ST. CHARLES, Mo.—Only one water well remains operational in the city of St. Charles after City Well 4 had to be shut down due to contamination, according to the city. 

The Environmental Protection Agency (EPA) directed the city to stop operations at that well because it tested positive for vinyl chloride. A news release from the city says a failed barrier at an Ameren substation didn’t contain the the chemical.

St. Charles has been dealing with well contamination issues since 2005. The city operates seven wells in the Elm Point Wellfield. 

Previously, Spectrum News reported the city announced it shut down its sixth well in February of 2023. A St. Charles spokesperson told us Wednesday one of the wells had reopened, but didn’t specify when. 

The city has asked the EPA to immediately provide a plan to restart wells safely to restore the water system capacity of 6 million gallons per day.  Spectrum News has reached out to the EPA for a comment.

The city has been purchasing drinking water from other areas for its residents for several years. The mayor says it comes at a financial burden for the city, which has dipped into its emergency fund to pay the bill.

EPA tests conducted in January identified an Ameren substation as the source of contamination at the Elm Point Wellfield. Ameren has already begun implementing several aggressive treatment techniques with additional steps to be taken soon.

Earlier this year, an environmental consulting firm hired by the city says the current water treatment plant does not have the necessary equipment to remove the chemicals from the drinking water. 

Ameren Missouri has previously said it remains committed to the safety of St. Charles residents and says the drinking water is safe.

The city filed a suit against Ameren in May seeking millions of dollars in damages and to reimburse the city for expenses dealing with the contamination.