Trace levels of contaminant detected in one O‘ahu water system during routine testing. Water remains
HONOLULU – Trace levels of the chemical 1,2-Dibromo-3-chloropropane (DBCP) were recently detected in water samples collected at a Waipahu-Ewa-Waianae water system (Waipahu Wells IV) well during routine testing. Drinking water from this well remains safe, as the trace levels detected were far below the U.S. Environmental Protection Agency (EPA) and State Maximum Contaminant Level (MCL) for DBCP. In addition, DBCP is filtered out through the Honolulu Board of Water Supply’s Granular Activated Carbon treatment facilities before being delivered to consumers.
“These trace levels of chemical are so small that it does not pose a public health threat, and the water filtered from this well is safe to drink,” said Keith Kawaoka, Deputy Director for Environmental Health. “The Department of Health will continue to work together with the Honolulu Board of Water Supply, to ensure tests for this chemical continue. Such testing is part of the scheduled monitoring regularly conducted to ensure that everyone’s water is safe and public health is not compromised.”
The DBCP level confirmed at the Waipahu Wells IV well was 0.011 parts per billion. This trace level was approximately one-twentieth of the EPA MCL of 0.2 parts per billion. The state of Hawai‘i has a more stringent MCL of 0.04 parts per billion, and the concentration found was also lower than the state’s more stringent level. EPA defines the MCL as the highest level of a contaminant that is allowed in drinking water. The standards are set to avoid human health risks based on a lifetime of consuming water containing that level of contaminant.
DBCP was a soil fumigant and nematicide that was used in pineapple cultivation.
The Honolulu Board of Water Supply conducts tests at sources and treatment facilities as mandated by federal and state drinking water regulations. To date, the Waipahu-Ewa-Waianae water system continues to be in full compliance with all federal and state standards for drinking water.