Chicago Water Treatment Transition

The Village receives Lake Michigan source water, which is treated by the City of Chicago and transmitted from Chicago to the DuPage Water Commission (DWC).  DWC does not conduct any water treatment but only conveys the treated water from Chicago to the Village, which the Village then distributes to its customers. 

Over the next few months, the City of Chicago will change its water treatment methods. Chicago has been utilizing blended phosphates (polyphosphates and orthophosphate) to reduce lead levels in potable water in its treatment process. These phosphates form a protective coating inside a customer's lead service lines. Chicago will transition from a blended phosphate process to treating the water with only orthophosphate. The change in process aims to further reduce lead levels from a customer's lead service lines.

Chicago has been working with the IEPA and their consultant, CDM Smith, to prepare for this transition. The City of Chicago has shared that orthophosphate is already used nationwide with other water treatment plants and plants that draw and treat water from Lake Michigan. Chicago has stated that no change should be noticed in the daily operations or water quality levels of any suburban customers who receive water from Chicago. In areas in the distribution system with dead-ends, there may be discoloration in the appearance of the water. The Village asks you to contact the Public Works Department (630)350-3435 if this should occur, and the Utilities division will flush the pipe segment to remove the discoloration in the water.

The DWC has coordinated with Cornwell Engineering to understand and monitor Chicago's implementation plan for this water treatment change.  Chicago has provided a public website and FAQ for individuals interested in obtaining more information at https://chicagowaterquality.org/corrosioncontrol/wholesale.  You can also contact the Chicago Department of Water Management Bureau of Water Quality at 312-744-8190 with further questions.   Chicago has indicated that temporary water discoloration is likely the most common issue.  Should this occur, please contact the Village's Public Works Department at (630) 350-3435 so flushing of the water mains in the area can occur.