ST. CHARLES — The federal Environmental Protection Agency has ordered the city to stop running one of its drinking-water wells for testing purposes.
In a letter Monday to city officials, the federal agency said it agreed with Ameren’s concern that the renewed use of well No. 4 for testing may be resulting in the spread of contamination from the area of an Ameren substation.
The well, which hasn’t been used to produce city drinking water since 2005, was one of six wells shut down over the years by St. Charles because of contamination in the wellfield.
The city’s utilities superintendent, John Phillips, said the city had hoped to eventually begin using the well again for drinking water, with contaminants removed by a new filtration system the city has installed at its water treatment plant. Since Aug. 7, the well had been running again just as a test.
Ameren released a copy of an email sent by EPA to St. Charles officials on the issue after the city announced it had shut down the well on Wednesday as directed by EPA.
An Ameren spokesman also reiterated the electric utility’s criticism of the city’s recent use of the well for testing.
“The decision by the City to use this decades-old, obsolete well for the first time in approximately 20 years in an attempt to undermine remediation activities was irresponsible,†the spokesman said.
Phillips, the city official, denied that the city was trying to hinder Ameren’s efforts.
The city earlier this month asked the St. Charles County Circuit Court to bar Ameren from drilling an extraction well at the substation. Ameren on Thursday afternoon said it had asked that the case be moved to the federal courts.
The city and the electric utility have been sparring over the past year over groundwater contamination stemming from cleaning solvents used many years ago at the substation.
Ameren has been doing groundwater cleanup for the past decade. The EPA has said the city’s water system remains safe and that wellfield contaminaton hasn’t exceeded allowable levels.
