The Hawaii State Department of Health said it found minute amounts of organic chemicals in a Haleakala National Park water system tank on Maui during routine sampling.
The organic chemicals found in the tank are total xylenes and ethylbenzene and are within compliance levels for federal and state drinking water standards, according to health officials.
"We do not want people to be alarmed. We are confident that these trace levels of chemicals do not pose a public health threat," said Gary Gill, Deputy Director for Environmental Health. "Our Safe Drinking Water Branch continues to monitor and test the water system tank that was affected and our staff is dedicated to ensuring the public receives healthy, clean water."
Total xylenes were confirmed last month at 26.9 parts per billion, which is below the federal and state Maximum Contaminant Level for total xylenes of 10,000 ppb.
Ethylbenzene was detected at 3.9 ppb, also below the federal and state MCL of 700 ppb. The federal and state standards are set to avoid health risks based on a lifetime of consuming water containing that level of contaminant.
Both total xylenes and ethylbenzene are constituents of a new epoxy coating that was applied to the 50,000 gallon water tank in December 2012. The coating is approved for use in drinking water tanks by the National Sanitation Foundation. It is expected that the concentrations of these contaminants will decrease as the epoxy coating cures in place.
This water system tank serves a population of about 1,200 people, including visitors. To date, the Haleakala National Park water system is in compliance with federal and state total xylene and ethylbenzene standards for drinking water.
The DOH Safe Drinking Water Branch safeguards public health by protecting Hawaii’s drinking water sources (surface water and groundwater) from contamination. The Branch helps to ensure that owners and operators of public water systems provide safe drinking water to the community.