Trace levels of selenium detected in Wailuku water system

Routine water quality testing identified trace levels of selenium in the County of Maui Department of Water Supply (DWS) Wailuku water system, which serves the Māʻalaea, Kīhei, Wailea and Mākena areas.

The initial detection occurred in samples collected on May 27, 2026, with follow-up testing from a sample collected on June 18, 2026, confirming selenium levels ranging from 2.4 to 6.5 micrograms per liter. DWS notified the Hawaiʻi Department of Health in accordance with state requirements.

The levels detected in the Wailuku water system are well below the drinking water standard. According to the US Environmental Protection Agency and DOH, the Maximum Contaminant Level for selenium in drinking water is 50 micrograms per liter. 

“Our team of water professionals continues to monitor, maintain and care for our water system,” DWS Director John Stufflebean said. “Through routine testing, we can detect even very small amounts of elements in our water system and ensure we continue providing safe, reliable water to our community.”

Selenium is a naturally occurring mineral element found in soil, rocks and certain mineral deposits. Small amounts of selenium can enter drinking water sources through the natural erosion of mineral deposits.

DWS is required to notify DOH whenever selenium is detected in a public water system. DWS will continue working closely with DOH and monitoring the Wailuku water system to maintain compliance with federal and state drinking water standards.

For more information, contact the County DWS at 808-270-7550.