water for aesthetic considerations, such as taste, color, and odor. These contaminants are not considered to present a risk to human health at the SMCL.

If a customer notices any discoloration in their water, flushing out property lines usually addresses this concern. Simply run a large faucet (like a bathtub) or hose bib for a few minutes to get rid of the color. If the issue persists, customers may call the BWS 24-hour water trouble line at (808) 748-5000, ext. 1 for further instruction or assistance.

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.

The U.S. Geological Survey (USGS) categorizes hardness into the following ranges:

Water sources across Oʻahu may have hardness values between 25 and 300 parts per million (ppm). The hardness level at an address may vary depending on factors such as which pumps are in service. For questions about hardness, the Water Quality Department may be reached at (808) 748-5840.

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 Hawaiʻi, 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 are responsible for monitoring and enforcing these regulations.

Yes. Every year, the BWS conducts 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 91 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 meets all State and Federal drinking water regulations.

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 Oʻahu the water is also treated with granular activated carbon (GAC).

Yes, all of the water pumped into the BWS water distribution system is chlorinated. Concentrations ranging from 0.25 to 0.5 milligrams per liter (ppm) of chlorine can be found 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.

In accordance with federal and state regulations, the BWS tests for lead in water samples taken from consumers' household taps. Based on these tests, our water supply meets the standard for lead in drinking water.

Water quality test results are shared with our customers in our 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 you 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 informational pamphlet, please visit http://www.boardofwatersupply.com/water-quality/water-quality-report.

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

We can mail you a copy or you may get a copy of the Water Quality Report for your service address from the Water Quality section of the BWS website.

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).

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

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.

Large buildings planning to reopen for business should follow the Centers for Disease Control and Prevention (CDC) guidelines for flushing water lines at facilities where there has been low to no water use.

• Centers for Disease Control and Prevention:
  https://www.cdc.gov/coronavirus/2019-ncov/php/building-water-system.html

Additional Resources:

• American Water Works Association:
  https://www.awwa.org/Resources-Tools/Resource-Topics/Coronavirus#10681543-shutoffs-and-return-to-service-guidance
• Environmental Science, Policy & Research Institute:
  Flushing Guidance for Periods of Low or No Use (PDF)
• Hawaiʻi Department of Health Safe Drinking Water Branch:
  Call: (808) 586-4258

The Cross-Connection Control Section (CCCS) is part of the Board of Water Supply's (BWS's) Customer Care Division. It reviews constructions plans for cross-connection control (CCC), conducts field inspections of backflow prevention assembly (BFPA) installations tests the Board's own backflow prevention assemblies, conducts customer education on the importance of cross-connection control and manages the Board's Annual Backflow Prevention Assembly Testing Program.

A cross-connection is a connection between a public water system or consumer's potable (i.e., drinking) water system and any source or system containing nonpotable water or other substances.

Backflow is the flow of nonpotable water or other substances through a cross-connection and into the piping of a public water system or consumer's potable water system.

A backflow prevention assembly is a mechanical device installed in your private property after the water meter. It prevents water already in your property pipes from "backflowing" into the City water system, possibly contaminating the City's potable water system.

Yes, there are several different types of backflow preventers available:

• Air Gap (AG)
• Reduced Pressure Backflow Prevention Assembly (RP)
• Double Check Backflow Prevention Assembly (DC)
• Pressure Vacuum Breaker (PVB)
• Atmospheric Vacuum Breaker (AVB)
• Spill-Proof Pressure Vacuum Breaker (SVB)

The Board of Water Supply recognizes all of these - except the AVB - as acceptable forms of cross-connection control because they can be tested and repaired in-line.

A Certified Backflow Prevention Assembly Tester must test the device. The certified tester will test your new backflow prevention assembly to ensure that it works and will then fill out a Backflow Prevention Installation and Test form. This form should have been given to you that you when construction plans were being processed for a building permit. The Installation and Test form will be given to you from the Certified Tester. You must sign the bottom portion of the form (Assembly Owner Signature), make a copy for your records and mail, fax or email the completed form to:

Board of Water Supply
Cross-Connection Control Section
630 South Beretania Street
Honolulu, HI 96843
Fax: (808) 550-5550
Email: cccs@hbws.org

Backflow prevention controls two types of hazards: pollution and contamination of your drinking water supply. A pollutant is any substance which affects the color or odor of the water, but does not pose a health hazard. A contaminant causes illness or death when ingested.

To ensure that the device is functioning properly. With the exception of the air gap, BFPAs are mechanical units that have internal seals, springs, and moving parts that are subject to fouling, wear, or fatigue. The annual test ensures a properly functioning BFPA, and certifies that the BFPA has not been removed or had a by-pass line installed around it. Air gaps may be tested by conducting a visual inspection.

No, but that is the preferred location. The backflow prevention assembly must be installed on "private property." If the backflow prevention assembly cannot be installed immediately behind the meter, the Board of Water Supply (BWS) will allow the BFPA to be installed somewhere more convenient within the property, but the location must be approved by the CCCS. There can be no connections to the water line between the meter and the BFPA. If the water line passes through a landscaped area, the BWS requires the water line to be concrete jacketed.

No, because this allows the assembly to become submerged in the underground box or vault. It also poses safety hazards to the individual testing and maintaining the BFPA.

Call the Cross-Connection Control Section at (808) 748-5470 and request that a copy be emailed, faxed or mailed to you. You will need your water bill account number or the backflow preventer ID number so the correct test form can be sent to you.

The Board of Water Supply (BWS) requires a Reduced Pressure Principle Backflow Prevention Assembly (PR) to be installed immediately behind your meter and in front of any trees or branches. The installation of the RP must be verified by one of the CCCS technicians prior to conversion to Agricultural Water Rate.

Cross-connection control requirements for irrigation systems serving single-family detached dwellings are under the jurisdiction of the City's Department of Planning and Permitting.

Yes. The CCCS will work with you and try to find the best location or solution for your particular place of business.

The Board of Water Supply (BWS) maintains a database containing all of the permitted backflow devices on Oahu. When your device is due to be tested, the BWS will notify you and provide you with a list of certified backflow prevention assembly testers. It is the customer's responsibility to schedule the test. The customer will also be provided with a backflow prevention device test form.

Failure to install the required type of BFPA could result in termination of water service as indicated in the Board of Water Supply (BWS) Rules and Regulations Section 2-213. The BWS will work with you to have the required BFPA installed.

Yes. In compliance with the EPA Third Unregulated Contaminant Monitoring Rule (UCMR3), the Board of Water Supply (BWS) tested Oʻahu's water supply for hexavalent chromium. All results are reported in the BWS consumer confidence report (CCR) as required by the UCMR3 regulation and are within the DOH’s action limit of 13 parts per billion (ppb). Since completing the UCMR3 testing requirements, BWS has elected to conduct annual testing of its water sources for hexavalent chromium. 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 level (MCL) in drinking water for hexavalent chromium citing the present total chromium MCL as protective of human health.

MCLs are established by regulatory agencies with environmental and public health risk assessment expertise such as EPA and the 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.

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 http://www.boardofwatersupply.com/water-quality/water-quality-report.

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.

The BWS is not a public health agency and therefore not in a position to comment on California's MCL. We recommend visiting the California State Water Resources Control Board website for more information on California's hexavalent chromium MCL.

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 http://www.epa.gov/.

There is no way of really knowing where the PFAS came from. PFAS have been around since the 1940s with ramped up use in many products since the 1960s. PFAS was used to make nonstick cookware, water-repellent clothing, stain resistant fabrics and carpets, some cosmetics, and firefighting foam. What we can do is to continue monitoring to ensure that the levels either stay static or disappear. We are currently testing for PFAS at levels that are extremely low. This helps us do a better job of monitoring when we do get a hit in one of our wells.

The use of home filtration device is an individual choice. As a government agency, we are precluded from endorsements for products. If you choose to use a home filtration device, we recommend you thoroughly know what your device can and cannot remove from the water to maintain the system in accordance with the manufacturer’s instructions.

The BWS will continue to monitor and provide data as it comes available. We take our kuleana seriously to provide safe drinking water to our community. We are working on a new section for our website with PFAS information on it including information on the detections at BWS sources. We will send out a news release when ready. We hope this information will be of use to the community as this is an important and serious issue.

The BWS can't speak to the Armory issues but understand they will be testing wells and some lo'i. We have asked that they test the streams in the area as well.

The BWS has been testing all of our wells across the island since 2020 and have had 4 hits – none in the Pearl City area. We had very low level hits at the following wells: Hālawa (2020 and 2023), ʻĀina Koa (2021), Waipahu (2022), Makakilo (2023), Moanalua (2023), and Waipio (2023). With the discovery at the Armory, we will be testing weekly and have just taken new samples which are at the lab on the mainland.

The BWS has its own resources but not close to the Armory area.

BWS conducted PFAS testing on all BWS sources once annually from 2020 to 2022. Starting in 2023, BWS is testing all sources twice annually in accordance with UCMR5. Hālawa Wells and Moanalua Wells are being tested weekly as part of the BWS Red Hill crisis monitoring and Waipio Heights Wells is being tested weekly in response to the Hawaiʻi Army National Guard Waiawa facility (HIARNG) PFAS site investigation. Other BWS wells close to the HIARNG facility that are also being tested weekly are Pearl City Shaft, Pearl City Wells I, Pearl City Wells II and Manana Well. Waipio Heights Wells I is the sixth well station in the area but is presently down for repair and not operational.

If you choose to test your water yourself, it is important to use a state-certified laboratory using EPA-developed testing methods. The Hawaiʻi Department of Health maintains a list of certified labs. You may also consider installing in-home water treatment (e.g., filters) that are certified to lower the levels of PFAS in your water.

The EPA offers guidance about minimizing your risks at the following website: https://www.epa.gov/pfas/meaningful-and-achievable-steps-you-can-take-reduce-your-risk