ST. CHARLES, Mo. – The City of St. Charles has been down to one functioning well for drinking water since mid-February due to contamination of hazardous chemicals.

That could change next week.

Utility crews recently installed a granular activated carbon (GAC) treatment system at the city’s water treatment plant. On Wednesday, the city asked the Environmental Protection Agency to restart three of its drinking wells on Oct. 10.

If approved, wells CW-6, CW-7, and CW-8 will be activated to flush water through those wells for treatment. When the city confirms the treatment at those water wells is successful, it will shut down CW-10, the city’s only operating well, for much-needed maintenance.

The city will also resume operation at wells CW-5 and CW-9 in order to achieve full capacity.

According to the city, the EPA has promised that Ameren Missouri will conduct immediate and biweekly testing on all the restarted wells for the next three months.

In October 2022, St. Charles Mayor Dan Borgmeyer said the majority of the city’s water wells had been shut down due to contamination with hazardous chemicals. By December, the city had shut down five of its seven wells. Ameren’s Huster Road Substation, located near the Elm Point Wellfield, was leaking carcinogens into the soil and groundwater, Mayor Borgmeyer said at the time.

In the 1970s, Ameren Missouri used a scouring solvent called tetrachloroethylene to clean equipment at the substation, according to Paul Michalski, a senior hydrogeologist for 212 Environmental. Ameren attempted to degrade the chemical in soil and groundwater. Two carcinogens were created in the process: cis-1,2-Dichloroethene and vinyl chloride, both of which are harmful to human beings.

In January 2023, the EPA collected both ground and water samples from the Elm Point Wellfield. Lab results confirmed the presence of both cis-1,2-Dichloroethene and vinyl chloride and in February, the EPA identified the Ameren substation as the source.

This past August, the City of St. Charles briefly shut down Well 10 following a drop in the free level of ammonia in raw water and had to rely entirely on St. Louis City for its water needs.

St. Charles has purchased additional water from St. Louis since 2017.