08/04/2026
FROM O’FALLON CITY HALL FOR IMMEDIATE RELEASE
ANNUAL WATER SYSTEM TREATMENT BEGINS ON AUGUST 17, 2026
O’Fallon, Illinois - August 3, 2026 – On August 17th, 2026, Illinois American Water will begin the annual maintenance of their water system. Illinois American Water’s water quality team will be switching treatment to a form of chlorine known as “free chlorine,” which does not contain ammonia. The City of O’Fallon will be notified when they go back to the normal type of disinfectant in approximately two months.
During the temporary treatment change, customers may experience a more noticeable chlorine taste or odor in their water. There is no reason for concern. This is due to the switch in chlorine types. Institutions with additional water purification filters for special needs, for instance hospitals and dialysis centers, have been contacted about this work and are aware of the treatment change. Anyone with questions about home health care equipment should reach out to their health-care provider.
The City of O’Fallon buys treated water wholesale from the private company, Illinois American Water, and then pumps it to all water customers. Therefore, Illinois American Water will be treating the water prior to its delivery to the City of O’Fallon’s pumping station.
If you would like more information about this topic, please contact O’Fallon Public Works at 618-624-4500 x 3
