Maui water system reports trace selenium levels well below safety limits

Maui County’s Department of Water Supply detected trace amounts of selenium in the Makawao water system during routine testing. Samples collected on May 29 and June 19, 2026 showed concentrations ranging from 3.7 to 4.9 µg per liter, far beneath the federal maximum contaminant level of 50 µg/L.

DWS Director John Stufflebean said the amount is “about four parts per billion – roughly four drops in a billion drops of water,” and that the levels pose no public‑health risk. The department notified the Hawaiʻi Department of Health as required and will continue monitoring the system to ensure compliance with state and federal standards. Selenium is a naturally occurring mineral that can enter water through erosion of rock and soil deposits.

Officials emphasized that the water remains safe to drink and that the water system will remain under regular surveillance.