Honolulu Board of Water Supply finds potentially hazardous chemicals in drinking water
Chemicals used to make pesticides, waterproof carpets, and stain-resistant cookware have been detected in drinking water on Oʻahu.
Trace levels of dieldrin and perfluoropentanoic acid (PFPeA) were identified in the Pearl City Shaft and Aina Koa Well I. Both drinking water sources are part of the Honolulu-Windward-Pearl Harbor water system.
Health officials say drinking water from these areas is safe. The levels detected were far below health advisory limits.
The Department of Health health advisory for dieldrin is 0.2 micrograms per liter (ug/L). The detected levels in the Pearl City Shaft ranged from 0.0109 ug/L to 0.0121 ug/L.
Dieldrin is an organic chemical once used as a pesticide for controlling ground termites and may occur in drinking water by leaching into groundwater.
In April 2021, the DOH established a drinking water environmental action level for PFPeA- of 0.80 ug/L. The PFPeA level confirmed at the Aina Koa Well I ranged from 0.002 ug/L to 0.003 ug/L.
PFPeA can be used to make carpets, clothing, fabrics for furniture, paper packaging for food, and other materials designed to be waterproof, stain-resistant, or non-stick.
The state Department of Health and the Honolulu Board of Water Supply said they will continue to test the drinking water for potentially hazardous chemicals.