Wellton water system exceeds drinking-water standard for TTHMs

Wellton's water system posted a second-quarter 2026 total trihalomethanes level of 0.120 milligrams per liter, 0.040 mg/L above the drinking-water standard of 0.080 mg/L, in a notice dated July 6. The exceedance was not an emergency and did not require residents to boil water or take immediate corrective action.

The town warned that people with compromised immune systems, infants, pregnant people and older adults may want to talk with a health care provider before drinking the water. It also said long-term exposure above the standard may affect the liver, kidneys or central nervous system and may raise cancer risk.

TTHMs are four volatile organic chemicals that form when disinfectants react with natural organic matter in water. Wellton's first-quarter 2026 notice put the running average for fourth-quarter 2025 at 0.111 mg/L, while an Aug. 21, 2024 notice put the 12-month average at 0.083 mg/L, just above the standard.

Wellton Town of, water system AZ0414022, is in Yuma County and has a TTHM operational evaluation level compliance schedule due June 29, 2026. Wellton is working with the Arizona Department of Environmental Quality, engineers and different treatment techniques to resolve the problem within the next year.

The notice asked residents to pass the information along to other water users, including people in apartments, nursing homes, schools and businesses. Wellton lists Utility and Accounts Payable Clerk Mary Miranda as the water-department contact.