TRACE LEVELS OF SELENIUM DETECTED IN WAILUKU WATER SYSTEM

HONOLULU - Trace levels of selenium have been detected for the first time in water samples collected at Waiheʻe Wells 1, 2 and 3 Chlorinator, as well as Kupaa Well 1 Chlorinator, which are part of the County of Maui Department of Water Supply's (MDWS) Wailuku water system (Public Water System HI0000212) serving the Māʻalaea, Kīhei, Wailea and Mākena areas of the island of Maui.

The detected selenium levels ranged from 2.4 to 6.5 micrograms per liter (ug/L), which are below the U.S. Environmental Protection Agency (EPA) and Hawaiʻi Department of Health (DOH) Maximum Contaminant Level for selenium of 50 ug/L. The detected levels are unlikely to pose a public health risk.

Selenium was detected in samples collected on May 27, 2026, and June 18, 2026. MDWS notified DOH of the initial detection via phone and email on Aug. 3, 2026. Per Hawaii Revised Statutes (HRS), Chapter 340E, Section 24, the DOH must notify the public within 14 days of being notified by the purveyor (MDWS). As a courtesy, the DOH allowed MDWS to issue its notification first.

Map of the service area of Wailuku Water System (Māʻalaea, Kīhei, Wailea and Mākena)

Selenium is a naturally occurring mineral element that is distributed widely in nature in most rocks and soils. The presence of selenium in drinking water can be attributed to the erosion of natural mineral deposits.

To date, MDWS is and continues to be in compliance with the federal and state selenium standard for drinking water. Impacted users can contact the MDWS at [email protected] and 808-270-7816.

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