# Selenium detection in Maui water systems > Live situation record from CLSTR: https://clstr.news/situations/selenium-detection-in-maui-water-systems > Updated: 2026-08-11T02:30:00.000Z. Sources: 2. Developments: 2. Routine water quality testing in Maui County has identified trace amounts of selenium in two different water systems. In the Makawao water system, testing conducted in late May and June 2026 detected concentrations between 3.7 and 4.9 µg/L. Maui County Department of Water Supply Director John Stufflebean described the levels as “about four parts per billion – roughly four drops in a billion drops of water,” noting they pose no public health risk. Subsequent testing in the Wailuku water system, which serves Maalaea, Kihei, Wailea, and Makena, revealed selenium levels ranging from 2.4 to 6.5 micrograms per liter. Officials from both systems emphasized that these findings are well below the federal and state maximum contaminant level of 50 µg/L. Selenium is a naturally occurring mineral that can enter water through the erosion of rock and soil. The Department of Water Supply has notified the Hawaiʻi Department of Health and will continue monitoring both systems to ensure compliance with safety standards. ## Timeline ### 2026-08-11: Selenium detected in Maui water system Trace levels of selenium were detected in Maui's Wailuku water system, but officials confirm levels remain well below federal safety standards and pose no likely public health risk. 2 sources. https://clstr.news/cluster/selenium-detected-in-maui-water-system ### 2026-07-17: Maui water system reports trace selenium levels well below safety limits Maui's Makawao water system detected selenium at 3.7‑4.9 µg/L, well under the 50 µg/L safety limit, posing no health risk; monitoring continues. 2 sources. https://clstr.news/cluster/maui-water-system-reports-trace-selenium-levels-well-below-safety-limits --- Cite as: Selenium detection in Maui water systems. CLSTR, https://clstr.news/situations/selenium-detection-in-maui-water-systems