Testing shows St. Charles water met or exceeded safe levels; city replacing lead pipes

As St. Charles continues to explore for a new drinking water well, the city announced the current drinking water “meets or exceeds” all Illinois Environmental Protection Agency drinking water regulations.

The city must test its water supply annually in accordance with the Safe Drinking Act. The most recent results are from water tested in 2025.

St. Charles residents currently receive their water from two separate underground aquifers. The city consumes around 4.5 million gallons per day. The city recently said its staring down a water deficiency of 500,000 gallons per day to accommodate the city’s long-term growth.

St. Charles currently has around 250 miles of water mains and seven water supply wells. A well project was recently completed, and a new one is will be completed in 2027.

The city believes a new shallow aquifer well will help it cover the projected water deficiency.

Because St. Charles sources its water from the deep and shallow well system, no lead is in the water harvested. Lead is not currently in the water mains that connect all the city’s homes and businesses but is instead in the water service lines. Lead in water service lines is especially common if the building is more than 30 years old.

The city is currently replacing around 3,400 lead and galvanized water service lines. The $84 million project is mandated by the state over a 10-year period.

According to the report, the city’s water was last tested for PFAS in 2020. The test indicated the city’s water was below the state’s health advisory level. The city said follow-up monitoring is currently being conducted.

Reporting violation on lead and copper

Included in the report is that the city was found by the state to be in violation for testing regarding lead lines and information on how to access lead and copper sample results.

“The 2025 report was also missing the lead and copper range of detections lead 0 to 11 ppb and copper 0.009 to 0.511 ppm,” the report says.

Those detections meet the Illinois safety standards.

The report says the violation was due the city’s contracted lab “not properly” submitting all sample results to the IEPA prior to the required date. The report says the sample results were submitted once it was discovered and that the city is currently changing the contracted lab service.

The city said the 2026 report will have the updated information regarding the samples.

You can read the full report by visiting, stcharlesil.gov.