The Board of Water Supply (BWS) is committed to protecting public health and takes seriously any information about potential drinking water contaminants.  On December 20, 2010, the Environmental Working Group (EWG) released a report about the presence of Chromium VI (hexavalent chromium), a suspected carcinogen, in water supplies around the country.

The U.S. Environmental Protection Agency (EPA) is currently evaluating the health effects data on Chromium VI (hexavalent chromium).  BWS is prepared to respond to any new requirements to ensure our water meets all federal and state drinking water standards.

Below are some frequently asked questions:

1.  The Environmental Working Group took a single sample of the water supply in Honolulu and found 2 parts per billion (ppb) of hexavalent chromium in the water. What is the BWS doing about this?

The BWS collected and tested dozens of water samples in consultation with the State Department of Health (DOH) to determine the extent of hexavalent chromium presence in our water supply.  The BWS recently concluded its initial testing program and the information collected will help us better understand hexavalent chromium occurrence in our water sources island wide.

Click here for results from the island wide testing program conducted from January through July 2011.

Click here for a link to the DOH news release on the initial island-wide screening for hexavalent chromium.

2. Based on the results of the recent hexavalent chromium tests, is Oahu's tap water safe to drink?

Yes.  According to the DOH, the BWS's drinking water supply continues to meet all state drinking water standards and is safe for human consumption.  According to the Department of Health, the recent hexavalent chromium test results are within the expected range of naturally occurring levels for Hawaii.

3. Why didn't the BWS test for hexavalent chromium in the water supply earlier?

The BWS monitors our water supply for total chromium in conformance with the U.S. Environmental Protection Agency's (EPA) total chromium maximum contaminant level (MCL) of 100 ppb for drinking water.  Total chromium includes hexavalent and trivalent forms.  The EPA presently has no MCL for hexavalent chromium citing the present total chromium MCL as protective of human health.

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 on our website, www.boardofwatersupply.com.

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

MCLs are established by agencies with environmental and public health risk assessment expertise such as EPA and the DOH.  These MCLs are then promulgated into rules that 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.

5. Can the BWS test my water for hexavalent chromium?

The Board of Water Supply (BWS) cannot test for hexavalent chromium at this time.  The BWS is collecting water samples and sending the samples to an independent laboratory in California to determine the extent of hexavalent chromium presence in our water sources.  

If you would like to have your water tested for hexavalent chromium, you can contact a private laboratory to test the water from your property at your own expense.

6. 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.

The levels and source of hexavalent chromium in our water supply are not known at this time.  We are hoping that the tests we plan to conduct will provide a better indication of the levels in our sources.

For more information, visit the EPA's website at http://www.epa.gov/.