Battle Creek officials reported that recent testing shows improving levels of total trihalomethanes (TTHMs) in the municipal water system, but a federal drinking-water violation remains in effect because the running annual average (RAA) is still above the maximum contaminant level (MCL) of 80 parts per billion, Mayor Mark Behnke said in the July 15 mayor’s report.

Quarterly testing from May indicates that the most recent TTHM samples no longer exceed the federal MCL at monitoring locations, the mayor said. However, the RAA is calculated from the most recent four quarterly samples, and earlier elevated readings continue to push the annual average above the limit. Until older results are replaced by consistently lower readings, the violation remains in effect.

The violation affects water customers in the city of Battle Creek, Springfield, Emmett Township and portions of Penfield Township, the mayor said. The city’s water division sent affected customers a letter detailing the latest results and ongoing corrective actions; the letter is posted at battlecreekmi.gov.

City officials described several steps intended to reduce TTHM formation and lower the RAA: adjusting treatment processes, completing the annual hydrant flushing program to remove older water and sediment, increasing sampling at the Verona well field and throughout the distribution system, conducting quarterly operational evaluations to assess water age and tank cycling, and replacing aging wells at the Verona well field to improve long-term water quality. The mayor said these actions are expected to continue lowering TTHM levels until the RAA returns below the federal standard.

Why this matters: TTHMs are disinfection byproducts that form when chlorine reacts with organic matter in water; federal rules set an MCL of 80 ppb for TTHMs to protect public health. The city’s statement indicates corrective steps but does not specify when the RAA will fall below the MCL.

Residents with questions were directed to the city’s 311 line at (269) 966-3311 and to battlecreekmi.gov for the posted letter and further updates.