PCBs found in Princeville water tank officials say water does not pose a threat
HONOLULU — The Hawai‘i State Department of Health announced Friday that a chemical contaminant was found in a drinking water reservoir in Princeville. The department also states that water distributed from the drinking water system, which serves about 1,700 people, “does not pose a health threat and continues to be safe.”
On Oct. 16, during a sampling of drinking water across the state, DOH found trace amounts of the organic chemical Aroclor 1254, a polychlorinated biphenyl (PCB), the release states.
PCBs are a group of organic chemicals formerly used in the United States in hydraulic fluids, plasticizers, adhesives, fire retardants, and de-dusting agents, and PCBs do not dissolve well in water, the DOH says.
The department learned on Nov. 8 that an oily sheen containing PCBs was also discovered in a sample skimmed from the surface of a tank of water at 18 parts per billion. Since water exits from the bottom of the tank and PCBs do not dissolve well in water, this does not represent a health threat, according to the DOH.
The DOH instructed the Princeville Utilities Company Inc., owner and operator of the Princeville water system, to conduct testing to determine if PCBs were present and to identify the possible source of contamination.
PUCI sent water samples collected on Oct. 23 and 24 to CalScience Laboratory in California for testing. PCBs were not detected at the tank’s compliance sampling point where water exits at the bottom of the tank or at the two wellheads that supply the tank.
The DOH collected and tested weekly samples at the compliance sampling point and throughout the distribution system on Nov. 14, 19 and 27 and Dec. 4. No PCBs were detected in the samples analyzed by the state Laboratories Division, the release says.
“Fortunately, our follow up testing indicates that PCBs are not found in the water that reaches people’s homes,” says Gary Gill, Deputy Director for Environmental Health. “Our Safe Drinking Water Branch is maintaining active surveillance of the distribution system and will continue to monitor and test the water being served to consumers to ensure that the public is protected.”
Additional water testing is continuing and PUCI is removing the oily sheen from the tank water surface discovered last month. On Nov. 30, subsequent testing of the sample confirmed the presence of PCBs in the surface sheen at 1.38 ppb. Sampling on Dec. 6 revealed the concentration of PCBs in a skim sample was 1.4 ppb. For more information on PUCI’s mitigation measures, contact Mike Loo at (808) 826-6100.
The source of the oily sheen is still undetermined. Upon findings of PCBs in the oily sheen sample, PUCI immediately took Well No. 1, an oil-lubed well, out of service. PUCI tested previously used and currently used pre-lube oils used to lubricate Well No. 1. On Nov. 30, PUCI confirmed that neither of these oils contains PCBs. Well No. 2 is water-lubed and therefore was not at issue.
The federal and state Maximum Contaminant Level for PCBs is 0.5 ppb at the compliance sampling point. The standard is set to avoid health risks based on a lifetime of consuming water containing that level of contaminant.